We need a more global-oriented higher education policy :
Professor Wiswa Warnapala,
Minister of Higher Education of Sri Lanka
The purpose of this meeting is to enter into an active dialogue with the Vice Chancellors of the Universities of Sri Lanka, and the primary aim of the dialogue is to make use of the experience of the distinguished Vice Chancellors in formulating a new Higher Education policy for the country. The objectives of Higher Education, due to a wide variety of reasons, have undergone a change, and the University system, which came into existence in 1921 with the establishment of a University college which was later elevated to the status of a fully fledged University in 1942, fulfilled its tasks and the system expanded to such an extent that Sri Lanka has a fairly developed University system which has had a considerable influence on the intellectual life of the country. With this expansion and the nature of its contribution, no proper policy perspectives have been advanced to bring about changes in the system to make it more meaningful and relevant. In other words, the system did not expand in relation to the social and economic development needs in the county and the guiding factor in the expansion was the need to provide access to higher education, which became an immediate need as a result of the impact of the Free Education Scheme. Today we are living in a new millennium, and the 21st century is the most advanced period in the history of mankind, most advanced period in terms of knowledge as well.
In a rapidly changing world dominated and driven by knowledge, we need to give preference to the important objectives of Higher Education. In other words, the Higher Education institutions must give consideration to both relevance and quality, and it is on this basis that the Higher Education institutions in Sri Lanka can become real partners in the social and economic choices of a society. The greatest challenge in the 21st century for higher Education is the
recognition of relevance. By relevance, we mean the need to adapt to the immediate needs of the job market. This, in other words, means that the Universities should produce an employable graduate. Through the universities, we need to prepare individuals to contribute to the
social and economic development and this could be fruitfully achieved if the undergraduates are provided with the relevant skills and the knowledge. It is in this context that Higher Education needs to be defined as a public service. Higher Education can also be defined as one, which contributes to cultural, economic and social development within the context of pluralism and cultural diversity. It is accepted that Higher Education, in any given society, developed or
developing, has to play a role in the production and transmission of knowledge. Knowledge is universal and it has become the heritage of mankind. How can we convert Universities into knowledge institutions?
The institutions in the sphere of Higher Education need to be encouraged to perform an active, creative and innovative role to help the society to change. In other words, Universities should function as development institutions - institutions which promote and encourage development; this means that Universities have a development role in a country. Can we say this in respect of the Universities in Sri Lanka? Have they contributed to the process of development? In the last, fifty years, they, undoubtedly, made a noteworthy contribution in producing an educated labour force and advanced human capital. In addition, they helped in the establishment of an active intellectual enterprise as well. In order to ensure full recognition of the role of Higher Education for social and economic development, certain vital considerations are necessary; two of the
basic considerations are :
(1) the need for institutional autonomy and
(2) academic freedom.
Sri Lankan Universities, from their inception, enjoyed these things and they came to be institutionalised as a result of the influence of the British academic tradition. Next important thing was the revision of study programmes in the Universities; the modernisation and the
diversification of academic programmes was yet another vital requirement. It is here in this context that we need to look at the relevance of interdisciplinary studies and multi-disciplinary
studies. This is very much of a fashionable thing in the modern University whereas compartmentalization was made in the 190' and 20th century. Sri Lankan Universities, due to the dominance of the traditional disciplines, still believe in compartmentalization of
subjects, and this academic culture must undergo a transformation. In my view, international partnerships and international cooperation could bring about a change and the introduction of inter-disciplinary courses could also enhance quality.
I would like to draw your attention to the need to promote more and more research in the Universities. Universities should have a research mission, and it needs to be re-stated from the perspective of contributing to development. Yet another fact is that research must focus on local and global needs and issues, social and economic issues, and the universities, through this kind of research, could enter the international sphere. No need to do research for the sake
of doing research; research should be done with a relevance and it could be social relevance and developmental relevance. Research should also focus towards preparing students for Higher Education; in other words, students also should benefit from research. In the developing countries, research need to be made relevant to the needs of the country. The Government also must promote education systems and institutions that are capable of efficiently adapting to changes in the social and economic environment. Today there is a strong need for a clear definition of the overall priorities and development policies. Steps need to be taken to improve the capacity of the Higher Education institutions, which must show their readiness to
accept the national priorities.
There is yet another sector to which we need to pay attention, and it is the responsibility of Higher Education institutions towards other education levels. This relationship is lacking in Sri Lanka, and the Universities hesitate to promote links with other sectors. Such a tradition does not exist, and it, in fact, was due to the isolationist attitude of the colonial University. The relationship with the schools sector is very limited and it is confined to some of the services rendered for the Advanced Level Examination. An active relationship with the schools sector would ensure that students are better prepared for Higher Education. Such a relationship, in my
view, could be developed by the provision of resources and expertise, teacher-training programmes, socico-economic research and educational policy alternatives and such things would help to improve education at all levels. Access to Higher Education, in terms of the rates in developed countries is still insufficient, and the Government, therefore, must take measures to expand and diversity the opportunities for every citizen to benefit from higher-level skills
and qualifications - with which they can enter the world of work. The concept of employability needs to be advocated and articulated. Still the participation rates in Higher Education are poor, and this despite the country's achievements in equality of opportunity, universal primary education and near gender equality. Participation rates need to be increased, for which appropriate policies are necessary. In the area of traditional Higher Education, not much
attention is paid to productive public sectors. Higher Education institutions should promote continuous partnerships with productive sectors in the country; they must help shape the labour market, and this demands the introduction of entrepreneurial skills and the creation of self-employment opportunities. This is where the curricula demands, diversification. Universities could think in terms of introducing more and more Diploma and Certificate courses; work
experience could be regarded as a part of a Diploma course and this kind of a system is well established in developed countries. Such innovations are immediately necessary in our Universities. In the current international context, changes are necessary and they could
embody the following :
1. The development of an entrepreneurial culture in the Universities;
2. a policy on intellectual property;
3. industrial research;
4. revision of personnel policies.
5. systematic staff re-appraisal;
6. development of professional administrators;
7. removable contracts and permanent tenure;
8. attractive salary packages;
9. curriculum reforms;
On the basis of such changes, the modern University should become more responsive to the varying needs of the society. It needs to be emphasised that relevance cannot be achieved at the expense of quality. The Government, in its role as the major player of the system, should try to establish policies of continual search for improvement and innovation. An innovative approach is necessary if the Universities are to be made more modern and relevant for the
process of development.
In Sri Lanka, the system and modes of university administration have remained unchanged for a long period of time. Influence of the colonial legacy still remains and they are an impediment for
modernisation. For instance, any attempt to reform is certain to be perceived as an attempt to disrupt the system. Adaptation and acceptance for change are immediately necessary. In Sri Lanka, there is not much of a relationship between the University and non - University sectors whereas this relationship is a vital combination in other parts of the world. Non-University Higher Education institutions should be encouraged to provide more access. In all developed countries, these are two well- established sectors - University and Non-University sectors. Most countries tend to treat both as one, and it serves a useful purpose in terms of academic attainments and qualifications. Unfortunately, Sri Lanka, for some strange reason, does not encourage this combination and it is vitally necessary if we intend to provide the citizen with quality education.
The recognition of this strategy would result in (1) greater social demand for higher education,
(2) the need to cater to the diverse needs of students;
(3) emergence of new professional fields and
(4) the expansion of knowledge, based on inter- disciplinary and multi-disciplinary approaches.
Yet another important aspect is the State control of Higher Education. State as the major player, has to look at three issues in promoting Higher Education and the issues are quality, efficiency and equity. Sri Lanka, for instance, has a traditional State control model, and the World Development Report of 1997, making a general comment, stated that Government rules are not enough to bring about reforms in the sector. It is here in this context, that we need to
examine the relationship between the State and Higher Education institutions. Two features dominate the system - the degree of centralised control and the great deal of institutional autonomy.
These things have come to stay and they are legacies of the system, which we inherited at independence.
In the Sri Lankan experience, the traditional predominant role of the State in the provision of Higher Education is rooted in the political culture based on the Free Education scheme of 1944. The system remains well established and what needs to be done in the given context is the introduction of innovative changes so that the system can be made more functional and efficient. Adjustments, therefore, are necessary for the efficient functioning of the modern University.
What the country needs is a coherent higher education policy framework and the formation of a vision for the long- term development of a comprehensive and diversified Higher Education
system, which can contribute to national growth.
With thanks to © THE ISLAND. 2007.
Tuesday, 15 May 2007
Thursday, 10 May 2007
Ooranis - Ramanathapuram District India - Dhan Foundation
A word on Ramanathapuram District :
Ramanathapuram district is drought prone and water scarcity is the biggest problem here.
People migrate after January and return by August when the monsoon sets in. The northeast monsoon (September to November) is expected to bring maximum rain and usually chilli, cotton, onion and paddy are cultivated. Charcoal is produced in Ramanathapuram and adjacent Tuticorin districts. Agriculture, charcoal production and fishing in the coastal areas are the sources for livelihood of the people. There are some industries in nearby Virudhunagar district where people migrate for work. A good number of workers in hosiery and knitwear units of Tiruppur are from the district. Usually men go out in search of jobs and women, old people and children stay home.
Once upon a time the ooranis and tanks had been maintained by the people through a group of individuals chosen by the villagers and called kudimaramatthu . This practice stopped after the British regime took over.
Tanks and ooranis became Government property maintained by the Public Works Department. With the arrival of bore wells, the concept of conserving water through such water bodies was forgotten.
The ground water level plummeted and water turned saline. The Government-sponsored desalination plants in the district are insufficient to meet the demand.
Every village has one to three ooranis for drinking water, domestic water needs and livestock and temple pond. The main water source is rain, but the district falls in rain shadow belt with scanty rainfall.
People could at most store water in ooranis and tanks for three to six months a year.
Rest of the time women, girls and men must trek three to five kilometers every day in search of water. This affected their livelihood, health, and the education of girls. There are incidents of conflicts for drinking water among villages. On the other hand there are instances of sharing oorani water between villages. If an oorani is built, the water would be shared by about 500 families of three villages.
