Dry Zone Tank-Village: A System for Reducing the Impact of Drought

2009. Proc. of the Workshop on Role of Community in Adaptation to the Climate Change Crisis. (Eds) Gunaratne, L.H.P., W.A.P. Weearakkody, K.S. Hemachandra and P.Y. Yapa, Swedish Cooperative Centre and PGIA, Peradeniya. p. 125-136. Dry Zone Tank-Village: A System for Reducing the Impact of Drought P.B. Dharmasena History and cultural heritage of Sri Lanka extends over a period of more than 5000 years. The great King Ravana ruled the land of Lanka, which covered also part of India, around 3000 BC as mentioned in the popular Indian epic Ramayana (The Epic of Lord Rama), thought to have been written in 500 BC. The capital of the Asura King Ravana is said in the epic Ramayana to be situated in Anuradhapura. The invasion of Lanka by Vijaya through the Princess Kuweni (Princess of land) occurred in 600 BC. The Princess Kuweni ruled the area Chalaka (western region), which was one of the ten divisions at that time. According to Warga Poornika, an unknown historical record these ten divisions were: Kewesastha (Northern region); Upulwangiri (Dambulla area); Rakungiri (Ritigala area); Neelagiri (Manewa area); Kawastha Labba (Habarana area); Dhumaka kaddira (Kalaoya area); Chalaka (Thammenna area); Indra (Eastern region); Agni (South-west region) and Mahagiri (Samanala region). Over the course of history, large number of communities developed their own culture and lifestyle that are intricately tied to nature and the local ecosystems. Indigenous knowledge is one of the products remained for centuries, firmly inbuilt into the belief systems, myths and folklore of society; and it expresses the local solutions. It makes decisions regarding the use of resources and environmental conservation. Incorrect decisions made in recent development process and their consequences can be interpreted easily as a result of ignoring the local knowledge. This knowledge helped avoid the impact of natural disasters. One aspect showing the importance of indigenous knowledge is agricultural methodology. It constitutes an environmental management system that is largely community led. Knowledge on various practices and technologies has been built up over time. They could find best practices on how grains are stored for consumption as well as for seed requirement without any quality deterioration. Beliefs are synthesized with disasters, worries, failures and successes experienced through generations. They protected forest, watersheds, medicinal species and various pious places and materials. Simple tools and implements were developed to deal with many operations that the community had to perform in their daily life. Religious festivals were organized with different objectives but led to strengthen their social solidity and self motivation. Materials had been identified from natural environment to be utilized for housing construction, basketry and other craft industries. Indigenous agriculture is based on more realistic principles. People observed natural phenomena operating around them and studied how it could be manipulated for their needs. They could see the forest, its anatomy, association of different species for coexistence, regeneration after fire, spatial variations etc. The farming system, which includes chena, paddy and home garden cultivation has been evolved with interaction of man with the environment and developed in harmony with natural ecosystems. Their experience and observations on rainfall pattern, wind, temperature, humidity and soil behaviours have used to adjust their cultivation activities. When they found that some of the tragedies they faced in farming as reasons beyond their control, they appealed the support from the religion and spiritual and cosmic influences. Most important fact they realized on top of others that without giving due respect to the resources using for farming they could not expect the sustainability of their food sources. The land use associated with tank cascades demonstrated a profound knowledge of resource management in a challenging environment essentially transformed from natural ecosystems into agro-ecosystems. Integrated land and water resources management in ancient times is reflected in the zonation of land use within the micro-catchments. The tanks and the paddy fields occupied the valleys, where Low Humic Gley soils with poor drainage had limited use other than for bunded paddy cultivation. Ridge summits, often strewn with rock outcrops and inselbergs, were converted into works of art and places of worship and spiritual retreat. The influence of Buddhism led to the establishment of sanctuaries early in history and the enduring protection of wildlife unusual in many parts of the world. The farming system is characterized by its three-fold pattern of land use. Rice, the Sri Lankan's staple food crop is grown in the irrigable lowland mainly in maha season and perhaps in yala season depending upon the availability of water in the tank. The village hamlet (Gan-goda) is in either side of the rice grown area (Wel-yaya) usually below the tank and cultivated with perennial crops and vegetables. Due to the influence of tank water and lower elevation, where the soil is imperfectly drained, most of the fruit crops such as mango, jak etc., coconut and some vegetables are easily grown