Your search found 15 records
1 Hoanh, Chu Thai; Senaratna Sellamuttu, Sonali; Joffre, O.; McCartney, Matthew; Lacombe, Guillaume; Kam, S. P.; Baran, E.; Reis, J.; Metzger, L.; Teoh, Shwu; Yen, B. T.; Douangsavanh, Somphasith; Keophoxay, Anousith; Douangsavanh, L.; Xayachack, S.; Toan, T. D.; Phuong, N. D. 2011. A decision-support-system (DSS) framework for linking livelihoods with reservoir operation: experiences from MK1 case studies in the Mekong Basin. [Abstract only]. Paper presented at the 3rd International Forum on Water and Food, Tshwane, South Africa, 14-17 November 2011. 2p.
Decision support systems ; Water power ; Reservoirs ; Case studies ; River basins ; Impact assessment ; Aquaculture ; Agriculture ; Development projects / South East Asia / Latin America / Asia / Africa / Laos / Cambodia / Mekong River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H044565)
http://mahider.ilri.org/bitstream/handle/10568/10453/MLiSe004_Final_RD_1710.pdf?sequence=1
https://vlibrary.iwmi.org/pdf/H044565.pdf
https://vlibrary.iwmi.org/pdf/H044565.pdf
(0.65 MB) (668.76KB)
2 McCartney, Matthew; Lacombe, Guillaume; Reis, J.; Hoanh, Chu Thai; Douangsavanh, Somphasith. 2011. Review of water resource and reservoir planning models for use in the Mekong Basin to improve livelihoods of local people impacted by reservoir development. [Abstract only]. Paper presented at the 3rd International Forum on Water and Food, Tshwane, South Africa, 14-17 November 2011. 2p.
Water resources ; Water management ; Reservoirs ; Simulation models ; River basins ; Environmental effects ; Social aspects / South East Asia / Mekong River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H044566)
http://mahider.ilri.org/bitstream/handle/10568/10547/MSSe002_Final_RD_1810.pdf?sequence=1
https://vlibrary.iwmi.org/pdf/H044566.pdf
https://vlibrary.iwmi.org/pdf/H044566.pdf
(0.42 MB) (241.40KB)
3 Lacombe, Guillaume; Douangsavanh, Somphasith; Thepphavong, B.; Hoanh, Chu Thai; Bounvilay, B.; Noble, Andrew; Ongkeo, O.; Johnston, Robyn; Phongpachith, C. 2011. Is there enough water in the Vientiane Plain? a water balance assessment of the Lower Nam Ngum Basin. Project report prepared by IWMI for CSIRO - AusAID Research for Development Alliance under the project "Exploring Mekong Region Futures". Vientiane, Laos: International Water Management Institute (IWMI). 25p.
Water balance ; Assessment ; Water demand ; Water supply ; River basins ; Water power ; Dams ; Irrigated land ; Pumping ; Time series analysis / Laos / Vientiane Plain / Nam Ngum River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H044647)
(1.14 MB)
In Lao PDR, one of the less developed countries, water represents a valuable natural resource via the development of hydropower dams and irrigation schemes. In the lower part of the Nam Ngum River Basin, the Vientiane plain is one of the largest food production areas of the country and the largest irrigated area in Lao PDR. While food demand is expected to continue to increase in the future, hydropower dams are under rapid development in the upper part of the basin, modifying the seasonal distribution of the river flow regimes. This study aims at assessing the current water supply and agricultural water demand in the Vientiane Plain and concluding whether the water resource is or may become a limiting factor for food production. The agricultural water demand is assessed from two types of data (characteristics of large-scale pumping stations and official statistics on irrigated areas) and using remote sensing analyses. Flow measurements of the Nam Ngum River were used to quantify the water supply. A 43-year time series (1962-2004) of daily river discharge was reconstructed from actual discontinuous data recorded in the river reach where most of the pumping stations are found. Distinctions in the water resource assessment were made between pristine conditions (before the construction of the hydropower dams) and current conditions of water infrastructure development. A comparison of the water supply and demand indicates that during the 4 driest months of the year (January to April) when the river reaches its minimum level and the irrigation water demand is the highest, pumped volumes represent less than 30% of the river discharge. This ratio should decrease as new hydropower dams are built, storing and releasing more water during the wet and the dry season, respectively. These figures indicate that the availability of water in the Nam Ngum River is not a limiting factor for irrigation, even during the dry seasons of exceptionally dry years. The water demand could exceptionally exceed the water supply in the case of an extreme scenario of irrigation development with irrigated areas 3-fold larger than the current ones. Next analyses will consist in assessing how this water balance will be altered by the development of new hydropower dams and irrigation projects. Possible uses of water surplus will be prioritized, depending on their economic viability and benefits.
