An Economic Analysis of Salinity Problems in the Mahaweli River System H Irrigation Scheme in Sri Lanka

Salinity problems are primarily associated with coastal areas and irrigated lands in the dry zone of Sri Lanka, where the total irrigated area is about 0.5 million hectares. Since irrigation has been practiced in these areas from ancient times, salinity might have been a problem at least in patches of irrigated lands. With the development of modern irrigation networks, it is anticipated that salinity would become a problem over the years as in many other countries. Only a few systematic studies exist on the soil salinization problem in Sri Lanka, and there are no records of the actual extent of lands affected by salinity, or data that indicate its trend. Most of the available information comes from sporadic surveys. Recently, however, concerns were expressed that most of the large-scale projects would face salinity problems. Due to the inadequacy of related studies, the actual extent of the problem, both in economic and environmental terms, is unknown in Sri Lanka. This study focused primarily on the problem of soil salinity in the Mahaweli irrigation scheme. The Mahaweli project is one of the largest irrigation projects in South East Asia. This study attempted to measure the impact of soil salinization on rice production and on the environment. It also assessed the optimal control of salinity at the farm and project level for better water management and environmental protection.Salinity, Sri Lanka

Too Much Salt In The Rice Bowl: Irrigation In Sri Lanka

Salination is a major problem for agriculture in many parts of the world. However, this study from Sri Lanka has shown that the involving farmers in preventative measures can provide a cost-effective solution. The study looked at one of the largest irrigation schemes in Southeast Asia. The study concluded that salination represents a real threat to the scheme and that drainage improvement represents the best permanent solution to the issue.Salt, rice bowl, Sri Lanka

Drivers of the adoption of farmer-innovated sprinkler irrigation systems: evidence from Kalpitiya, Sri Lanka

Since the 1980s, along with many other countries, Sri Lanka rapidly embraced groundwater irrigation. At the same time, the government, externally funded projects and nongovernmental organizations (NGOs) made bold efforts to promote water-saving technologies, such as drip and sprinkler irrigation systems, among farmers, but achieved little or no success. Despite the continuous failure in the promotion of 'professionally designed', micro-irrigation systems across the country, grassroots innovations have emerged. These locally initiated endeavors, mainly in sprinkler irrigation, have been adopted comfortably and competently by the farmers themselves without any external assistance. Farmers in the Kalpitiya Peninsula have adopted this technology within a few years. This paper presents the 'drivers' behind this spontaneous 'irrigation revolution' that has occurred in the peninsula. The findings indicate that the adoption of sprinkler irrigation in this groundwater-based agricultural ecosystem has brought in tremendous changes to agricultural practices, and also to the lifestyles and livelihoods of the people living in the area. These positive and desirable results have been obtained with zero subsidy provision, and without any external inputs from the government or NGOs. Adoption of this sprinkler system for irrigation has increased the net sown area, net irrigated area and cropping intensity, resulting in significant economic returns and welfare gains. The low-cost sprinkler innovations are considered as an input cost that is recoverable within a year or two, rather than a long-term capital investment. The main drivers of this technological shift are (i) significant reduction in the cost of irrigation due to lower expenditure on labor and energy; (ii) user-friendly and affordable technology; (iii) easy to assemble, install and manage (operation and maintenance); (iv) easy access to components and spare parts (locally available); (v) potential to cultivate high-value cash crops; (vi) environmental context of the area (high number of rainless days, year-round availability of groundwater resources, low water-holding capacity of sandy soil); and (vii) immediate connection to markets through mobile phones and improved road networks. Promotion of micro-irrigation exclusively as a water-saving technology, as done in the past, is not a motive for farmers to adopt micro-irrigation systems. This is particularly the case where farmers do not recognize water scarcity as a 'real constraint'. Conserving water and sustainable management of the resource, at least for the time being, is not factored in farmers decision making

Impact of agricultural activities on groundwater quality and its suitability for drinking in Valikamam area, Jaffna Peninsula