in the home garden. `Chena' the third component, is the oldest farming practice of dry zone villagers in the upland using direct rainfall. Further, to the three-fold pattern cattle and buffalo play a significant role in the traditional farming system. Land ownership of the paddy tract is distributed among villagers in a manner so that each farmer could have similar access and right to the irrigation water. Decision making on cultivation of a portion of paddy tract sharing proportionately among farmers in water shortage seasons (bethma cultivation) is a good example of their unity. Cultivation of the upper tank bed area (thavulu govithena) during extremely dry seasons taking adequate precaution to prevent sediment flow into tank is an example showing their cultivation wisdom. The indigenous knowledge, which has been evolved for centuries in harmony with traditional farming and its culture is not just a techno-physiological process. It is a combination of wisdoms sharpened by bitter and painful experience they had, affected by environmental and Cosmo-vision phenomena and derived on religious and spiritual background. Specialty of the indigenous knowledge is therefore, that it is always in accordance with the rules, principles and phenomena of the nature. This environmental compatibility and the sustainability of the human system is the ultimate result of facing crudity of climatic changes and tolerating the natural momentums (disasters) occurred from time to time. The early hydraulic societies thrived on small irrigation systems with unique assemblages of land uses and agricultural attributes. Possibly these systems evolved from early rain-fed shifting agriculture into small scale irrigation that, in turn, led to major systems. The sedentary way of life facilitated by this hydraulic base led to land tenure, property inheritance, and social organizations that persisted for centuries. Community leadership patterns had to be strong and effective with increasing size and complexity of irrigation systems. These conditions eventually led to centralized authority representing a form of oriental despotism. Conveyance of irrigation water over long distances needed efficient control over distribution and allocation between the top and tail-ends of the system. Smooth functioning of all hydraulic structures required efficient maintenance. Irrigation depending on micro-catchments required careful watershed management to reduce siltation and ensure catchment water yields. The land and water use system that developed over centuries to satisfy these requirements has been described as a ‘cascading system’. Organization of small tanks into a cascading sequence within micro-catchments allowed grater efficiencies in water use. Drainage from the paddy fields in the upper part of the cascade flowed into a downstream tank for reuse in the paddy fields below. The system fully expressed the well known dictum by the King Parakramabahu (1153 - 1186 AD) that “not a single drop of water received from rain should be allowed to escape into the sea without being utilized for human benefit”. The ancient hydraulic civilization of the dry zone disappeared after the 12th century AD. Climatic change, malaria, depletion of soil fertility, foreign invasions and famine are some of the reasons cited. As stated by Prof. Paranawithana, the breakdown of the efficient irrigation management system may have resulted from annihilation of the kulinas (the dry zone nobility who possessed irrigation expertise) by invading South Indian forces. In the past two decades, a growing set of evidence has indicated a strong relationship between indigenous knowledge and sustainable development. Large populations in developing countries owe their survival to the time-tested application and use of indigenous knowledge in environmental protection and reduction of the impacts of natural disasters. At present, indigenous knowledge disappears rapidly from these communities accommodating modern practices with advancement of science. However, as once stated by Robert Chambers, “Systems of knowledge are many. Among these, modern science is only one, though the most powerful and universal. Rural people’s knowledge is in contrast ‘situated’, differing both by locality and by group and individual, and differing in its modes of experimenting and learning: different people know different things in different places, and learn new things in different ways.” A distinct drought occurs in the dry zone from June to September in any year. It is rare to ob serve any productive rain during this period. All forests and permanent crops depend on soil moisture and groundwater. Whole vegetation dries off leaving some natural flora, which tolerate the dry condition. Groundwater depletes gradually. Wildlife roams searching for any water source. Many natural streams dry out. People and animals have become accustomed to this annual drought. The dry zone communities gathered and stored grains, dried vegetables, dry fish and meat etc. in the past to consume in dry periods. They saved water in tanks if the drought is mild. If the drought continued they dug holes in tank beds and river turns. This traditional life system, when affected with present trends of living, seeks for external support failing to face even a short drought. Many perennials