Most of the ooranis are either dilapidated or small. In some areas, the percolation rate of water is high because the base layer is sandy. If an oorani is renovated and technically modified, it would quench the people's thirst in three to four villages. Besides it would improve the quality of life. Girls could go to schools; women could finish their household chores faster and help in the fields. The search for water has affected health, education and livelihood. It is common to find men and women in the district spending a whole day in search of water. The family income is Rs.1, 500 to Rs. 2,500 a month and lower during the summer. People have to spend Rs.150 to Rs.250 on water every month.
You can also do it ….
To help save the lives of the Life saving Ooranis -
Kind hearted well-wishers -- Can sponsor an Oorani
Dhan Foundation - http://www.dhan.org/ooranis/districts.php
Ramanathapuram district is drought prone and water scarcity is the biggest problem here.
People migrate after January and return by August when the monsoon sets in. The northeast monsoon (September to November) is expected to bring maximum rain and usually chilli, cotton, onion and paddy are cultivated. Charcoal is produced in Ramanathapuram and adjacent Tuticorin districts. Agriculture, charcoal production and fishing in the coastal areas are the sources for livelihood of the people. There are some industries in nearby Virudhunagar district where people migrate for work. A good number of workers in hosiery and knitwear units of Tiruppur are from the district. Usually men go out in search of jobs and women, old people and children stay home.
Once upon a time the ooranis and tanks had been maintained by the people through a group of individuals chosen by the villagers and called kudimaramatthu . This practice stopped after the British regime took over.
Tanks and ooranis became Government property maintained by the Public Works Department. With the arrival of bore wells, the concept of conserving water through such water bodies was forgotten.
The ground water level plummeted and water turned saline. The Government-sponsored desalination plants in the district are insufficient to meet the demand.
Every village has one to three ooranis for drinking water, domestic water needs and livestock and temple pond. The main water source is rain, but the district falls in rain shadow belt with scanty rainfall.
People could at most store water in ooranis and tanks for three to six months a year.
Rest of the time women, girls and men must trek three to five kilometers every day in search of water. This affected their livelihood, health, and the education of girls. There are incidents of conflicts for drinking water among villages. On the other hand there are instances of sharing oorani water between villages. If an oorani is built, the water would be shared by about 500 families of three villages.
Most of the ooranis are either dilapidated or small. In some areas, the percolation rate of water is high because the base layer is sandy. If an oorani is renovated and technically modified, it would quench the people's thirst in three to four villages. Besides it would improve the quality of life. Girls could go to schools; women could finish their household chores faster and help in the fields. The search for water has affected health, education and livelihood. It is common to find men and women in the district spending a whole day in search of water. The family income is Rs.1, 500 to Rs. 2,500 a month and lower during the summer. People have to spend Rs.150 to Rs.250 on water every month.
You can also do it ….
To help save the lives of the Life saving Ooranis -
Kind hearted well-wishers -- Can sponsor an Oorani
Dhan Foundation - http://www.dhan.org/ooranis/districts.php
Tuesday, 8 May 2007
Radar Reveals Remains at Angkor
MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Contact: Mary A. Hardin (818) 354-0344
FOR IMMEDIATE RELEASEFebruary 12, 1998
NASA RADAR REVEALS HIDDEN REMAINS AT ANCIENT ANGKOR
New evidence of a prehistoric civilization and remnants of ancient temples in Angkor, Cambodia have been discovered by researchers using highly detailed maps produced with data from an airborne imaging radar instrument created by NASA.
Experts say the findings, made possible by the Airborne Synthetic Aperture Radar (AIRSAR) developed by NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA, may
revolutionize the way archaeologists view the ancient city's development.
Angkor is a vast complex of some 1,000 temples covering more than 160 square kilometers (about 100 square miles) of northern Cambodia. Little is known of the prehistoric occupation of this fertile flood plain, but at its height the city housed an estimated population of 1 million people. The famous temples were built from the 8th to 13th century AD and were accompanied by a massive hydrological
system of reservoirs and canals.
Today, much of the civilization of Angkor is hidden beneath a dense forest canopy and is inaccessible due to poor roads, land mines and political instability.
"The radar data have enabled us to detect a distribution of circular 'prehistoric' mounds and undocumented temples far to the northwest of Angkor," said Dr. Elizabeth Moore, Head of the Department of Art & Archaeology at the School of Oriental and African Studies at the University of London. "The site's topography is highlighted by the radar, focusing our attention on previously neglected features, some at the very heart of the city.
"The radar maps not only bring into question traditional concepts of the urban evolution of Angkor, but reveal evidence of temples and earlier civilization either absent or incorrect on modern topographic maps and in early 20th century archaeological reports," she said.
"The radar images make apparent many features that are not readily identifiable on the ground," said Dr. Anthony Freeman, a radar scientist at JPL who has collaborated with Moore for the past three years studying the use of radar on the Angkor site. "We can see differences in vegetation structure and some features that are
obscured by vegetation cover."
In December 1997, Moore surveyed a small mound on the perimeter of the famous 12th century AD temple, Angkor Wat, that Freeman had first noticed in the radar image.
"Previous archaeological accounts from 1904 and 1911 note only two temples and make no mention of the distinct circular form of the mound. We found four to six temple remains, including pre-Angkorean structures," Moore said. "This suggests occupation of the 12th century site some 300 years earlier, radically changing accepted chronologies of Angkor."
Angkor's beauty is seen its in temples, but the greatness of the Khmer city lies in the multitude of water-related constructions, according to Moore. The Khmer kings
nominally dedicated temples to Hindu and Buddhist deities, but the underlying significance was veneration of ancestral spirits, ensuring fertility of the land.
Management of water was essential, both for control during the monsoon
rains and conservation during the dry season and involved the construction of moats, dikes, canals, tanks, and reservoirs. The largest of these reservoirs, dated to the 12th century AD, is eight kilometers (five miles) long and its function remains a matter of archaeological debate.
"These new detailed topographic maps have shown us many more hydrological features and highlighted how they function in the rituals and daily life of the Khmer people," Moore explained.
"Using a technique known as radar interferometry, which combines two images to create a three-dimensional topographic map, we can construct a map of the area surrounding Angkor that is more accurate than most maps we have of the United States," said Dr. Scott Hensley, a radar engineer at JPL. "This map lets us see both natural and human-made water management features at the site with great clarity."
"Angkor is situated on the edge of the Tonle Sap lake, a unique body of water that doubles in size during the rainy season. These maps give us new insights into the human impact on this ecosystem, from the ancient Khmer to the present day, and are of importance in the study of our changing Earth," Freeman continued.
The Angkor radar images were taken in late 1996 as part of the AIRSAR Pacific Rim Deployment and were a follow-up to the 1994 study of Angkor with data collected by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) that flew on NASA's Space Shuttle Endeavour.
Like SIR-C/X-SAR, AIRSAR transmits and receives three radar frequencies in both horizontal and vertical polarizations. While both systems use C-band and L-band wavelengths, AIRSAR has the added benefit of P-band, a longer wavelength that can penetrate below the forest canopy. In addition, AIRSAR can be flown in a mode called TOPSAR that allows it to measure topography and create three-dimensional images of the surface.
AIRSAR images of the Angkor region will be posted to the Internet at this address:
http://www.jpl.nasa.gov/news/
AIRSAR flies on a NASA DC-8 aircraft that is managed at NASA's Dryden Flight Research Center, Edwards, CA. The AIRSAR instrument is managed by JPL, a division of
the California Institute of Technology for NASA's Office of Earth Sciences, Washington, DC. This office manages NASA's Earth Science enterprise, an
internationally coordinated effort to study natural and human-induced changes in the Earth's land, oceans, atmosphere, ice and life.
The AIRSAR flight over Cambodia was funded by the Government of Thailand. Ground verification has been made possible by Vann Molyvann, Minister of State for Culture and Fine Arts, Territorial Management, Urban Planning and Construction; and Dr. Ang ChoulĂan of the Cambodian Authority for the Protection and Management of Angkor and the Region of Siem Reap.
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Contact: Mary A. Hardin (818) 354-0344
FOR IMMEDIATE RELEASEFebruary 12, 1998
NASA RADAR REVEALS HIDDEN REMAINS AT ANCIENT ANGKOR
New evidence of a prehistoric civilization and remnants of ancient temples in Angkor, Cambodia have been discovered by researchers using highly detailed maps produced with data from an airborne imaging radar instrument created by NASA.
Experts say the findings, made possible by the Airborne Synthetic Aperture Radar (AIRSAR) developed by NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA, may
revolutionize the way archaeologists view the ancient city's development.
Angkor is a vast complex of some 1,000 temples covering more than 160 square kilometers (about 100 square miles) of northern Cambodia. Little is known of the prehistoric occupation of this fertile flood plain, but at its height the city housed an estimated population of 1 million people. The famous temples were built from the 8th to 13th century AD and were accompanied by a massive hydrological
system of reservoirs and canals.
Today, much of the civilization of Angkor is hidden beneath a dense forest canopy and is inaccessible due to poor roads, land mines and political instability.
"The radar data have enabled us to detect a distribution of circular 'prehistoric' mounds and undocumented temples far to the northwest of Angkor," said Dr. Elizabeth Moore, Head of the Department of Art & Archaeology at the School of Oriental and African Studies at the University of London. "The site's topography is highlighted by the radar, focusing our attention on previously neglected features, some at the very heart of the city.
"The radar maps not only bring into question traditional concepts of the urban evolution of Angkor, but reveal evidence of temples and earlier civilization either absent or incorrect on modern topographic maps and in early 20th century archaeological reports," she said.
"The radar images make apparent many features that are not readily identifiable on the ground," said Dr. Anthony Freeman, a radar scientist at JPL who has collaborated with Moore for the past three years studying the use of radar on the Angkor site. "We can see differences in vegetation structure and some features that are
obscured by vegetation cover."
In December 1997, Moore surveyed a small mound on the perimeter of the famous 12th century AD temple, Angkor Wat, that Freeman had first noticed in the radar image.
"Previous archaeological accounts from 1904 and 1911 note only two temples and make no mention of the distinct circular form of the mound. We found four to six temple remains, including pre-Angkorean structures," Moore said. "This suggests occupation of the 12th century site some 300 years earlier, radically changing accepted chronologies of Angkor."
