Abstract: “An assessment of groundwater potential in Huaykhunram subdistrict, Phattana Nikhom district, Lopburi province, Central Thailand was conducted. The study area was underlain by a fractured limestone aquifer where groundwater flow regime is complex and difficult to characterize. Groundwater is the main agricultural water source in this area and its quantity must be estimated for better planning of irrigation system. Primary study indicated that agriculture and domestic usage of groundwater in an area of approximately 100 km2 was as large as 1.26 Mm3/yr where the natural recharge and safe yield were approximately 3.89 Mm3/yr. The groundwater is mainly Ca-HCO3 and Ca-Mg-HCO3 water types. The geochemical elements indicate quality of groundwater is controlled mainly by the dissolution of carbonate rocks. Future work will include pumping and tracers test as well as groundwater modeling using MODFLOW-CFP (conduit-flow process) to better assess groundwater resource of this area.”

Keywords: groundwater, limestone, potential, aquifers