Your search found 12 records
(Location: IWMI-HQ Call no: PER Record No: H038495)
2 Galagedara, L. W. (Ed.) 2005. Water resources research in Sri Lanka: symposium proceedings of the Water Professional’s Day 2005. Peradeniya, Sri Lanka: University of Peradeniya, Post Graduate Institute of Agriculture. 215p.
(Location: IWMI HQ Call no: IWMI 631.7 G744 GAL Record No: H040700)
3 Mikunthan, T. 2005. Status of groundwater quality in Jaffna Peninsula: Special reference to nitrate and chloride. In Galagedara, L. W. (Ed.). Water resources research in Sri Lanka: Symposium Proceedings of the Water Professional’s Day 2005. Peradeniya, Sri Lanka: PGIA. pp.153-162.
(Location: IWMI HQ Call no: IWMI 631.7 G744 GAL Record No: H040713)
4 Prado, M. C. C. M.; Hiscock, K. M.; Rajasooriyar, L.; Boelee, Eline. 2010. Application of a combined hydrochemical and stable isotope approach to the study of the interaction between irrigation canal water and groundwater in southern Sri Lanka. [Abstract only]. In International Symposium, Sustainable Agriculture for Prosperity, Faculty of Agriculture, University of Ruhuna, Sri Lanka, 16 November 2010. Proceedings, Part 1 - Keynote speeches and abstracts. Kamburupitiya, Sri Lanka: University of Ruhuna. Faculty of Agriculture. pp.58.
(Location: IWMI HQ Call no: 630 G000 INT Record No: H043342)
(0.6MB)
5 Arasalingam, Sutharsiny; Pathmarajah, S.; Mikunthan, T.; Vithanage, M.; Manthrithilake, Herath. 2013. 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-Pureit. pp.74-81.
(Location: IWMI HQ Call no: 333.91 G744 SRI Record No: H046158)
(0.64 MB) (5.26 MB)
(Location: IWMI HQ Call no: 551.48011 G000 ELA Record No: H046634)
(0.52 MB)
7 Hasan, M. R.; Shamsuddin, M.; Masud, M. S.; Hossain, A. F. M. A. 2015. Groundwater salinity zoning for development plans: a case study of four sub-districts in the southwestern coastal region of Bangladesh. In Humphreys, E.; Tuong, T. P.; Buisson, Marie-Charlotte; Pukinskis, I.; Phillips, M. (Eds.). Proceedings of the CPWF, GBDC, WLE Conference on Revitalizing the Ganges Coastal Zone: Turning Science into Policy and Practices, Dhaka, Bangladesh, 21-23 October 2014. Colombo, Sri Lanka: CGIAR Challenge Program on Water and Food (CPWF). pp.53-60.
(Location: IWMI HQ Call no: IWMI Record No: H047193)
(0.51 MB) (11.9 MB)
(Location: IWMI HQ Call no: e-copy only Record No: H048190)
(4.76 MB)
Recharge assessment is a challenge in snow and glacier dominated Himalayan basins. Quantification of recharge to karst springs in these complex geological environments is important both for hydrologic understanding and for effective water resource management. We used spring hydrographs and environmental tracers (isotopes and solutes) to distinguish and estimate the sources of spring water and to identify the flow paths of the recharging waters in three mountainous basins of the western Himalaya. The karst springs are perennial with high discharge amplitudes. The results indicate that ambient temperature has a strong influence on the hydrological behavior of the springs. Although the spring flow is dominantly controlled by the melting of snow and/or glaciers, rain events produce sharp spikes in spring hydrographs. The facies patterns in springs within the Bringi basin (Ca-HCO3) and the Liddar basin (Ca-HCO3 and Ca-Mg-HCO3) suggest flow dominantly through limestone and dolomite. Higher concentrations of SO4 2 and Na+ in warm springs of the Kuthar basin indicate flow through carbonate, silicate and other rocks. The isotopic composition (d18O, d2 H) of precipitation, snowpacks, glacier melt and karst springs show wide variation both in space and time, and are strongly influenced by the basin relief and meteorology. The tracer-based two- and three-component mixing models suggest that the snowmelt dominantly contributes to the spring flow (55–96%), followed by glacier melt (5–36%) and rain (4–34%). Based on tracer tests with good recovery rates, springs are dominantly recharged through point sources rather than by diffuse infiltration. Changes in the timing, form, and amount of winter precipitation substantially affect the timing and magnitude of spring discharge during the rest of the year.