4 Lacombe, Guillaume; Douangsavanh, Somphasith; Baker, J.; Hoanh, Chu Thai; Bartlett, R.; Phongpachith, C.; Jeuland, M. 2013. Hydropower and irrigation development: implications for water resources in the Nam Ngum River of the Mekong Basin. [Abstract only]. In German Aerospace Center (DLR); Germany. Federal Ministry of Education and Research (BMBF). Mekong Environmental Symposium, Ho Chi Minh City, Vietnam, 5-7 March 2013. Abstract volume, Topic, 10 - Impacts of urbanization and industrialisation on agriculture and water resources. Wessling, Germany: German Aerospace Center (DLR); Bonn, Germany: Federal Ministry of Education and Research (BMBF). pp.176.
Water power ; Dams ; Irrigation development ; Water resources development ; River basins ; Irrigation water ; Water demand / South East Asia / Laos / Mekong River Basin / Nam Ngum River
(Location: IWMI HQ Call no: e-copy only Record No: H045754)
(2.09MB)
To meet rising demands for food and energy, the number of hydropower dams is growing rapidly and irrigation schemes will likely expand, in the Mekong Basin. The cumulative hydrological effect of planned water resources development has previously been assessed at the Mekong Basin scale. This paper analyzes how water control structures modify the balance between water demand and water supply along the Nam Ngum River, a Mekong tributary in Lao PDR. The Nam Ngum Basin, already containing both irrigation schemes and hydropower dams, has the potential for significantly enlarged river-fed irrigation, as well as additional upstream hydropower dams. We analyzed flow data recorded since 1962, in combination with a reservoir system optimization model, to assess changes in monthly river flows induced by existing and planned hydropower dams. Current and potential irrigation water demands were assessed from satellite images, cropping calendars and simple crop water balance. Our results indicate that, by the 2030s, if eight hydropower dams are completed in the Nam Ngum Basin, dry season river flow could increase by more than 200% and wet season flows could decrease by 20%. In the absence of dam storage, current irrigation water demand would compete with minimum environmental flow requirements during dry years. In contrast, full hydropower development allows current irrigation water demand to triple, to reach the potential levels of development, whilst maintaining environmental flows. The contribution of the Nam Ngum Basin to the Mekong River flow at Kratie, a few hundreds kilometers upstream of the Tonle Sap Lake, has changed from 5 to 15% in April, since hydropower dams started developing in the Mekong Basin, suggesting that the effect of water control development in the Nam Ngum Basin impacts water resources further downstream. Beyond the effects on water resources, there are a number of other impacts on fisheries, sediment, biodiversity, ecosystems, and population resettlement that should be considered in order to better understand the environmental and socioeconomic costs and benefits of these hydropower dams.
5 Baker, J.; Bartlett, R.; Jeuland, M.; Lacombe, Guillaume; Douangsavanh, Somphasith. 2013. Analyzing economic tradeoffs of water use in the Nam Ngum River Basin, Lao PDR. [Abstract only]. In German Aerospace Center (DLR); Germany. Federal Ministry of Education and Research (BMBF). Mekong Environmental Symposium, Ho Chi Minh City, Vietnam, 5-7 March 2013. Abstract volume, Topic 02 - Hydropower development and impacts on economy. Wessling, Germany: German Aerospace Center (DLR); Bonn, Germany: Federal Ministry of Education and Research (BMBF). pp.39.
