Hydrogeochemical characteristics of groundwater irrigation in the climate change prone areas of Cambodia

Abstract

This research assesses the hydrogeochemical characteristics of irrigation groundwater to understand its quality within climate change prone areas of Cambodia. Thirteen groundwater samples were collected in Takeo province to analyze for major physicochemical properties. Both pH and TDS were below the maximum permissible limit of drinking water set by the World Health Organization (WHO) and Cambodia’s standard of drinking water quality. The study finds concentrations of cations and anions in order of Na+ > Ca2+ > Mg2+ > K+ and HCO3 > Cl- > NO3- > SO42- > PO43-, wherein four major hydro-chemical facies (Ca-Mg-Cl, Ca-HCO3, Na-Cl and Na-HCO3 types) were identified. Application of the Gibbs diagram showed evaporation and water-rock interaction as the main factors affecting hydrogeochemical properties in the study area. Furthermore, the majority of groundwater samples were classified to be ‘excellent’ and ‘good’ for irrigation purposes, according to the value of residual sodium carbonate (RSC), sodium adsorption ratio, and electrical conductivity. Thus, it can be assumed that the quality of groundwater may be considered suitable for irrigation purpose and agriculture.