In Sri Lanka Water Partnership (Lanka Jalani); International Water Management Institute (IWMI); Unilever-Pureit. Proceedings of the First Young Water Professionals Symposium, Colombo, Sri Lanka, 22-23 November 2012. Colombo, Sri Lanka: Sri Lanka Water Partnership (Lanka Jalani); Colombo, Sri Lanka: International Water Management Institute (IWMI); Colombo, Sri Lanka: Unilever-Purei

Managing shallow aquifers in the dry zone of Sri Lanka

This study looks at the groundwater issues in the dry zone of Sri Lanka and shows how the use of remote sensing with high-resolution images can help in groundwater management. A new approach is developed for automatic extraction of the location of agrowells using high-spatial-resolution satellite imageries. As an example, three pilot sites in three different aquifer systems in the country are considered, and their highresolution images are analyzed over two temporal time periods. The analysis suggests that the well density in all three regions has increased over the last few years, indicating higher levels of groundwater extraction. Using the well inventory developed by this new approach, the water budgeting was prepared for the mainland of Jaffna Peninsula. The analysis shows a wide variation in well density in the Jaffna Peninsula, ranging from (as little as) less than 15 wells per square kilometer to (as high as) more than 200 wells per square kilometer. Calculations made for the maximum allowable water extraction in each administrative division of Jaffna show that less than 3 h of daily extraction per well is possible in some districts. This points to an increasing pressure on groundwater resources in the region and thus highlights the importance of understanding groundwater budgets for sustainable development of the aquifers

Geo-statistical approach for prediction of groundwater quality in Chunnakam Aquifer, Jaffna Peninsula

Chunnakam aquifer is the main limestone aquifer of Jaffna Peninsula. The population of the Jaffna Peninsula depends entirely on groundwater resources to meet all of their water requirements. Thus for protecting groundwater quality in Chunnakam aquifer, data on spatial and temporal distribution are important. Geostatistics methods are one of the most advanced techniques for interpolation of groundwater quality. In this study, Ordinary Kriging and IDW methods were used for predicting spatial distribution of some groundwater characteristics such as: Electrical Conductivity (EC), pH, nitrate as nitrogen, chloride, calcium, carbonate, bicarbonate, sulfate and sodium concentration. Forty four wells were selected to represent the entire Chunnakam aquifer during January, March, April, July and October 2011 to represent wet and dry season within a year. After normalization of data, variogram was computed. Suitable model for fitness on experimental variogram was selected based on less Root Mean Square Error (RMSE) value. Then the best method for interpolation was selected, using cross validation and RMSE. Results showed that for all groundwater quality, Ordinary Kriging performed better than IDW method to simulate groundwater quality. Finally, using Ordinary Kriging method, maps of groundwater quality were prepared for studied groundwater quality in Chunnakam aquifer. The result of Ordinary Kriging interpolation showed that higher EC, chloride, sulphate and sodium concentrations are clearly shown to be more common closer to the coast, and decreasing inland due to intrusion of seawater into the Chunnakam aquifer. Also higher NO3 - - N are observed in intensified agricultural areas of Chunnakam aquifer in Jaffna Peninsula

Seasonal variation of Nitrate-N in groundwater: a case study from Chunnakam aquifer, Jaffna Peninsula [Abstract only]