(Location: IWMI HQ Call no: e-copy only Record No: H048891)
A water and soil quality baseline study was carried out across the ~ 4500 km2 Vientiane Plain in Lao PDR. Eight water quality and nine soil parameters were analysed using field kits at 95 sites in March 2015. Elevated electrical conductivity and chloride were apparent at two sites due to geogenic leaching from the marine rock-salt present in some areas. Groundwater was acidic in most locations. Nitrate and faecal contamination were also observed from nitrogenous fertilizers (diffuse) and from leaky sewage pits (localised) respectively. Soil quality is neither nutrient deficient nor does it pose a threat to plant growth. Where groundwater is used for drinking, removal of bacterial contamination by simple filtration or boiling is sufficient. In the absence of a functional monitoring network in the Vientiane Plain, periodic surveys of this kind should be performed. The results should be made widely available to the relevant government departments and other stakeholders for better management of the land and water resources.
(Location: IWMI HQ Call no: e-copy only Record No: H049793)
(1.49 MB)
Understanding recharge processes is fundamental to improve sustainable groundwater resource management. Shallow groundwater (SGW) is being developed for multiple purposes in Ethiopia without consideration of monitoring. We established a citizen science-based hydro-meteorological monitoring network, with a focus on SGW recharge estimation, in Eshito micro-watershed, Ethiopia. Citizen scientists collected rainfall, groundwater-level and stream water-level data. We characterized the shallow aquifer using pumping tests. The data were used to estimate SGW recharge using three methods: chloride mass balance, water-level fluctuation (WLF) and baseflow separation. Approximately 20% and 35% of annual rainfall amount contributes to recharge based on the chloride mass balance and WLF results, respectively. Baseflow separation showed recharge values for the watershed vary from 38% to 28% of annual rainfall at the upstream and downstream gauging stations, respectively. This study shows that the recharge in previously unmonitored micro-watersheds can be studied if citizens are involved in data generation.
(Location: IWMI HQ Call no: e-copy only Record No: H050842)
(4.32 MB) (4.32 MB)
Study region: Awash River Basin, Ethiopia
Study focus: Many river basins in sub-Saharan Africa have become vulnerable due to the impact from climate change, weak governance and high levels of poverty. One of the primary concerns is the elevated salinity and the degradation of water quality in the Awash River. Located in the Great Rift Valley in Ethiopia, the Awash River has unique hydrochemistry due to water-rock interactions. However, in recent years, increasing anthropogenic activities including the discharge from saline Lake Beseka into the Awash River has caused some concern. This study used an Integrated Catchment Model to simulate chloride concentration in the Awash River Basin by taking both natural and anthropogenic sources of salinity into consideration. Future scenarios of climate change and Lake Beseka discharge were examined to assess the impact to the river water quality.
New hydrologic insights: Results show that Lake Beseka has made significant contribution to the rise of the salinity in the Awash River. If the trend of human interference (e.g. increased irrigation and unregulated water transfer) continues, the river downstream of Lake Beseka could see Cl increases up to 200 % in the near future (2006–2030). The modeling results are essential for generating long term plans for proper utilization of water resources especially in the region where the resources and the economic capacity to meet the water demand is lacking.
(Location: IWMI HQ Call no: e-copy only Record No: H051839)
(8.28 MB) (8.28 MB)
Nitrate is globally the most widespread and widely studied groundwater contaminant. However, few studies have been conducted in sub-Saharan Africa, where the leaching potential is enhanced during the rainy monsoon phase. The few monitoring studies found concentrations over drinking water standards of 10 mg N-NO3 - L -1 in the groundwater, the primary water supply in rural communities. Studies on nitrate movement are limited to the volcanic Ethiopian highlands. Therefore, this study aimed to evaluate the transport and fate of nitrate in groundwater and identify processes that control the concentrations. Water table height, nitrate, chloride, ammonium, reduced iron, and three other groundwater constituents were determined monthly in the groundwater in over 30 wells in two contrasting volcanic watersheds over two years in the Ethiopian highlands. The first watershed was Dangishta, with lava intrusion dikes that blocked the subsurface flow in the valley bottom. The water table remained within 3 m of the surface. The second watershed without volcanic barriers was Robit Bata. The water table dropped rapidly within three months of the end of the rain phase and disappeared except near faults. The average nitrate concentration in both watersheds was between 4 and 5 mg N-NO3 - L -1 . Hydrogeology influenced the transport and fate of nitrogen. In Dangishta, water was blocked by volcanic lava intrusion dikes, and residence time in the aquifer was larger than in Robit Bata. Consequently, nitrate remained high (in several wells, 10 mg N-NO3 - L -1 ) and decreased slowly due to denitrification. In Robit Bata, the water residence time was lower, and peak concentrations were only observed in the month after fertilizer application; otherwise, it was near an average of 4 mg N-NO3 - L -1 . Nitrate concentrations were predicted using a multiple linear regression model. Hydrology explained the nitrate concentrations in Robit Bata. In Dangishta, biogeochemistry was also significant.
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