Can groundwater secure drinking-water supply and supplementary irrigation in new settlements of North-West Cambodia?

• Published in: Hydrogeology journal 2016-02, Vol.24 (1), p.195-209
• Main Authors: Vouillamoz, Jean Michel, Valois, Rémi, Lun, Sambo, Caron, Delphine, Arnout, Ludovic
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Aquifers; Boreholes; Cambodia; Civil war; Crop production; drilling; Drinking water; Dry season; Earth and Environmental Science; Earth Sciences; Environmental Sciences; Geology; Geophysical methods; Geophysics; Geophysics/Geodesy; Groundwater; Groundwater irrigation; Groundwater recharge; Groundwater storage; Hydrogeology; Hydrology/Water Resources; infrastructure; Irrigation; Irrigation water; monsoon season; paddies; Rainy season; Recharging; Sandstone; Specific yield; Transmissivity; Waste Water Technology; Water Management; Water Pollution Control; Water Quality/Water Pollution; Water resources; Water supply; wet season
• ISSN: 1431-2174; 1435-0157
• DOI: 10.1007/s10040-015-1322-6

Since the end of the Cambodian Civil War in 1998, the population of the Oddar Meanchey province has drastically increased despite the lack of adequate infrastructure, including basic amenities such as drinking-water supply. To improve the access to drinking water, governmental and aid agencies have focussed on drilling shallow boreholes. The use of groundwater for irrigation is also a growing concern to cope with the occasional late arrival of the rainy season or to produce food during the dry season. Since the groundwater resource in the province has not been documented, a 4-year study was undertaken (2011–2014), aiming to estimate the capability of groundwater to supply domestic needs and supplementary irrigation for rice production. Aquifer properties were estimated by combined use of hydrogeological techniques with the geophysical magnetic resonance sounding method. Groundwater storage and recharge were estimated based on new developments in the application of the geophysical method for quantifying specific yield. The median groundwater storage of the targeted sandstone aquifer is 173 mm, the recharge is diffuse and annually ranges from 10 to 70 mm, and the transmissivity is low to medium. Simulations of pumping indicate that the aquifer can easily supply 100 L of drinking water per capita daily, even considering the estimated population in 2030. However, the shallow aquifer can generally not deliver enough water to irrigate paddy fields of several hectares during a 2-month delay in the onset of the monsoon.