Water resources ; River basins ; Water demand ; Water use ; Water power ; Irrigated farming ; Economic aspects / Laos / Nam Ngum River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H045822)
http://www.mekong-environmental-symposium-2013.org/frontend/file.php?id=3020&dl=1
https://vlibrary.iwmi.org/pdf/H045822.pdf
https://vlibrary.iwmi.org/pdf/H045822.pdf
(0.08 MB) (2.09MB)
6 Bartlett, R.; Baker, J.; Lacombe, Guillaume; Douangsavanh, Somphasith; Jeuland, M. 2012. Analyzing economic tradeoffs of water use in the Nam Ngum River Basin, Lao PDR. Durham, NC, USA: Duke University. Nicholas Institute for Environmental Policy Solutions. 37p. (Duke Environmental Economics Working Paper Series)
Water management ; Water use ; River basins ; Economic development ; Energy generation ; Water power ; Dams ; Irrigated sites ; Irrigated farming ; Flood control ; Models ; Data / Laos
(Location: IWMI HQ Call no: e-copy only Record No: H045852)
http://sites.nicholasinstitute.duke.edu/environmentaleconomics/files/2013/01/WP-EE-12-10.pdf
https://vlibrary.iwmi.org/pdf/H045852.pdf
https://vlibrary.iwmi.org/pdf/H045852.pdf
(0.68 MB) (703.52KB)
This paper develops a hydro-economic optimization modeling framework to assess the economic consequences and potential trade-offs of various infrastructure development and policy pathways in the Nam Ngum Basin (Lao PDR). We considered whether large shifts in water resource demands in a relatively water abundant basin could induce meaningful economic trade-offs among water uses, including hydropower generation, irrigation expansion, flood control, and transboundary water transfer objectives. We constructed a series of sensitivity scenarios under dry, average, and wet hydrologic conditions with varying levels dam development, irrigated agricultural expansion, agricultural returns, flood control storage restrictions, and water diversions to Northeast Thailand. We also considered how flows into the Mekong would be affected by these collective developments. In general, results indicate that tradeoffs between hydropower production, irrigation, and flood control are modest. Hydropower and agricultural expansion are found to be complimentary under high levels of water availability, even with the most ambitious level of irrigation expansion. Allowing for flood control by maintaining reduced storage levels in the reservoir that is largest and furthest downstream on the Nam Ngum (NN1) has a minimal effect on economic output and decreases total system hydropower by less than 1%. However, economic outcomes are highly dependent on water availability and economic returns to irrigated agriculture. System hydropower was greatly reduced, and inter-basin transfer projects induced large economic costs under dry conditions. These results on seasonal impacts illustrate the importance of accounting for climate variability and potential hydrologic change in cost-benefit analysis of infrastructure projects, even in watersheds that are relatively water abundant.
7 McCartney, Matthew; Pavelic, Paul; Lacombe, Guillaume; Latt, K.; Zan, A. K.; Thein, K.; Douangsavanh, Somphasith; Balasubramanya, Soumya; Rajah, Ameer; Myint, A.; Cho, C.; Johnston, Robyn; Sotoukee, Touleelor. 2013. Water resources assessment of the dry zone of Myanmar: final report for component 1. [Project report of the Livelihoods and Food Security Trust Fund (LIFT) Dry Zone Program] Vientiane, Laos: International Water Management Institute (IWMI); Yangon, Myanmar: National Engineering and Planning Services (EPS). 52p.
Water resources ; Surface water ; Water use ; Flow discharge ; Runoff ; Groundwater resources ; Groundwater recharge ; Water quality ; Water storage ; Reservoirs ; Aquifers ; Evapotranspiration ; Water supply ; Irrigation schemes ; Assessment ; Arid zones ; Food security ; Living standards ; Rain ; Data ; Geology ; Research projects / Myanmar / Dry Zone
(Location: IWMI HQ Call no: e-copy only Record No: H046133)
(3.66 MB)
8 Johnston, Robyn; Rajah, Ameer; Balasubramanya, Soumya; Douangsavanh, Somphasith; Lacombe, Guillaume; McCartney, Matthew; Pavelic, Paul; Senaratna Sellamuttu, Sonali; Sotoukee, Touleelor; Suhardiman, Diana; Joffre, O. 2013. Identifying priority investments in water in Myanmar’s dry zone: final report for component 3. [Project report of the Livelihoods and Food Security Trust Fund (LIFT) Dry Zone Program] Vientiane, Laos: International Water Management Institute (IWMI). 53p.