Angkor's beauty is seen its in temples, but the greatness of the Khmer city lies in the multitude of water-related constructions, according to Moore. The Khmer kings
nominally dedicated temples to Hindu and Buddhist deities, but the underlying significance was veneration of ancestral spirits, ensuring fertility of the land.
Management of water was essential, both for control during the monsoon
rains and conservation during the dry season and involved the construction of moats, dikes, canals, tanks, and reservoirs. The largest of these reservoirs, dated to the 12th century AD, is eight kilometers (five miles) long and its function remains a matter of archaeological debate.
"These new detailed topographic maps have shown us many more hydrological features and highlighted how they function in the rituals and daily life of the Khmer people," Moore explained.
"Using a technique known as radar interferometry, which combines two images to create a three-dimensional topographic map, we can construct a map of the area surrounding Angkor that is more accurate than most maps we have of the United States," said Dr. Scott Hensley, a radar engineer at JPL. "This map lets us see both natural and human-made water management features at the site with great clarity."
"Angkor is situated on the edge of the Tonle Sap lake, a unique body of water that doubles in size during the rainy season. These maps give us new insights into the human impact on this ecosystem, from the ancient Khmer to the present day, and are of importance in the study of our changing Earth," Freeman continued.
The Angkor radar images were taken in late 1996 as part of the AIRSAR Pacific Rim Deployment and were a follow-up to the 1994 study of Angkor with data collected by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) that flew on NASA's Space Shuttle Endeavour.
Like SIR-C/X-SAR, AIRSAR transmits and receives three radar frequencies in both horizontal and vertical polarizations. While both systems use C-band and L-band wavelengths, AIRSAR has the added benefit of P-band, a longer wavelength that can penetrate below the forest canopy. In addition, AIRSAR can be flown in a mode called TOPSAR that allows it to measure topography and create three-dimensional images of the surface.
AIRSAR images of the Angkor region will be posted to the Internet at this address:
http://www.jpl.nasa.gov/news/
AIRSAR flies on a NASA DC-8 aircraft that is managed at NASA's Dryden Flight Research Center, Edwards, CA. The AIRSAR instrument is managed by JPL, a division of
the California Institute of Technology for NASA's Office of Earth Sciences, Washington, DC. This office manages NASA's Earth Science enterprise, an
internationally coordinated effort to study natural and human-induced changes in the Earth's land, oceans, atmosphere, ice and life.
The AIRSAR flight over Cambodia was funded by the Government of Thailand. Ground verification has been made possible by Vann Molyvann, Minister of State for Culture and Fine Arts, Territorial Management, Urban Planning and Construction; and Dr. Ang ChoulĂan of the Cambodian Authority for the Protection and Management of Angkor and the Region of Siem Reap.
Buddhist Water Management
Ecosystem Based Indigenous Water Management :
From Link - http://www.janathakshan.org/gats_reforms/b/Ecosystem.html
Practical Action (Formerly ITDG)
5, Lionel Edirisinghe Mawatha, Colombo 5, Sri Lanka
Ecosystem based indigenous water management :
1. Background of the report :
The main objective of this report is to give a basic introduction about our indigenous water management. Actually it can be described as ecosystem management. In this regard physical structures, practices as well as cultural aspects (concepts, attitudes economic development model etc) related to this ecosystem management will be briefly out lined.
Indigenous water-ecosystem management cannot be simplified to its physical structures and practices. Presently, the physical structures and practices are taken isolated from the cultural aspects and then the governing economic development model has little meaning. Therefore the intention of this report is to introduce both of these aspects of indigenous water ecosystem management in a holistic manner, and to come up with some guidelines drawn from the "indigenous water ecosystem management" which could be included in a current water policy or in a related matter to solve some of the problems related to water (ecosystem) in today's context.
2. Introduction :
Sri Lankan history is deeply connected with its hydraulic civilization. Today this hydraulic system is erroneously named as an irrigation system. Nevertheless according to most of the renowned authorities (Eng. D L O Mendis, Dr. Ray Wejewardene) in this field this was a sustainable water - soil - flora fauna - human ecosystem, which was mainly based on small tanks (Wewa) in Rajarata and Ruhuna, and basically on anicuts in Mayarata (i.e. mainly the wet zone). The history of this ecosystem leads back to the 4th century B.C. or before. Basawakkulama sometimes known as "Abhayawewa" was identified as the most ancient Wewa, which was done by king Pandukabhaya.
Ancient kings had built major tanks and village tanks simultaneously. For an example king Parakramabahu the great had constructed 165 dams, 3910 canals, 163 major tanks and 2376 village tanks during the last lap of Rajarata [13].
The backbone of this ecosystem was its ability to store the rainfall water within the system for the benefit of the whole system. Unlike in modern irrigation systems, which are focused on supplying the crop water requirement for the root-zone (zone in soil where the roots of trees and plants are spread, water is absorbed to roots in this region), the ancient "hydraulic system" was focused on the water requirement of the entire ecosystem. To fulfil this requirement, various types of structures such as major tanks, small tanks, Vetiyas, Amuna, Vila (lake), Wala (Pond) etc. (Figure 1) and inter connecting canals were constructed very much closer to the nature.
In some areas water from major rivers was conveyed to the major tanks and from there to the small tanks and then to the fields, for an example Elahera-Parakkramasagaraya. In some other areas this was happened totally the other way round, i.e. spilling out water from small-tanks was stored in major tanks. For examples Kuluwewas ( Small surface storage consisting of earth bunds used as a silt trap, flow controller for flood mitigation raising the water table in vicinity.), which are incorporated in most of the ancient systems. In almost all these cases small tanks were constructed in cascade system, which facilitated efficient reuse of water. In this manner these structures were used to store water in the ecosystem (i.e. in the soil) in drought periods and was used in flood mitigation in rainy periods. It should be mentioned here that irrigation was only a part of this hydraulic system.
As mentioned earlier the heart of this ecosystem was the wewa, which gave the lifeblood for the ecosystem. These systems have been sustained for thousands of years. The sustainability of these ecosystems is not only due to there physical structures mentioned earlier. The culture prevailed in these settlements also provided necessary conditions for this sustainability. This culture can assume to be driven not by the self-interest motivated by greed, but by the other motivation like sharing resources equally (even among animals, birds etc.) and the equity of ownership. The statement of Arahat Mahinda states that the king is only the guardian of nature and not the owner. Keeping a Kurulupaluwa (portion of paddy field reserved for birds) would have been a direct outcome of this concept. This culture with that concept proves that, we are just guardians of the nature of the physical structures like wewa to served this ecosystem to function for thousands of years. Actually, in this culture-ecosystem had the in built development model which is suitable for us i.e. our environment & culture. Now we are almost totally apart from this tradition. Today we do not have an idea about our development model and therefore we cannot rehabilitate these ecosystems in a sustainable manner. Anyhow it should be mentioned here that though we cannot go back to the same system today, the guiding principles provide important guidelines for a modern day sustainable water management policy.
3. Indigenous water management :
In the of ancient cultural context water management was not taken as an isolated issue. Hear, the main objective of water management is to optimize the conditions of the proper function of the ecosystem. Water was mainly stored, in the soil and conveyed through the soil and the soil facilitated mainly the water purification process. Water was taken from the soil (from water table) then the used water is again put to the soil, which purify the water and feed the water table for reuse. Water was conserved in the soil (i.e. maintaining the water table). To facilitate this conservation physical structures like cascade wewa system; (in Rajarata) Vetiya (in southern area) Amuna were built according to the geophysical nature of the region. In this manner water receive from the two monsoons was reused several times before it ultimately drained to the sea. Even the inter monsoon rains (Akvehi) would have facilitated this reuse process (i.e. cyclicity). The water evaporated from the wewas help to create convection rains (Akvehi)( Farmers in villagers such as Puleliya, say this by looking at the directional movements of the clouds. When the clouds are almost stationary, they identify the rains as Akvehi) i.e. evaporation from wewas is not a real loss! Also these structures facilitated flood mitigation process in the lower parts of the ecosystem in heavy rainy periods. In this context ecosystem is defined even including the man and the objects and the accessories required by him for his life.
4. Concepts, attitudes related to the sustainable-development model (for ecosystems) :
Buddhism was significantly influenced the Sri Lankan life style (e.g. attitudes, concepts). Some of such prominent Buddhist concepts are listed below.
Greed (Thanha) is the cause for sorrow Dukha. Therefore it should be decreased( Buddhist Sutrapitake - Load Buddha) .
Happiness is the most impotent wealth. ("Santhutti paramang Dhanang") ( Buddhist Sutrapitake - Load Buddha)
Equity of ownership
Attitude towards nature - nature does not belong to anybody. We are only a part of it and we can use it in a sustainable manner for our survival without much disturbing much to the other partners. Statement of Arahant Mahinda.
Less selfish, holistic community based approach to optimise the ecosystem.
Holistic approach towards nature [9].
5. Structural features and practices of this ecosystem :
5.1 Rain water trapping structures :
In the ancient water management, amount of rainfall (nowadays measured in "mm") and the intensity of rainfall (nowadays measured in "mm/day") were deliberated. Small structures like Vetiya captures the water from very low intensity rainfall. Small tanks capture the water from much higher rainfalls and major tanks capture water from even higher rainfalls [5].
5.1.1 Wewa :
There are about 12,000 small tanks and anicuts found in Sri Lanka and these tanks and anicuts irrigate an extent of about 185,000ha. This is 35% of total irrigable area in the country. Small irrigation schemes produce 191,000mt annually accounting for 20% of the national irrigated rice production (Agricultural implementation programme 1994 - 95). Following are the essential components of a village tank (figure 3).
Gasgommana - It is the upstream of the land strip located above the tank bed and water is accumulated in Gasgommana only when the tanks spill out. Naturally grown large trees such as Kumbuk, Nabada, Maila, Damba etc. and climbers such as Kaila, Elipaththa, Kakukeliya, kalawel, bokalawel etc. are subsisted in this area. The gasgommana acts as a wind barrier and at the same time it helps to reduce evaporation from the tank and to lower the water temperature. It gets closer to the bund from either side where roots of large trees make water cages creating breeding and living places for some fish species. This strip of trees demarcates the territory between human and wild animals.