In Ileperuma, O.; Priyantha, N.; Chandrajith, R.; Navaratne, A.; Perera, A.; Yatigammana, S.; Wijesundara, S.; Rathnayake, S. (Eds). 2013. Proceedings of the Second International Symposium on Water Quality and Human Health: Challenges Ahead, Peradeniya, Sri Lanka, 15-16 March 2013. Peradeniya, Sri Lanka: University of Peradeniya. Postgraduate Institute of ScienceThe Jaffna Peninsula has four main aquifer systems, of which the largest Chunnakam aquifer is in the Valikamam area. This is an intensively cultivated area in the Jaffna Peninsula, and consequently, excessive application of nitrogen fertilizer is found. Other sources of nitrate include organic manures, and urine and excreta of animals through human activities. The aim of this study was to assess the N-nitrate contamination in drinking water of the Chunnakam aquifer, which was a sub-objective of a research project carried out by the International Water Management Institute (IWMI). Forty four (44) groundwater samples were collected from wells representing different uses and land use patterns. The sampling covered the period from January to December, 2011, representing all seasons. Nitrate-N in sampled water was determined colorimetrically using a spectrophotometer. The spatial variations of the water quality were mapped using ArcGIS 10. Nitrate-N values from domestic, domestic with home garden and public wells ranged from below 0.1 to 12.1 mg L'I. During the rainy season, 38% of the agro-wells exceeded the limit of WHO drinking water guidelines (10 mg L? I) and these were not suitable for drinking purposes. However, this percentage was 15% at the end of the dry season. A decreasing trend in nitrate-N concentration was observed from January to March. During the rainy season, the soil was wet enough up to the water table facilitating nitrate leaching. Nitrate-N found in most of the wells surrounded by areas with highland crops (onions, chillies, tobacco and brinjals) also exceeded the acceptable level (10 rug L'l). Even though these wells are used for agricultural purposes, people who work in the field use agro-wel1s for drinking. This water pollution is very likely related to the heavy use of N-based fertilizers for cultivation in the region. This leads to groundwater unsafe for drinking. Therefore, effective management of groundwater quality in the region is vital and further, creating awareness among population would possibly reduce the excessive use of chemical fertilizers in agriculture

Groundwater development through sprinkler irrigation: consequences of a lack of a governance structure in Kalpitiya, Sri Lanka

Groundwater provides nearly 100 % of the water supplies in some districts of Sri Lanka and is a major source of domestic water in all other districts. However, the resource remains largely neglected and invisible to society and policymakers. Groundwater offers the advantage of being a more reliable and readily available resource for agriculture, and offers the basis for a ‘silent revolution’ in many areas. A groundwater-supported agricultural boom has, while imparting a large number of benefits, created its own set of obstinate problems, including over-exploitation and depletion of groundwater resources. In some districts, over-exploitation is putting the livelihoods of farmers that have come to depend on groundwater resources in jeopardy. Micro-irrigation technologies have been widely promoted as a means of reducing water demand by enhancing farm-level water-use efficiency. These technologies are proven to improve irrigation uniformity; increase irrigation application efficiency, by reducing soil evaporation and seepage losses; and increase crop productivity. It is assumed that using these technologies will enable water to be reallocated for other uses. The Government of Sri Lanka has made repeated attempts to promote micro-irrigation as a means of improving irrigation performance to minimize water scarcity in areas of the Dry Zone. These attempts have involved providing substantial heavy subsidies, but have met with little success in terms of adoption of ‘professionally designed’ installations. However, in Kalpitiya, farmers have adopted a locally designed sprinkler technology within a short period of time without subsidies and professional design inputs. This paper reviews the evolving agricultural boom as a result of groundwater and sprinkler irrigation that has occurred on the Kalpitiya peninsula. The development of a farmer-led sprinkler technology is assessed with reference to improving livelihoods of the people, and the potential consequences on sustainable management of groundwater resources. The experiences in Kalpitiya show that, in the absence of effective groundwater governance and policies, supported with appropriate institutions, micro-irrigation has enabled the expansion of the cultivated area and crop intensification. This has increased, rather than decreased, net water use on the peninsula. The estimated increase in water withdrawals is 14,490 m3/ha /y. This indicates that promoting efficient technologies alone is not sufficient to achieve water savings, which requires control of overall abstractions and recharge levels to stabilize aquifer storage. In the absence of an appropriate regulatory framework and lack of political will to manage groundwater, it is recommended that the social framework and community governance arrangements are developed and strengthened to enable sustainable use of groundwater resources