Water resources development ; Water management ; Water supply ; Research projects ; Investment ; Living standards ; Arid zones ; Agroecosystems ; Irrigation systems ; Irrigation schemes ; Groundwater irrigation ; Supplemental irrigation ; Rainwater ; Water harvesting ; Water storage ; Reservoirs ; Dams ; Wells ; Watershed management ; Food security ; Farmland ; Rainfed farming ; Irrigated farming ; Social aspects / Myanmar / Dry Zone
(Location: IWMI HQ Call no: e-copy only Record No: H046135)
9 Mekuria, Wolde; Noble, Andrew; Hoanh, Chu Thai; McCartney, Matthew; Sengtaheuanghoung, O.; Sipaseuth, N.; Douangsavanh, Somphasith; Langan, Simon; Getnet, Kindie. 2014. The potential role of soil amendments in increasing agricultural productivity and improving the livelihood of smallholders in Lao PDR. Paper presented at the 15th National Agriculture and Forestry Research Institute Anniversary Symposium on Agriculture and Forestry Research for Development, Vientiane, Lao PDR, 8-10 April 2014. 15p.
Agricultural production ; Water productivity ; Soil amendments ; Smallholders ; Living standards ; Maize ; Nutrient uptake ; Biomass ; Economic aspects ; Case studies / Lao People's Democratic Republic
(Location: IWMI HQ Call no: e-copy only Record No: H046433)
The present study was undertaken in Lao PDR to investigate the impacts of organic and clay-based soil amendments on maize yield, total nutrient uptake and crop water productivity (CWP), and analyze the economic return of such interventions. Structured field experiments were established over two consecutive years (2011 and 2012) with maize as the test crop at the Veunkham and Naphok sites. Ten treatments were applied in a Randomized Complete Block Design with three replications. The treatments were control, rice husk biochar (applied at a rate of 10 t ha-1), bentonite clay (10 t ha-1), compost (4 t ha-1), clay-manure compost (10 t ha-1), rice husk biochar compost (10 t ha-1), and their combinations. All treatments were applied in 2011. CWP and the soil water balance of the various treatments were determined using the AquaCrop model. To determine the costs and benefits of soil amendments over the two cropping seasons a cost-based valuation method was applied. Significant (p < 0.05) treatment effects in maize grain yields, total nutrient uptake and CWP were observed. At Veunkham, differences in yield between the control and amended soils ranged from 0.9 to 3.3 t ha-1 in 2011 and from 0.2 to 1.3 t ha-1 in 2012, whereas differences at Naphok varied between 0.2 and 2.2 t ha-1 in 2011 and from 0.2 to 1.7 t ha-1 in 2012. Differences in CWP between the amended and control plots at Veunkham varied between 0.3 and 1.0 kg m-3 in 2011 and from 0.05 to 0.29 kg m-3 in 2012, whereas differences at Naphok varied between 0.1 and 0.6 kg m-3 in 2011 and from 0.1 to 0.4 kg m-3 in 2012. Differences between the control and amended soils in yield and the associated CWP can be attributed to the improvements in total N and P uptake, soil pH, exchangeable Ca++ and Mg++, and CEC following the application of soil amendments. At both sites, in most of the treatments, yields and CWP in 2012 were significantly (p < 0.05) lower than 2011. This difference can be attributed to late season drought. Over the two cropping seasons , the enhancement of maize yield due to soil amendments resulted in net revenues ranging from -794 to 841 and -331 to 1391 US$ ha-1 at Naphok and Veunkham, respectively. The study found that soils amended with low-cost amendments such as compost, rice husk biochar, rice husk biochar compost, and clay-manure compost were economically viable within the first cropping season. In contrast, soils amended with higher-cost amendments such as bentonite clay required up to 5 years to be economically viable. Such variations indicate that maize yield revenues alone are an insufficient incentive for farmers to adopt higher-cost soil amendments. The results of this study confirm that soil amendments can be effective in improving crop yield and the associated CWP. In addition, the income of smallholders can be improved using locally available low-cost soil amendments. These findings provide important information for decision makers wishing to improve agricultural productivity and food security through sustainable intensification.
10 Lacombe, Guillaume; Douangsavanh, Somphasith; Vogel, R.; McCartney, Matthew; Chemin, Yann; Rebelo, Lisa-Maria; Sotoukee, Touleelor. 2014. Simple power-law models to predict flow metrics for water resource and risk management along the Mekong tributaries. [Abstract only] Paper presented at the International Conference on Sustainability in the Water-Energy-Food Nexus, Bonn, Germany, 19-20 May 2014. pp.59.