Perahana - It is the meadow developed under gasgommana and filters the sediment flow coming from the upstream chena lands.
Iswetiya or potawetiya - It is the constructed soil ridge in the upstream of the tank at either side of the tank bund to prevent entering the eroded soil from upper land slopes.
Godawala - A manmade water hole to trap sediment and it provides water to wild animals. This might be a strategy used to evade man-animal conflict.
Kuluwewa - A small tank constructed above the relatively large reservoirs only to trap sediment and not for irrigation purposes. It provides the water necessary for cattle and wild animals.
Tisbambe - It is a fertile land strip found around the settlement area (gangoda) and does not belong to any body. Tree species such as mee, mango, coconut etc. are grown in scattered manner. Mostly this area was used for the sanitary purposes it acts as the resting place of buffaloes. Buffaloes were used as a protection mechanism from wild animals and malaria.
Kiul ela - This is the old natural stream utilized as the common drainage. Tree species such as karanda, mee, mat grass, ikiri, vetakeya etc. and few rare small fish species are also found in water holes along the kiul ela. Most importantly it removes salts and iron in polluted water and improves condition of the drainage water from the paddy tract.
Kattakaduwa - This is a reserved land below the tank bund. It consists of three micro-climatic environments: water hole; wetland; and dry upland, therefore, diverse vegetation is developed. This land phase prevents entering salts and ferric ions into the paddy field. The water hole referred to as 'Yathuruwala' minimizes bund seepage by raising the groundwater table. Villagers plant vetakeya along the toe of the bund to strengthen stability of the bund. It appears to be the village garden, where people utilize various parts of the vegetation for purposes such as fuel wood, medicine, timber, fencing materials, household and farm implements, food, fruits, vegetables etc. [2]. Specifically they harvest row materials from this vegetation for cottage industries.
Figure 3: Essential components of a village tank [2]
5.1.2 Cascade system :
A connected series of tanks are organized within the micro catchments of the dry zone land escape, for storing conveying and utilising water from an ephemeral rivulet (Madduma bandara 1985).
Figure 4: Functional diagram of a cascade system [2]
It is now clearly recognized that the large number (more than 15,000) of small tanks that are distributed across the undulating landscape of the dry zone are not randomly located and distributed as commonly perceived; rather they are found to occur in the form of distinct cascades that are positioned within well defined small watersheds or meso-catchment basins. A cascade of tanks is made up of 4 to 10 individual small tanks, with each tank having its own micro-catchment, but where all of the tanks are situated within a single meso-catchment basin. These meso-catchment basins could be varied in extent from 6 to 10 sq.miles, with a model value of 8 sq. miles in the North Central Province region.
A schematic representation of a typical small tank cascade system with a scale of 1:50,000 is shown in Figure 5 [5]. The main elements to make up a cascade is namely; (a) the water shed boundary of the meso-catchment, (b) the individual micro-catchment boundaries of the small tanks, (c) the main central valley, (d) side valleys, (e) axis of the main valley, and (f) the component small tanks as well as the irrigated rice lands are shown in the same diagram. These small tanks from a series of successive water bodies along small water courses and are called a "cascading system''. The advantage of such a system is that excess water from a reservoir along with the water used in its command area is captured by the next downstream reservoir, and is thus put to use again in the command area of the second reservoir. This water is thus continuously recycled. This system helps to surmount irregularly distributed rainfall, non-availability of large catchment areas and the difficulty of constructing large reservoirs [5].
Figure 5: Schematic representation of small tank cascade [5]
5.2 Sharing outcomes of ecosystem but not raw resources
The outcomes of the ecosystems (paddy, other crops, water etc.), which are needed for the human lives, are sheared among the people in the ecosystem. Ecosystem does not belong or owns to any body. In other words, ecosystem is virtually not divided among people instead outcomes are sheared. Dividing the system for individual ownership beyond a limit will disturb the system. "Bethma" and "Thattumaru" methods of cultivations are adopted to avoid this.
5.3 Bethma method of cultivation :
In water scare situations, villagers get to gather and, an area, which could be cultivated with the limited water is cultivated and the harvest (paddy) is divided among them.
5.4 Thattumaru method :
This is adopted by villages, when the fragmentation of lands makes it difficult to cultivate in small unit. When a villager has a small unit, he opts to forego the cultivation of his unit giving the opportunity another to cultivate a larger unit including his. This makes operational unit more viable. Each farmer gets his turn but not every season.
5.5 Water distribution :
A holistic approach - This was done according to community or group interest.
5.5.1 Bisokotuwa
Biskotuwa is a device used by ancient engineers to control the outflow of water from wewa with considerable heights (10-15m). As shown in figure 6, the Bisokotuwa consists of a rectangular tank connected to the sluice; in almost all the cases the longer side of the rectangle is kept parallel to the bund. Though any evidence regarding the gates of the Bisokotuwa has not been found up to now, speculation about gates, which would have been made out wood and controlled, by a system of levers, shown in figure 2, are mostly accepted in the present among scholars. With these speculated gates the function of the Bisokotuwa could be explained as follows.
When it is required to release water from the wewa, gate A is opened gradually while B is kept open at a particular opening (or gate B would have not existed); then the water level in the Bisokotuwa will come to a height less than that of the water level in the wewa. Then water will flow through the sluice to the out side canal driven by the head of the Bisokotuwa, hence without subjecting the sluice across bund to high pressure as well as velocities created directly from the head of the wewa. When stopping the water release from the wewa, gate A is closed then water inside in the Bisokotuwa will flow through sluice XY (Figure 6) without creating any vacuum condition. In this manner the Bisokotuwa acts as a 'surge' tank, but this is not simply a 'surge' tank; if this was only a surge tank such large cross-sections are already mentioned are not needed.
When water is going out from the wewa, the water first enters the Bisokotuwa the head of water entering it is decreased by allowing it to expand-it is an effective expansion tank. This may probably be reason for laying the Bisokotuwa in such as way that its longer side is parallel to the bund i.e perpendicular to the sluice- the direction of water flow. In the Bisokotuwa the flow (and pressure) of water outgoing from wewas with high heads are controlled by dissipating energy in the water by letting it expand in the Bisokotuwa or rather by letting the water coming to the Bisokotuwa to collide with water inside the Bisokotuwa and thereby releasing its energy by a marvelous non-destructive method. For this to take place properly, the volume of water inside the Bisokotuwa is of critical importance. The large cross section of the Bisokotuwa stated above will fulfill this requirement. In some wewas, for example Urusita wewa at Sooriyawewa, water enters the Bisokotuwa by one conduit (sluice) at the bottom center and goes out by two conduits beginning from the bottom of the opposite wall. With this arrangement the effect of momentum of inlet water on outlet water will be minimized, i.e the outflow will be very calm. Also velocity of water in the outlets will be lower than that of the inlet. Higher velocity in the inlet will increase energy loss; low velocity in the outlets will give a gentle flow, which will be not harmful to the bund as well as to the outgoing canal.
The Bisokotuwa is also used to divert water flows. One such example is seen at an outlet in Parakrama Samudra. In this case, water enters the Bisokotuwa from one side and leaves it from a side perpendicular to it. The forces required to divert the flow of water is obtained from the water itself (inside the Bisokotuwa). Therefore, no effects such as erosion of conduits take place.
Figure 6: Schematic diagram of Bisokotuwa
5.5.2 Karahana :
This provides a more even, simple distribution method when compared with modern methods. Once a certain amount of water released from the wewa each and every plot will approximately get an equal amount of water. No body is needed to regulate water from plot to plot.
Figure 9 -Water dividing devices (Karahana) used in cannels in Puleliya [3]
Figure 10: Water distribution methods [4]
5.6 "Rajakariya"
A community based maintenance methodology for the ecosystem. In this method, about 40 days of each year villages worked for the benefit of the whole community (ecosystem).
5.7 Trans basin canals developed within the ecosystems :
Holistic approach, insitu time tested irregation and water supply projects developed gradually. eg : Jaya Ganga:-The Jayaganga, indeed an ingenious memorial of ancient irrigation, which was undoubtedly designed to serve as a combined irrigation and water supply canal, was not entirely dependent on its feeder reservoir, Kalaweva, for the water it carried. The length of the bund between Kalaweva and Anuradhapura intercepted all the drainage from the high ground to the east which otherwise would have run to waste. Thus the Jayaganga adapted itself to a wide field of irrigation by feeding little village tanks in each subsidiary valley, which lay below its bund. Not infrequently it fed a chain of village tanks down these valleys the tank lower down receiving the overflow from the tank higher up on each chain".
Parakrama Sagaraya:- King Vasabha (65-109) built the Elahera anicut and canal in the first century; nearly three centuries later King Mahasen (276-303) built the Minneriya weva at the tail end of the canal, and probably started its extension beyond Minneriya. Later kings, up to Aggabodhi I, (575-608) completed the extension, and Aggabodhi II (606 - 618) built the Gantalawa weva (Kantale tank) at the tail end. Beyond Kantale Weva, channels led to Tambalakamam bay and the sea at Trincomalee.
This system functioned in the next nearly six centuries, until the reign of Parakrama Bahu (1153-1186), who restored and greatly improved the system. This king raised the Elahera anicut, and strengthened the first 24 miles of the canal from Elahera to Konduruweva, thus creating the second Sea of Parakrama, or Parakrama Sagara, described in the Culavamsa as Koththabadhdhanijjara. This Pali word was translated by Geiger in two different ways which have the same meaning as it should namely "the weir furnished with a reservoir", and "the reservoir whose flood escape was walled up".
5.8 Construction of anicuts :
Construction of anicuts across water flows such as perennial rivers to direct water for canals were also a major part in the ancient water management system. In this case, dams were built obliquely across (or sometimes halfway) the flow ("Redibendilla"). This would have resulted in less silt acumination above the anicut (proper studies has to carried out in the aspects). In some cases there construction were temporary. Any way us all these cases the ancient engineers were very much concern about the ecosystem and the behaviour of the silt. The constructions were done to reduce the accumulation of silt and providing methods to washout the accumulated silt. Also in these constructions the natural flows were not interrupted totally. Proper studies have to be carried out in order to get the ancient knowledge of the construction of anicuts etc without disturbing the ecosystem.