established in rainy season die off due to water shortage during the drought. Thus, it is very rare to observe a canopy cover in home gardens located on ridges, where there is no influence of groundwater. The community was protected from environmental disasters due to the sustainability of tank-village system. The ability of tolerating short term drought was well established in this traditional community. Further, the cultivation pattern was scheduled according to the rainfall pattern even in a normal year to reduce the risk. It was always meant to assure the food security. The people were accustomed to a three-fold farming system farming chena with rainfall, cultivating paddy with tank water and managing home gardens with fruits and vegetables. They resort more to chena and plant grain crops on burnt land if they receive more rains during September (known as binara kaluwa). They do not expect much rains after December. This leads to make decisions to confine the paddy farming to the marshy portion (agal pela) of the paddy tract. If the inter-monsoonal rains delay, they practice dry sowing (kekulama) expecting more rains in subsequent months. This decision enables them to cultivate the entire paddy tract. Irrespective of the rainfall pattern they cultivate vegetables successfully around their dwelling as the hamlet land portion is moist for a long time. If the monsoonal rains continue beyond December, the chena crops could be affected with excess moisture, but they keep more hopes on a second cultivation in the paddy tract with tank water. The whole cropping pattern for the maha season could be decided according to the rains received during September from binara kaluwa. This phenomenon could be confirmed when the rainfall data observed during last hundred years at Mahailluppallama was analyzed (Fig. 1). There are few other factors aggravating the drought. One is inability of the eroded soil to hold water. Thus, soil dries soon after rainy season and crop dies. This is more distinct in low rainfall seasons. Another is that the amount of rainwater, which contributes to groundwater decreases with increasing the land extent cleared for cultivation. Then the drought effect becomes more distinct due to decline of groundwater resource. Among other factors aggravating drought effect, rise of soil temperature, low humidity in the atmosphere, high evaporative demand causing rapid drying of soil are the most prominent. The factor, which needs urgent attention is the rapid depletion of groundwater due to over-abstraction for cultivation advancing the commencement of drought. In brief the drought effect aggravates due to absence of preparedness, removal of forest, soil erosion and indiscriminate use of groundwater. Rainfall from October to February (mm) September Rainfall Vs. October – February Rainfalls (Mahailluppallama 1905 – 2003) 1000 950 900 850 800 750 700 650 600 0 50 100 150 200 250 300 350 Rainfall in September (mm) Fig. 1. Forecasting maha rains from September rainfall If the drought continues, it converts into a famine. The drought or the famine is mostly considered a natural disaster. The severe drought occurred in America during 1983 dropped the annual grain production by 20 million tons. This was compensated through Govt. intervention. Famine occurred in Ethiopia during 1984 did not come to an end in the same way. It dropped the annual grain production only by 2 million tons. The Government had nothing to do. No one knows the exact number of deaths. It might be more than 400,000. This comparison clearly explains the fact that ‘there is no famine, where there is no poor nation or a Government’. Famine is really a socio-economic process. The victims of a community are the poorest or the people who are at marginal subsistence level. They get affected once they fail to maintain a sustainable living. The process continues to a level, at which a person can not find food for his survival. Consequence of drought is very clear. It affects all who are not prepared to face it. Since 1,800, the Ethiopians experienced about 20 severe droughts. If it happens tomorrow they are not prepared to face it. Simply all who fail to achieve a sustainable development, would become victims of drought. Specialty of the traditional communities in facing a drought is that they face it collectively rather seeking food individually in a selfish manner. They attempted to find solution and gathered knowledge than ignoring as a natural event. Thus, the knowledge continued to be refined and advanced. One part of the knowledge developed is how they could be adjusted by themselves to withstand the drought. A study conducted with Sudan people affected by drought reveals that the process continues in three steps. In the first step people get adjusted to live at subsistence level. At the second stage they attempt to maintain subsistence living by selling resources and borrowing food and money. Third is a non-coping stage where they have to starve and depend on charity. However, famine disasters can not be addressed through such a process and only the consequence can be delayed. The chena cultivation is a type of mixed farming. Loss of one crop can be compensated with the other crops. They observe the fertility of land carefully and change the crops to suit the productivity level of the land