Water resources ; Risk management ; Statistical methods ; Models ; River basins ; Catchment areas / South East Asia / Mekong Basin
(Location: IWMI HQ Call no: e-copy only Record No: H046736)
https://publications.iwmi.org/pdf/H046736.pdf
http://wef-conference.gwsp.org/fileadmin/WEF_Conference/Conference_Programme_Sustainability_in_the_W-E-F_Nexus_web_version.pdf
http://wef-conference.gwsp.org/fileadmin/WEF_Conference/Conference_Programme_Sustainability_in_the_W-E-F_Nexus_web_version.pdf
(0.18 MB)
Increasing demographic pressure, economic development and resettlement policies in the Lower Mekong Basin induce greater population dependency on river flow to satisfy growing domestic and agricultural water demands. This dependency is particularly tight in upland areas where alternative water resources (groundwater) are scarce. As a result, communities tend to live closer to rivers, and so are more vulnerable to floods. This situation requires improved knowledge of flow variability for better management of water resources and risks. Unfortunately, stream flow measurements are scarce, especially in remote areas inhabited by the poorest and most vulnerable populations. Several water resource models have been developed to simulate and predict flows in the Lower Mekong Basin. However, most of these models have been designed to predict flow along the Mekong mainstream, precluding accurate assessments in headwater catchments. In most cases, their complexity and lack of transparency restricts potential users to modelling experts, and largely excludes those practitioners working closely with affected populations. The most integrated and informative way to characterize flow, at a specific location on a river, is to compute a flow duration curve which provides the percentage of time (duration) any particular flow is exceeded over a historical period. Using hydro-meteorological records from more than 60 gauged catchments in the Lower Mekong Basin, and a 90-meter digital elevation model, we used multiple linear regressions to develop power-law models predicting flow duration curves. These simple equations allow assessment of low, medium and high flow metrics, at any point on rivers in the Lower Mekong Basin, using easily determined geomorphological and climate characteristics. We believe that this parsimonious, transparent and highly predictive tool (89% <R2< 95%) can be used by a wide range of practitioners working in the fields of livelihood, water infrastructure engineering and agriculture.
11 Douangsavanh, Somphasith; McCartney, Matthew; Lacombe, Guillaume. 2014. Mapping irrigated areas in the dry zone of Myanmar by differentiating evapotranspiration from irrigated and rain-fed areas [Abstract only] In NARO/Hokkaido Agricultural Research Center. Agro-environmental Research Division. Proceedings of International Symposium on Agricultural Meteorology [ISAM], Hokkaido, Japan, 17-21 March 2014. Hokkaido, Japan: NARO/Hokkaido Agricultural Research Center. Agro-environmental Research Division. pp.179.
Irrigated sites ; Irrigation efficiency ; Arid zones ; Evapotranspiration ; Rainfed farming ; Water resources ; Water availability / Myanmar
(Location: IWMI HQ Call no: e-copy only Record No: H046760)
(0.34 MB)
In the Dry Zone of Myanmar, variability in water resources and insufficient capacity to manage that variability is one of the main causes of food insecurity. Seasonal water scarcity is widely acknowledged to be a key constraint to livelihoods and peoples’ wellbeing. This paper describes analyses conducted as a contribution to a detailed water resource assessment of the Dry Zone of Myanmar, which sought to provide information on current water availability and its use in agriculture. A key unknown is the area of dry season irrigation. The paper describes an attempt to estimate the actual area irrigated during the dry seasons (2011-2012) and to determine effective irrigation volumes by differentiating actual evapotranspiration (ET) in irrigated and rain-fed areas. The results indicate that 256,578 ha were irrigated. This contrasts with the total irrigable area of 344,257 ha as stated by the Irrigation Department (ID), the JICA estimate of 382,110 ha, and the FAO estimate of total irrigated area of 685,246 ha. ET in rain-fed and irrigated areas in conjunction with potential evapotranspiration (PET) were compared between three different areas located in the north, the center and the south of the Dry Zone. Actual water volume utilized by crops is much smaller than the volume of water diverted for irrigation, suggesting significant scope for improving irrigation efficiency.