6. Comparison of water management methods :
Comparison of water movement-circulation in a typical indigenous ecosystem and water distribution-drainage system in a typical modern system is illustrated as follows (A proper study has to be carried out for more details).
6.1 Indigenous ecosystem :
Ecosystem perspective ( A perspective, which is based on the sustainable development of human and environment with in the context of Sri Lankan culture.) - water received as rain is stored in the ecosystem in a usable manner then used and drainage is again fed to the system and reuses several times.
Small water cycles through soil: - Water cycle is connected with soil in local vicinity.
Water purification is mainly done by the soil
Irrigated whole land together water conserved, conveyed through the soil or unlined canals
Evaporation (specially from wewa) is facilitated local water cycles as they give rise to convectional rain (Akvehi)
People live along the cascade, this facilitated reuse of water
According to above reasons, water has been reused.
6.2 Modern system :
Storage tank perspective - water gained from rain is stored in tanks, then used and drainage. Water cycle is large connected with sea or other reservoirs, mainly through pipeline, concrete cannels (i.e. water supply and derange).
Water cycle is less connected with the soil in local vicinity
Less water purification by the soil (pollution is also high)
Less water reuse
Today with urbanization connection of water with soil is reduced. Individuals suck water from wells (from water table) and store them in overhead tanks. These will deplete the water table then in most areas the used water is send to sea through drains without much contact with the soil. Therefore the cyclicity of water through soil is disturbed this will give rise for water shortages, in the region. Also for towns water is pumped from rivers and other sources, no reuse as in a wewa in village. Population is clustered in towns unlike in cascade systems.
Today in most development projects canals are constructed for irrigation purposes and separate pipelines are laid for domestic purposes. In ancient systems irrigation as well as other purposes were fulfilled by the same water system, with very much closer to the nature and with very much less pollution [7] ( Mahamankadavala Piyarathana Thera at Eppawala said that about 30 years ago they drank the water from the canals, but now with introduction of chemicals the water system has been polluted and separate waterways are needed for human consumption).
7. Paddy cultivation and water management :
Paddy cultivation is highly connected with water management in Sri Lanka. Almost all the recent irrigation development projects were aimed at supply water for paddy fields. Anyway mentioned here that actually crop water requirement of paddy and the amount of water used for paddy cultivation in conventional paddy cultivation systems (in paddy fields) are different. Water in conventional paddy field systems caters for many requirements of the ecosystem.
Specially wet zone paddy fields acts somewhat as small wewas. Rainfall water, which could have easily drained to sea, is stored in these fields. Also these acts as sponges during heavy rains and are a buffer against erosion. They develop the water table in the vicinity providing water to the ecosystem. Paddy a plant, which could withstand flood condition were grown in these "wewas". Therefore one cannot directly say that water in paddy fields are, a requirement of paddy, and paddy is a crop, which "waste" water. Therefore proper studies has to be carried out on this matters based on ecosystem perspective.
It is worthwhile to coat the following phase from "rice paddy ecosystem" in Bali by Steve Lansing because it would be much helpful in understanding our ancient paddy ecosystem also. "The role of water in rice paddy ecosystem goes for beyond providing water to the roots of paddy plants. By controlling the flow of water into terraced fields, the farmers are able to create pulses in several important cycles. The cycle of wet and dry phases alters soil pH; include a cycle of aerobic and anaerobic conditions in the soil that determines activity of micro-organisms, circulates micro-nutrients; fosters the growth of nitrogen- fixing cyan bacteria; excludes weeds; stabilizes soil temperatures; and over the long term governs formation of a plough pan that prevents nutrients from being leached into the subsoil. On a larger scale the flooding and draining of blocks and terraces also has important effects on pest populations. If farmers on adjacent fields can synchronize their cropping patterns over a sufficiently large area, rice pests are temporarily developed of their habitat and pest populations can be sharply reduced."
8. Evolution and Development of Irrigation Eco-Systems in Ancient Sri Lanka [4]
9. Conclusion / comments :
Water management cannot be identified as an isolated issue. It is highly related to the economic development model- related activities, physical structures-practices and concepts-attitudes in the related culture. A basic introduction about these interrelated categories in modern and ancient contexts is given in this report. Therefore in addressing water related issues one should based on this threefold approach.
(a). Today in the process of solving the water shortage problems one should first study the methods and ways of improving the cyclicity of water through soil separately for each geophysical situations. Conserving water in soil must be considered first i.e. water table should be uplifted. In "hydraulic" water works only rainfall data from isohyets and topography of catchments are taken into consideration. Cyclicity of water through soil (as well as through atmosphere) is ignored. Evaporation from tanks (wewaa) and seepage are taken as losses!
Also instead of net rainfall, rainfall intensity (mm/day) has to be taken in to account [8]. Rainfall intensity has a direct bearing on the distribution of water in soil, therefore by considering this fact proper structures such as Vetiya, wewa has to be constructed in order to store water from rainfalls of varies intensities, in soil in an usable manner i.e. water should be stored at low matric potentials as much as possible ( When water is stored in soil matrix it will be in a negative pressure relative to atmosphere. Surface water and water in water table has zero matric pressure).
In water balancing calculations for a ecosystem (or for the whole country) one cannot say that the total out flow from a ecosystem (or from the whole country through rivers etc) through underground seepage or upland rivers could be used totally, or in other words that one can stop these flows and use that water for other purposes. Because this might disturb and unbalance the ecosystem. Negative out comes of the projects of damming perennial rivers throughout the world are well documented [6]. Principles of indigenous water management do not allow us to treat as total waste. Water balance calculations are done based on ecosystem perspective i.e. by considering the whole ecosystem, its activities functions etc. related to all of its flora & fauna. Also it should be mentioned here that water used by a particular crop or cultivation also should be determined according to this perspective. In this case we may have to redefine the efficiency terms related to these aspects. Proper ecosystem based studies has to be carried out.
(b). As mentioned in section 7, in water management projects related to the paddy cultivation one should based on ecosystem perspective instead on the crop water requirement of the paddy plant.
(c). Cultural practices such as Bethma method should be introduced wherever possible. Also instead of considering only on paddy, ecosystem based chena cultivation and home garden cultivation should be promoted.
(d). The trend is that the decisions such as how the amounts of water that should be allocated for irrigation and hydropower generation are determined by the market price of paddy and electricity. This however distorts, the sustainability of the ecosystem. Therefore a proper national based valuing system should be introduced for paddy, electricity etc in the ecosystem perspective.
(e). Today most of the irrigation projects, which has not shown proper results (E.g. Lunugamvehera, Udawalawe) has been carried out on the basis of a map described as the water recourses development map of Ceylon-1959, which does not identify (give proper value) the ancient structures Wewa, Vetiya etc, which facilitated water storing purification conveying through soil. This map is 1 mile to an inch and 100-foot contours are shown. Also according to Eng. D L O Mendis, the dams of these projects have been situated too much closer to the sea. This will reduced the reuse of water. The proposed Moragahakanda project is also based on this map the projects carried out based on this map and on modern hydraulic-civil engineering perspective do not concern about our ecosystem base perspective which has been time tested for thousands of years.
(f). In Lunugamvehera project about 12 small Wewas, which were with in the storage area, and 30 Wewas in the command area has been demolish. Prior to the project i.e. before the construction of the massive dam all these interconnected wewas had been functioned in a typical ecosystem with the reusing of water [14]. Almost all the necessary food items such as jack coconuts were produced in this system. Now water in the Lunugamvehera tank is not sufficient to feed the estimated command area and farmers are moving in to the direction of cash crops, which require less water such as banana. Therefore now the ecosystem has degraded physically and culturally. In this context, it is strongly proposed to conduct a proper study in the ecosystem perspective to determine the actual water usability (how much of water i.e. gained by rain is used to develop the ecosystem in a sustainable manner), in Lunugamvehera and Udawalawe area prior and after the construction of the dam, the results of this kind of study will provide proper guidelines for future such projects.
(g). In addressing water problems at present most importantly we have to change our minds, attitudes about water and related aspects. Here we would like to quote a part from an article appeared in Scientific American (special report 2005)- "Making every drop count" by Peter H. Gleick. "Part of the difficulty, however, also lies in the prevalence of old ideas among water planners. Addressing the world's basic water problems requires fundamental changes in how we think about water, and such changes are coming slowly. Rather than trying endlessly to find enough water to meet hazy projection in future desires, it is time to find a way to meet our present and future need with the water i.e. already available, while preserving the ecological cycle that are so integral to human well been. This attitude towards water and related aspect is very much closer to the above said attitudes and concepts prevail in Sri Lanka in its culture.
(h). Ecosystems are not owned by anybody, humans are also a part of the ecosystem and they fulfil their requirements arise with in the development model, which is intern, not going against the sustainability of the system. This is cyclic relationship. Unlike in modern situation where development is isolated from ecosystem and development is proceeded apart from the ecosystem and only when ecosystem inhibits the development the concept of "sustainability of the ecosystem" comes to the context.
(i). Water is an integral part of the ecosystem therefore clearly it is also not owned by anybody. Every body could use it to fulfil their requirements with in the sustainable limits of the system. Therefore water cannot be prized and soled in a "free" market. Instead the state could get a tax from water uses according to their amount of water usages. This tax is actually a contribution to the development of the ecosystem. If a person uses water beyond his requirement he has to contribute in a proportional manner i.e. if some body uses water beyond his requirement he does it due to his ability to contribute more to the system in a less selfish manner.
(j). Water is a scarce resource. But unlike a commodity such as fossil-full water is in a cycle and being chemically much stable substance water could be reuse many times within the water cycle without breaking the cycle. In ancient water management this reusing was mainly facilitated by soil and atmosphere. This was almost a natural "reuse". Today the construction of massive dams in odder to block perennial rivers will certainly interrupt the water cycle and hence the ecosystem will have negative results. The concept of the king Parakramabahu the great was to reuse the water received from rain many times as possible before it drain to the sea.