as shown below. Type of Chena Nawadeli hena (after burning the forest) Athdandu hena (after burning the secondary vegetation) Landa/ hiri landa (prepared from shrub land) Kanathu/ piti (lands abandoned due to low fertility) Goda hena (lands above the tank or paddy field) Land Productivity Very fertile Moderately fertile Suitable Crops Mustard, black gram, mungbean and vegetables black gram, mungbean, vegetables and coarse grains Coarse grains and sesame Less fertile Sesame, meneri Imperfectly drained lowlands Paddy, vegetables Fertile When the chena land becomes unproductive, they move to another location and practice the same cultivation. Tank is the heart of village. If the tank does not function well, it affects their lives. Thus, tank is repaired continuously. They look after the surrounding vegetation, which has many uses. It makes the inflow clear, reduces the evaporation, minimizes seepage and creates favourable environment for the fish community. People not only harvest fish from the tank but also gather various food plants. Thus, the tank is a multi-purpose system. Ignorance of the tank increases the severity of the drought. Fig. 2 shows the eco-system of the tank-village. Its major components and their functions are described below Fig. 2. Tank-village Eco-system Gasgommana (Upstream tree belt) - It is the upstream land strip above the tank bed, accommodating water only when spilling. Large trees such as kumbuk, nabada, maila, damba etc. and climbers such as kaila, elipaththa, katukeliya, kalawel, bokalawel etc. are found in this area. This vegetation is natural and seeds are floating on water. The gasgommana acts as a wind barrier reducing evaporation from the tank and lowering water temperature. It gets closure 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 tree demarcates the territory between human and wild animals. Perahana (sediment filter) – It is the meadow developed under gasgommana and filters the sediment flow coming from upstream chena lands. Iswetiya or potawetiya (soil ridge) - An upstream soil ridge constructed at either side of the tank bund to prevent entering eroded soil from upper land slopes. Godawala (water hole) - A manmade water hole to trap sediment and it provides water to wild animals. This might had been a strategy to evade man-animal conflict. Kuluwewa (wild tank) - A small tank constructed above relatively large reservoirs only to trap sediment and not for irrigation purpose. It provides water for cattle and wild animals. Kattakaduwa (downstream reservation or the interceptor) – 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 the bund stability. It appears to be a 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. Specifically they harvest row materials from this vegetation for cottage industries. Some products derived from the vegetation of kattakaduwa are shown below. Plant species Indi Vetakeya Bambo Rattan Palmaira Mat grass Pata-beli Products Hats, bags, baskets Bags, baskets, mats. Wood carving, flower vase, building materials Baskets, furniture Mats, bags, baskets, sweets, toddy Mats, baskets etc. Ropes, strings etc. Tisbambe (hamlet buffer) – 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 sanitary purposes as the resting place of buffaloes. Buffaloes were used as a protection mechanism from wild animals and malaria. Kiul ela (drainage) – 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 polluted water and improves the drainage condition of the paddy tract. Sustainable traditional villages with the above environmental components had been in existence up to recent past, but it has been deteriorated and collapsed during last few decades. We talk about drought and its consequences, while sadly observing the disappearing sustainability of the traditional tank-villages. However, being proud of what we had in the past is not adequate leaving the real issue of the tank-village community faced at present. Although we can not achieve the prosperity we had in the past in the same manner, we might be able to understand many aspects of sustainability and the important lessons and best practices. Perhaps the traditional communities in the dry zone were compelled to conserve resources and achieve food security merely to struggle against the drought, which frequently harassed them. Aiming to achieve the sustainable living, they seem to adopt following measures in using resources for their needs.  Groundwater was preserved without using for cultivation to assure the water security  They were accustomed to a risk evading faming  They gathered many from the environment for their needs without destroying it.  They were adjusted to live with minimum needs and in simplest way.  They harvested rainwater and utilized in most efficient manner.  They acted as a group in order to protect from wild animals, epidemics and droughts.  They stored food for future use.  They took care of being independent from external interventions.  They protected the knowledge they gathered in attempting to find methods and strategies to solve problems as an asset.  They considered mental relief and healthy environment as fundamental needs of a community. Our civilization has evolved on the foundation built up to stand still in front of natural disasters such as drought, flood, cyclone, epidemic etc. We must learn it again.