12 Mekuria, Wolde; Noble, Andrew; McCartney, Matthew; Hoanh, Chu Thai; Douangsavanh, Somphasith; Langan, Simon. 2015. Soil management for raising crop water productivity in rainfed production systems in Lao PDR. Archives of Agronomy and Soil Science, 62(1):53-68. [doi: https://doi.org/10.1080/03650340.2015.1037297]
Soil management ; Soil amendments ; Soil organic matter ; Clay soils ; Crop production ; Water productivity ; Rainfed farming ; Climate change ; Evapotranspiration ; Land degradation ; Maize ; Biofuels ; Acidity / Lao People's Democratic Republic
(Location: IWMI HQ Call no: e-copy only Record No: H046994)
(0.26 MB)
This study investigated the impacts of organic- and clay-based soil amendments, and their combinations on crop water productivity (CWP) using maize as a test crop. On-station field trials were established over two consecutive years at the Naphok and Veunkham sites in Laos. At each site, 10 treatments were applied in a randomized complete block design with three replications. The treatments were control, rice husk biochar (10 t ha-1), bentonite clay (10 t ha-1), compost (4 t ha-1), clay-manure compost (10 t ha-1), rice husk biochar compost (10 t ha-1), bentonite clay + biochar, bentoniteclay + compost, biochar + compost, and bentonite clay + biochar + compost. All treatments were applied in 2011. Significant (p < 0.05) treatment effects in CWP and growing period evapotranspiration were determined. At Naphok, differences between the amended and control plots in CWP varied between 0.1 and 0.6 kg m-3 in 2011 and from 0.1 to 0.4 kg m-3 in 2012, whereas differences at Veunkham varied between 0.3 and 1.0 kg m-3 in 2011 and from 0.05 to 0.29 kg m-3 in 2012. At both sites, CWP in 2012 was significantly lower than 2011. Our results illustrate that organic- and claybased soil amendments improve CWP, indicating that soil-based interventions could be suitable options for improving agricultural productivity.
13 Pavelic, Paul; Senaratna Sellamuttu, Sonali; Johnston, Robyn; McCartney, Matthew; Sotoukee, Touleelor; Balasubramanya, Soumya; Suhardiman, Diana; Lacombe, Guillaume; Douangsavanh, Somphasith; Joffre, O.; Latt, K.; Zan, A. K.; Thein, K.; Myint, A.; Cho, C.; Htut, Y. T. 2015. Integrated assessment of groundwater use for improving livelihoods in the dry zone of Myanmar. Colombo, Sri Lanka: International Water Management Institute (IWMI) 47p. (IWMI Research Report 164) [doi: https://doi.org/10.5337/2015.216]
Irrigation systems ; Groundwater irrigation ; Aquifers ; Groundwater recharge ; Groundwater assessment ; Groundwater management ; Water use ; Water resources ; Water availability ; Water quality ; Water market ; Domestic water ; Living standards ; Arid zones ; Tube wells ; Pumping ; Social aspects ; Economic aspects ; Cost benefit analysis ; Investment ; Geology ; Hydrology ; Arsenic compounds ; Agriculture ; Sustainability ; Smallholders ; Farmers ; Case studies / Myanmar
(Location: IWMI HQ Call no: IWMI Record No: H047229)
(3 MB)
In the Dry Zone of Myanmar, improved access to water is widely acknowledged as being vital for livelihood enhancement and the general well-being of around 10 million people, most of whom depend on agriculture. Thus, expanding the sustainable use of groundwater is of great importance for socioeconomic development. According to this study, opportunities for accessing groundwater are generally good, and development of the resource has steadily increased over the years. However, there still appears to be good prospects for expanding groundwater use for irrigation, with a view to increasing agricultural production. Provision of affordable mechanical technologies for drilling wells and support with credit facilities to purchase small-capacity motorized pumps for irrigation could improve food security and livelihoods, where there is potential to expand groundwater use. Replenishable groundwater resources of the Dry Zone are likely to be less than previously thought. Thus, it is important to find the right balance between increasing development of the resource for enhanced irrigation, while also protecting its existing beneficial use for communities and the environment.