10. References :
1. Brohier R L, The history irrigation and agricultural colonization in Ceylon, The Tamankaduwa District and the Elahera - Minneriya Canal. Academy of Sri Lankan Culture 1998
2. Dharmasena P. B, Towards efficient utilization of surface and ground water resources in food production under small tank system, Proceedings of the workshop on Food security and small tank system in Sri Lanka, 9. Sep.2000. NSF Colombo.
3. Leech E R, "Pull Eliya" Sooriya publication Colombo, 2003.
4. Mendis D L O, Water Heritage of Sri Lanka, Sri Lanka pugwash Group - Colombo 2002
5. Panabokke C. R., The Nature & properties of small tank system of the dry zone and their sustainable production thresholds, Proceedings of the workshop on Food security and small tank system in Sri Lanka, 9. Sep.2000. NSF Colombo
6. Patrick Mccully, Silenced Rivers the ecology and politics of large dams, set books London and New jersey, 1996.
Resource persons :
7. Mahamankadavala Piyarathana Thera, Eppawala
8. Dr. Hadawela,
9. Dr. P. B. Dharmasena, Deputy Director, Field Crops Research Institute, Maha Illukmallama
10. Dr. Ray Wijewardena, Chancellor University of Moratuwa
11. Mr. K. M. P. S. Bandara, Department of Irrigation
12. Mr. Ranjith Rathnayake, Villager at Palleliya
13. Mr. Prabath Vitharana, Dept. of Agrarian Services
14. Mr. Punch Appuhami Villag
From Link - http://www.janathakshan.org/gats_reforms/b/Ecosystem.html
Practical Action (Formerly ITDG)
5, Lionel Edirisinghe Mawatha, Colombo 5, Sri Lanka
Ecosystem based indigenous water management :
1. Background of the report :
The main objective of this report is to give a basic introduction about our indigenous water management. Actually it can be described as ecosystem management. In this regard physical structures, practices as well as cultural aspects (concepts, attitudes economic development model etc) related to this ecosystem management will be briefly out lined.
Indigenous water-ecosystem management cannot be simplified to its physical structures and practices. Presently, the physical structures and practices are taken isolated from the cultural aspects and then the governing economic development model has little meaning. Therefore the intention of this report is to introduce both of these aspects of indigenous water ecosystem management in a holistic manner, and to come up with some guidelines drawn from the "indigenous water ecosystem management" which could be included in a current water policy or in a related matter to solve some of the problems related to water (ecosystem) in today's context.
2. Introduction :
Sri Lankan history is deeply connected with its hydraulic civilization. Today this hydraulic system is erroneously named as an irrigation system. Nevertheless according to most of the renowned authorities (Eng. D L O Mendis, Dr. Ray Wejewardene) in this field this was a sustainable water - soil - flora fauna - human ecosystem, which was mainly based on small tanks (Wewa) in Rajarata and Ruhuna, and basically on anicuts in Mayarata (i.e. mainly the wet zone). The history of this ecosystem leads back to the 4th century B.C. or before. Basawakkulama sometimes known as "Abhayawewa" was identified as the most ancient Wewa, which was done by king Pandukabhaya.
Ancient kings had built major tanks and village tanks simultaneously. For an example king Parakramabahu the great had constructed 165 dams, 3910 canals, 163 major tanks and 2376 village tanks during the last lap of Rajarata [13].
The backbone of this ecosystem was its ability to store the rainfall water within the system for the benefit of the whole system. Unlike in modern irrigation systems, which are focused on supplying the crop water requirement for the root-zone (zone in soil where the roots of trees and plants are spread, water is absorbed to roots in this region), the ancient "hydraulic system" was focused on the water requirement of the entire ecosystem. To fulfil this requirement, various types of structures such as major tanks, small tanks, Vetiyas, Amuna, Vila (lake), Wala (Pond) etc. (Figure 1) and inter connecting canals were constructed very much closer to the nature.
In some areas water from major rivers was conveyed to the major tanks and from there to the small tanks and then to the fields, for an example Elahera-Parakkramasagaraya. In some other areas this was happened totally the other way round, i.e. spilling out water from small-tanks was stored in major tanks. For examples Kuluwewas ( Small surface storage consisting of earth bunds used as a silt trap, flow controller for flood mitigation raising the water table in vicinity.), which are incorporated in most of the ancient systems. In almost all these cases small tanks were constructed in cascade system, which facilitated efficient reuse of water. In this manner these structures were used to store water in the ecosystem (i.e. in the soil) in drought periods and was used in flood mitigation in rainy periods. It should be mentioned here that irrigation was only a part of this hydraulic system.
As mentioned earlier the heart of this ecosystem was the wewa, which gave the lifeblood for the ecosystem. These systems have been sustained for thousands of years. The sustainability of these ecosystems is not only due to there physical structures mentioned earlier. The culture prevailed in these settlements also provided necessary conditions for this sustainability. This culture can assume to be driven not by the self-interest motivated by greed, but by the other motivation like sharing resources equally (even among animals, birds etc.) and the equity of ownership. The statement of Arahat Mahinda states that the king is only the guardian of nature and not the owner. Keeping a Kurulupaluwa (portion of paddy field reserved for birds) would have been a direct outcome of this concept. This culture with that concept proves that, we are just guardians of the nature of the physical structures like wewa to served this ecosystem to function for thousands of years. Actually, in this culture-ecosystem had the in built development model which is suitable for us i.e. our environment & culture. Now we are almost totally apart from this tradition. Today we do not have an idea about our development model and therefore we cannot rehabilitate these ecosystems in a sustainable manner. Anyhow it should be mentioned here that though we cannot go back to the same system today, the guiding principles provide important guidelines for a modern day sustainable water management policy.
3. Indigenous water management :
In the of ancient cultural context water management was not taken as an isolated issue. Hear, the main objective of water management is to optimize the conditions of the proper function of the ecosystem. Water was mainly stored, in the soil and conveyed through the soil and the soil facilitated mainly the water purification process. Water was taken from the soil (from water table) then the used water is again put to the soil, which purify the water and feed the water table for reuse. Water was conserved in the soil (i.e. maintaining the water table). To facilitate this conservation physical structures like cascade wewa system; (in Rajarata) Vetiya (in southern area) Amuna were built according to the geophysical nature of the region. In this manner water receive from the two monsoons was reused several times before it ultimately drained to the sea. Even the inter monsoon rains (Akvehi) would have facilitated this reuse process (i.e. cyclicity). The water evaporated from the wewas help to create convection rains (Akvehi)( Farmers in villagers such as Puleliya, say this by looking at the directional movements of the clouds. When the clouds are almost stationary, they identify the rains as Akvehi) i.e. evaporation from wewas is not a real loss! Also these structures facilitated flood mitigation process in the lower parts of the ecosystem in heavy rainy periods. In this context ecosystem is defined even including the man and the objects and the accessories required by him for his life.
4. Concepts, attitudes related to the sustainable-development model (for ecosystems) :
Buddhism was significantly influenced the Sri Lankan life style (e.g. attitudes, concepts). Some of such prominent Buddhist concepts are listed below.
Greed (Thanha) is the cause for sorrow Dukha. Therefore it should be decreased( Buddhist Sutrapitake - Load Buddha) .
Happiness is the most impotent wealth. ("Santhutti paramang Dhanang") ( Buddhist Sutrapitake - Load Buddha)
Equity of ownership
Attitude towards nature - nature does not belong to anybody. We are only a part of it and we can use it in a sustainable manner for our survival without much disturbing much to the other partners. Statement of Arahant Mahinda.
Less selfish, holistic community based approach to optimise the ecosystem.
Holistic approach towards nature [9].
5. Structural features and practices of this ecosystem :
5.1 Rain water trapping structures :
In the ancient water management, amount of rainfall (nowadays measured in "mm") and the intensity of rainfall (nowadays measured in "mm/day") were deliberated. Small structures like Vetiya captures the water from very low intensity rainfall. Small tanks capture the water from much higher rainfalls and major tanks capture water from even higher rainfalls [5].
5.1.1 Wewa :
There are about 12,000 small tanks and anicuts found in Sri Lanka and these tanks and anicuts irrigate an extent of about 185,000ha. This is 35% of total irrigable area in the country. Small irrigation schemes produce 191,000mt annually accounting for 20% of the national irrigated rice production (Agricultural implementation programme 1994 - 95). Following are the essential components of a village tank (figure 3).
Gasgommana - It is the upstream of the land strip located above the tank bed and water is accumulated in Gasgommana only when the tanks spill out. Naturally grown large trees such as Kumbuk, Nabada, Maila, Damba etc. and climbers such as Kaila, Elipaththa, Kakukeliya, kalawel, bokalawel etc. are subsisted in this area. The gasgommana acts as a wind barrier and at the same time it helps to reduce evaporation from the tank and to lower the water temperature. It gets closer to the bund from either side where roots of large trees make water cages creating breeding and living places for some fish species. This strip of trees demarcates the territory between human and wild animals.
Perahana - It is the meadow developed under gasgommana and filters the sediment flow coming from the upstream chena lands.
Iswetiya or potawetiya - It is the constructed soil ridge in the upstream of the tank at either side of the tank bund to prevent entering the eroded soil from upper land slopes.
Godawala - A manmade water hole to trap sediment and it provides water to wild animals. This might be a strategy used to evade man-animal conflict.
Kuluwewa - A small tank constructed above the relatively large reservoirs only to trap sediment and not for irrigation purposes. It provides the water necessary for cattle and wild animals.
Tisbambe - It is a fertile land strip found around the settlement area (gangoda) and does not belong to any body. Tree species such as mee, mango, coconut etc. are grown in scattered manner. Mostly this area was used for the sanitary purposes it acts as the resting place of buffaloes. Buffaloes were used as a protection mechanism from wild animals and malaria.
Kiul ela - This is the old natural stream utilized as the common drainage. Tree species such as karanda, mee, mat grass, ikiri, vetakeya etc. and few rare small fish species are also found in water holes along the kiul ela. Most importantly it removes salts and iron in polluted water and improves condition of the drainage water from the paddy tract.
Kattakaduwa - This is a reserved land below the tank bund. It consists of three micro-climatic environments: water hole; wetland; and dry upland, therefore, diverse vegetation is developed. This land phase prevents entering salts and ferric ions into the paddy field. The water hole referred to as 'Yathuruwala' minimizes bund seepage by raising the groundwater table. Villagers plant vetakeya along the toe of the bund to strengthen stability of the bund. It appears to be the village garden, where people utilize various parts of the vegetation for purposes such as fuel wood, medicine, timber, fencing materials, household and farm implements, food, fruits, vegetables etc. [2]. Specifically they harvest row materials from this vegetation for cottage industries.
Figure 3: Essential components of a village tank [2]
5.1.2 Cascade system :
A connected series of tanks are organized within the micro catchments of the dry zone land escape, for storing conveying and utilising water from an ephemeral rivulet (Madduma bandara 1985).
Figure 4: Functional diagram of a cascade system [2]
It is now clearly recognized that the large number (more than 15,000) of small tanks that are distributed across the undulating landscape of the dry zone are not randomly located and distributed as commonly perceived; rather they are found to occur in the form of distinct cascades that are positioned within well defined small watersheds or meso-catchment basins. A cascade of tanks is made up of 4 to 10 individual small tanks, with each tank having its own micro-catchment, but where all of the tanks are situated within a single meso-catchment basin. These meso-catchment basins could be varied in extent from 6 to 10 sq.miles, with a model value of 8 sq. miles in the North Central Province region.
A schematic representation of a typical small tank cascade system with a scale of 1:50,000 is shown in Figure 5 [5]. The main elements to make up a cascade is namely; (a) the water shed boundary of the meso-catchment, (b) the individual micro-catchment boundaries of the small tanks, (c) the main central valley, (d) side valleys, (e) axis of the main valley, and (f) the component small tanks as well as the irrigated rice lands are shown in the same diagram. These small tanks from a series of successive water bodies along small water courses and are called a "cascading system''. The advantage of such a system is that excess water from a reservoir along with the water used in its command area is captured by the next downstream reservoir, and is thus put to use again in the command area of the second reservoir. This water is thus continuously recycled. This system helps to surmount irregularly distributed rainfall, non-availability of large catchment areas and the difficulty of constructing large reservoirs [5].
Figure 5: Schematic representation of small tank cascade [5]
5.2 Sharing outcomes of ecosystem but not raw resources
The outcomes of the ecosystems (paddy, other crops, water etc.), which are needed for the human lives, are sheared among the people in the ecosystem. Ecosystem does not belong or owns to any body. In other words, ecosystem is virtually not divided among people instead outcomes are sheared. Dividing the system for individual ownership beyond a limit will disturb the system. "Bethma" and "Thattumaru" methods of cultivations are adopted to avoid this.
5.3 Bethma method of cultivation :
In water scare situations, villagers get to gather and, an area, which could be cultivated with the limited water is cultivated and the harvest (paddy) is divided among them.
5.4 Thattumaru method :
This is adopted by villages, when the fragmentation of lands makes it difficult to cultivate in small unit. When a villager has a small unit, he opts to forego the cultivation of his unit giving the opportunity another to cultivate a larger unit including his. This makes operational unit more viable. Each farmer gets his turn but not every season.
5.5 Water distribution :
A holistic approach - This was done according to community or group interest.
5.5.1 Bisokotuwa
Biskotuwa is a device used by ancient engineers to control the outflow of water from wewa with considerable heights (10-15m). As shown in figure 6, the Bisokotuwa consists of a rectangular tank connected to the sluice; in almost all the cases the longer side of the rectangle is kept parallel to the bund. Though any evidence regarding the gates of the Bisokotuwa has not been found up to now, speculation about gates, which would have been made out wood and controlled, by a system of levers, shown in figure 2, are mostly accepted in the present among scholars. With these speculated gates the function of the Bisokotuwa could be explained as follows.
When it is required to release water from the wewa, gate A is opened gradually while B is kept open at a particular opening (or gate B would have not existed); then the water level in the Bisokotuwa will come to a height less than that of the water level in the wewa. Then water will flow through the sluice to the out side canal driven by the head of the Bisokotuwa, hence without subjecting the sluice across bund to high pressure as well as velocities created directly from the head of the wewa. When stopping the water release from the wewa, gate A is closed then water inside in the Bisokotuwa will flow through sluice XY (Figure 6) without creating any vacuum condition. In this manner the Bisokotuwa acts as a 'surge' tank, but this is not simply a 'surge' tank; if this was only a surge tank such large cross-sections are already mentioned are not needed.
When water is going out from the wewa, the water first enters the Bisokotuwa the head of water entering it is decreased by allowing it to expand-it is an effective expansion tank. This may probably be reason for laying the Bisokotuwa in such as way that its longer side is parallel to the bund i.e perpendicular to the sluice- the direction of water flow. In the Bisokotuwa the flow (and pressure) of water outgoing from wewas with high heads are controlled by dissipating energy in the water by letting it expand in the Bisokotuwa or rather by letting the water coming to the Bisokotuwa to collide with water inside the Bisokotuwa and thereby releasing its energy by a marvelous non-destructive method. For this to take place properly, the volume of water inside the Bisokotuwa is of critical importance. The large cross section of the Bisokotuwa stated above will fulfill this requirement. In some wewas, for example Urusita wewa at Sooriyawewa, water enters the Bisokotuwa by one conduit (sluice) at the bottom center and goes out by two conduits beginning from the bottom of the opposite wall. With this arrangement the effect of momentum of inlet water on outlet water will be minimized, i.e the outflow will be very calm. Also velocity of water in the outlets will be lower than that of the inlet. Higher velocity in the inlet will increase energy loss; low velocity in the outlets will give a gentle flow, which will be not harmful to the bund as well as to the outgoing canal.
The Bisokotuwa is also used to divert water flows. One such example is seen at an outlet in Parakrama Samudra. In this case, water enters the Bisokotuwa from one side and leaves it from a side perpendicular to it. The forces required to divert the flow of water is obtained from the water itself (inside the Bisokotuwa). Therefore, no effects such as erosion of conduits take place.
Figure 6: Schematic diagram of Bisokotuwa
5.5.2 Karahana :
This provides a more even, simple distribution method when compared with modern methods. Once a certain amount of water released from the wewa each and every plot will approximately get an equal amount of water. No body is needed to regulate water from plot to plot.
Figure 9 -Water dividing devices (Karahana) used in cannels in Puleliya [3]
Figure 10: Water distribution methods [4]
5.6 "Rajakariya"
A community based maintenance methodology for the ecosystem. In this method, about 40 days of each year villages worked for the benefit of the whole community (ecosystem).
5.7 Trans basin canals developed within the ecosystems :
Holistic approach, insitu time tested irregation and water supply projects developed gradually. eg : Jaya Ganga:-The Jayaganga, indeed an ingenious memorial of ancient irrigation, which was undoubtedly designed to serve as a combined irrigation and water supply canal, was not entirely dependent on its feeder reservoir, Kalaweva, for the water it carried. The length of the bund between Kalaweva and Anuradhapura intercepted all the drainage from the high ground to the east which otherwise would have run to waste. Thus the Jayaganga adapted itself to a wide field of irrigation by feeding little village tanks in each subsidiary valley, which lay below its bund. Not infrequently it fed a chain of village tanks down these valleys the tank lower down receiving the overflow from the tank higher up on each chain".
Parakrama Sagaraya:- King Vasabha (65-109) built the Elahera anicut and canal in the first century; nearly three centuries later King Mahasen (276-303) built the Minneriya weva at the tail end of the canal, and probably started its extension beyond Minneriya. Later kings, up to Aggabodhi I, (575-608) completed the extension, and Aggabodhi II (606 - 618) built the Gantalawa weva (Kantale tank) at the tail end. Beyond Kantale Weva, channels led to Tambalakamam bay and the sea at Trincomalee.
This system functioned in the next nearly six centuries, until the reign of Parakrama Bahu (1153-1186), who restored and greatly improved the system. This king raised the Elahera anicut, and strengthened the first 24 miles of the canal from Elahera to Konduruweva, thus creating the second Sea of Parakrama, or Parakrama Sagara, described in the Culavamsa as Koththabadhdhanijjara. This Pali word was translated by Geiger in two different ways which have the same meaning as it should namely "the weir furnished with a reservoir", and "the reservoir whose flood escape was walled up".
5.8 Construction of anicuts :
Construction of anicuts across water flows such as perennial rivers to direct water for canals were also a major part in the ancient water management system. In this case, dams were built obliquely across (or sometimes halfway) the flow ("Redibendilla"). This would have resulted in less silt acumination above the anicut (proper studies has to carried out in the aspects). In some cases there construction were temporary. Any way us all these cases the ancient engineers were very much concern about the ecosystem and the behaviour of the silt. The constructions were done to reduce the accumulation of silt and providing methods to washout the accumulated silt. Also in these constructions the natural flows were not interrupted totally. Proper studies have to be carried out in order to get the ancient knowledge of the construction of anicuts etc without disturbing the ecosystem.
6. Comparison of water management methods :
Comparison of water movement-circulation in a typical indigenous ecosystem and water distribution-drainage system in a typical modern system is illustrated as follows (A proper study has to be carried out for more details).
6.1 Indigenous ecosystem :
Ecosystem perspective ( A perspective, which is based on the sustainable development of human and environment with in the context of Sri Lankan culture.) - water received as rain is stored in the ecosystem in a usable manner then used and drainage is again fed to the system and reuses several times.
Small water cycles through soil: - Water cycle is connected with soil in local vicinity.
Water purification is mainly done by the soil
Irrigated whole land together water conserved, conveyed through the soil or unlined canals
Evaporation (specially from wewa) is facilitated local water cycles as they give rise to convectional rain (Akvehi)
People live along the cascade, this facilitated reuse of water
According to above reasons, water has been reused.
6.2 Modern system :
Storage tank perspective - water gained from rain is stored in tanks, then used and drainage. Water cycle is large connected with sea or other reservoirs, mainly through pipeline, concrete cannels (i.e. water supply and derange).