14 Brindha, Karthikeyan; Pavelic, Paul; Sotoukee, Touleelor; Douangsavanh, Somphasith; Elango, L. 2017. Geochemical characteristics and groundwater quality in the Vientiane Plain, Laos. Exposure and Health, 9(2):89-104. [doi: https://doi.org/10.1007/s12403-016-0224-8]
Geology ; Chemical composition ; Toxicity ; Groundwater ; Water quality ; Water level ; Drinking water ; Domestic water ; Irrigation water ; Aquifers ; Plains ; Heavy metals ; Pollutants ; Iron ; Arsenic ; Copper ; Zinc ; Mercury ; Health hazards / Lao People's Democratic Republic / Vientiane Plain
(Location: IWMI HQ Call no: e-copy only Record No: H047651)
Groundwater from the shallow aquifers of the Vientiane Plain, Laos is used for domestic needs including to some extent for drinking and for household gardening. The objective of this study is to assess the groundwater quality for drinking and irrigation activities and to determine the processes that lead to the presence of major ions in groundwater. Twenty groundwater samples were collected from a village on the Plain in December 2014, January 2015, and May 2015, and analysed for major ions and selected suite of minor ions and heavy metals. Groundwater is largely acidic, fresh and soft in nature. Geochemistry showed dominant Ca–Mg–HCO3 and mixed Ca–Na–HCO3 groundwater. Sodium impacts the suitability of water for irrigation to some extent. Hydrogeochemical processes identified and verified through factor analysis indicate weathering, carbonate dissolution, ion exchange, and anthropogenic sources including salinisation, due to irrigation and use of fertilizers as sources for the occurrence of major ions at such concentrations in this area. Only concentrations of lead and iron were above the permissible limits with arsenic, copper, zinc, mercury, and uranium found to be within safe limits. Background sample (groundwater) collected 5 km from the study area and the bottled water sample were all within suitable limits for drinking. This study is the first to provide a local-level assessment of geochemical processes in groundwater of this area indicating that the groundwater does not pose any threat to human health if used for drinking based on major ions, minor ions and a suite heavy metals except for iron and lead.
15 Pavelic, Paul; Suhardiman, Diana; Keovilignavong, Oulavanh; Clement, Corentin; Vinckevleugel, Jordan; Bohsung, Seinab M.; Xiong, Kong; Valee, Lengya; Viossanges, Mathieu; Douangsavanh, Somphasith; Sotoukee, Touleelor; Villholth, Karen G.; Shivakoti, B. R.; Vongsathiane, K. 2022. Assessment of options for small-scale groundwater irrigation in Lao PDR. In Re, V.; Manzione, R. L.; Abiye, T. A.; Mukherji, Aditi; MacDonald, A. (Eds.). Groundwater for sustainable livelihoods and equitable growth. Leiden, Netherlands: CRC Press - Balkema. pp.347-363. (IAH - International Contributions to Hydrogeology 30) [doi: https://doi.org/10.1201/9781003024101-19]
Groundwater irrigation ; Small scale systems ; Assessment ; Wells ; Boreholes ; Water use ; Crop production ; Cash crops ; Farmers ; Livelihoods ; Households ; Investment / Lao People's Democratic Republic / Vientiane Plain / Ekxang
(Location: IWMI HQ Call no: IWMI Record No: H051160)
(2.09 MB)
Groundwater offers smallholder farmers in the lowlands of Lao PDR opportunities to diversify cropping beyond wet season paddy and thus enhance their livelihoods while reducing climate risks. This chapter focuses on evaluating existing and specifically developed groundwater irrigation options on the Vientiane Plain, and framing the findings around the livelihood priorities of different farming groups against a backdrop of agrarian change. Results show that cultivating a range of cash crops using shallow dugwells managed by individual farmers and deeper boreholes managed by the community can be profitable for farmers, while helping to increase the resilience of farming households’ livelihoods. Both options may also represent a viable investment option for farming households lacking access to surface water irrigation, and thus contribute to more equitable growth. The results identify drivers and conditions that incentivize and enable groundwater irrigation to generate positive development outcomes. It also highlights that farmers will not intrinsically engage in groundwater irrigation simply because a good resource is available, but instead, weighs up the pros and cons of a mix of biophysical, socioeconomic, technical, and institutional factors. Agricultural policies aiming to intensify small-scale groundwater irrigation should be cognizant of these nuances as they are critical to successful implementation and management.
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