Water cycle is less connected with the soil in local vicinity
Less water purification by the soil (pollution is also high)
Less water reuse
Today with urbanization connection of water with soil is reduced. Individuals suck water from wells (from water table) and store them in overhead tanks. These will deplete the water table then in most areas the used water is send to sea through drains without much contact with the soil. Therefore the cyclicity of water through soil is disturbed this will give rise for water shortages, in the region. Also for towns water is pumped from rivers and other sources, no reuse as in a wewa in village. Population is clustered in towns unlike in cascade systems.
Today in most development projects canals are constructed for irrigation purposes and separate pipelines are laid for domestic purposes. In ancient systems irrigation as well as other purposes were fulfilled by the same water system, with very much closer to the nature and with very much less pollution [7] ( Mahamankadavala Piyarathana Thera at Eppawala said that about 30 years ago they drank the water from the canals, but now with introduction of chemicals the water system has been polluted and separate waterways are needed for human consumption).
7. Paddy cultivation and water management :
Paddy cultivation is highly connected with water management in Sri Lanka. Almost all the recent irrigation development projects were aimed at supply water for paddy fields. Anyway mentioned here that actually crop water requirement of paddy and the amount of water used for paddy cultivation in conventional paddy cultivation systems (in paddy fields) are different. Water in conventional paddy field systems caters for many requirements of the ecosystem.
Specially wet zone paddy fields acts somewhat as small wewas. Rainfall water, which could have easily drained to sea, is stored in these fields. Also these acts as sponges during heavy rains and are a buffer against erosion. They develop the water table in the vicinity providing water to the ecosystem. Paddy a plant, which could withstand flood condition were grown in these "wewas". Therefore one cannot directly say that water in paddy fields are, a requirement of paddy, and paddy is a crop, which "waste" water. Therefore proper studies has to be carried out on this matters based on ecosystem perspective.
It is worthwhile to coat the following phase from "rice paddy ecosystem" in Bali by Steve Lansing because it would be much helpful in understanding our ancient paddy ecosystem also. "The role of water in rice paddy ecosystem goes for beyond providing water to the roots of paddy plants. By controlling the flow of water into terraced fields, the farmers are able to create pulses in several important cycles. The cycle of wet and dry phases alters soil pH; include a cycle of aerobic and anaerobic conditions in the soil that determines activity of micro-organisms, circulates micro-nutrients; fosters the growth of nitrogen- fixing cyan bacteria; excludes weeds; stabilizes soil temperatures; and over the long term governs formation of a plough pan that prevents nutrients from being leached into the subsoil. On a larger scale the flooding and draining of blocks and terraces also has important effects on pest populations. If farmers on adjacent fields can synchronize their cropping patterns over a sufficiently large area, rice pests are temporarily developed of their habitat and pest populations can be sharply reduced."
8. Evolution and Development of Irrigation Eco-Systems in Ancient Sri Lanka [4]
9. Conclusion / comments :
Water management cannot be identified as an isolated issue. It is highly related to the economic development model- related activities, physical structures-practices and concepts-attitudes in the related culture. A basic introduction about these interrelated categories in modern and ancient contexts is given in this report. Therefore in addressing water related issues one should based on this threefold approach.
(a). Today in the process of solving the water shortage problems one should first study the methods and ways of improving the cyclicity of water through soil separately for each geophysical situations. Conserving water in soil must be considered first i.e. water table should be uplifted. In "hydraulic" water works only rainfall data from isohyets and topography of catchments are taken into consideration. Cyclicity of water through soil (as well as through atmosphere) is ignored. Evaporation from tanks (wewaa) and seepage are taken as losses!
Also instead of net rainfall, rainfall intensity (mm/day) has to be taken in to account [8]. Rainfall intensity has a direct bearing on the distribution of water in soil, therefore by considering this fact proper structures such as Vetiya, wewa has to be constructed in order to store water from rainfalls of varies intensities, in soil in an usable manner i.e. water should be stored at low matric potentials as much as possible ( When water is stored in soil matrix it will be in a negative pressure relative to atmosphere. Surface water and water in water table has zero matric pressure).
In water balancing calculations for a ecosystem (or for the whole country) one cannot say that the total out flow from a ecosystem (or from the whole country through rivers etc) through underground seepage or upland rivers could be used totally, or in other words that one can stop these flows and use that water for other purposes. Because this might disturb and unbalance the ecosystem. Negative out comes of the projects of damming perennial rivers throughout the world are well documented [6]. Principles of indigenous water management do not allow us to treat as total waste. Water balance calculations are done based on ecosystem perspective i.e. by considering the whole ecosystem, its activities functions etc. related to all of its flora & fauna. Also it should be mentioned here that water used by a particular crop or cultivation also should be determined according to this perspective. In this case we may have to redefine the efficiency terms related to these aspects. Proper ecosystem based studies has to be carried out.
(b). As mentioned in section 7, in water management projects related to the paddy cultivation one should based on ecosystem perspective instead on the crop water requirement of the paddy plant.
(c). Cultural practices such as Bethma method should be introduced wherever possible. Also instead of considering only on paddy, ecosystem based chena cultivation and home garden cultivation should be promoted.
(d). The trend is that the decisions such as how the amounts of water that should be allocated for irrigation and hydropower generation are determined by the market price of paddy and electricity. This however distorts, the sustainability of the ecosystem. Therefore a proper national based valuing system should be introduced for paddy, electricity etc in the ecosystem perspective.
(e). Today most of the irrigation projects, which has not shown proper results (E.g. Lunugamvehera, Udawalawe) has been carried out on the basis of a map described as the water recourses development map of Ceylon-1959, which does not identify (give proper value) the ancient structures Wewa, Vetiya etc, which facilitated water storing purification conveying through soil. This map is 1 mile to an inch and 100-foot contours are shown. Also according to Eng. D L O Mendis, the dams of these projects have been situated too much closer to the sea. This will reduced the reuse of water. The proposed Moragahakanda project is also based on this map the projects carried out based on this map and on modern hydraulic-civil engineering perspective do not concern about our ecosystem base perspective which has been time tested for thousands of years.
(f). In Lunugamvehera project about 12 small Wewas, which were with in the storage area, and 30 Wewas in the command area has been demolish. Prior to the project i.e. before the construction of the massive dam all these interconnected wewas had been functioned in a typical ecosystem with the reusing of water [14]. Almost all the necessary food items such as jack coconuts were produced in this system. Now water in the Lunugamvehera tank is not sufficient to feed the estimated command area and farmers are moving in to the direction of cash crops, which require less water such as banana. Therefore now the ecosystem has degraded physically and culturally. In this context, it is strongly proposed to conduct a proper study in the ecosystem perspective to determine the actual water usability (how much of water i.e. gained by rain is used to develop the ecosystem in a sustainable manner), in Lunugamvehera and Udawalawe area prior and after the construction of the dam, the results of this kind of study will provide proper guidelines for future such projects.
(g). In addressing water problems at present most importantly we have to change our minds, attitudes about water and related aspects. Here we would like to quote a part from an article appeared in Scientific American (special report 2005)- "Making every drop count" by Peter H. Gleick. "Part of the difficulty, however, also lies in the prevalence of old ideas among water planners. Addressing the world's basic water problems requires fundamental changes in how we think about water, and such changes are coming slowly. Rather than trying endlessly to find enough water to meet hazy projection in future desires, it is time to find a way to meet our present and future need with the water i.e. already available, while preserving the ecological cycle that are so integral to human well been. This attitude towards water and related aspect is very much closer to the above said attitudes and concepts prevail in Sri Lanka in its culture.
(h). Ecosystems are not owned by anybody, humans are also a part of the ecosystem and they fulfil their requirements arise with in the development model, which is intern, not going against the sustainability of the system. This is cyclic relationship. Unlike in modern situation where development is isolated from ecosystem and development is proceeded apart from the ecosystem and only when ecosystem inhibits the development the concept of "sustainability of the ecosystem" comes to the context.
(i). Water is an integral part of the ecosystem therefore clearly it is also not owned by anybody. Every body could use it to fulfil their requirements with in the sustainable limits of the system. Therefore water cannot be prized and soled in a "free" market. Instead the state could get a tax from water uses according to their amount of water usages. This tax is actually a contribution to the development of the ecosystem. If a person uses water beyond his requirement he has to contribute in a proportional manner i.e. if some body uses water beyond his requirement he does it due to his ability to contribute more to the system in a less selfish manner.
(j). Water is a scarce resource. But unlike a commodity such as fossil-full water is in a cycle and being chemically much stable substance water could be reuse many times within the water cycle without breaking the cycle. In ancient water management this reusing was mainly facilitated by soil and atmosphere. This was almost a natural "reuse". Today the construction of massive dams in odder to block perennial rivers will certainly interrupt the water cycle and hence the ecosystem will have negative results. The concept of the king Parakramabahu the great was to reuse the water received from rain many times as possible before it drain to the sea.
10. References :
1. Brohier R L, The history irrigation and agricultural colonization in Ceylon, The Tamankaduwa District and the Elahera - Minneriya Canal. Academy of Sri Lankan Culture 1998
2. Dharmasena P. B, Towards efficient utilization of surface and ground water resources in food production under small tank system, Proceedings of the workshop on Food security and small tank system in Sri Lanka, 9. Sep.2000. NSF Colombo.
3. Leech E R, "Pull Eliya" Sooriya publication Colombo, 2003.
4. Mendis D L O, Water Heritage of Sri Lanka, Sri Lanka pugwash Group - Colombo 2002
5. Panabokke C. R., The Nature & properties of small tank system of the dry zone and their sustainable production thresholds, Proceedings of the workshop on Food security and small tank system in Sri Lanka, 9. Sep.2000. NSF Colombo
6. Patrick Mccully, Silenced Rivers the ecology and politics of large dams, set books London and New jersey, 1996.
Resource persons :
7. Mahamankadavala Piyarathana Thera, Eppawala
8. Dr. Hadawela,
9. Dr. P. B. Dharmasena, Deputy Director, Field Crops Research Institute, Maha Illukmallama
10. Dr. Ray Wijewardena, Chancellor University of Moratuwa
11. Mr. K. M. P. S. Bandara, Department of Irrigation
12. Mr. Ranjith Rathnayake, Villager at Palleliya
13. Mr. Prabath Vitharana, Dept. of Agrarian Services
14. Mr. Punch Appuhami Villag
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