Estimation of Evaporative Loss of Surface Water Using Stable Isotopes in a Lowland Rice Field, Suphanburi, Thailand
Water scarcity resulting from erratic rainfall pattern is a major problem over the world. As diminishing water resources for agriculture and increasing demand for rice yield, understanding on hydrological cycle is crucial on water management. The loss of water due to evaporation from rivers and canals constitutes a substantial part of useable water. The estimated evaporation loss can be obtained by using the isotope compositions of precipitation and an established local evaporation line. It is recognized a very useful tool in providing a quick and cost effective insight into the water balance of surface water pool. In this study of 2015-2017 in Suphanburi province, the isotopic signatures of precipitation and surface water canal resulted in a local meteoric water line of δ2H = 7.63 δ18O – 1.05 (n = 168, r2 = 0.94) and local evaporation line for surface water creek of δ2H = 5.95 δ18O – 14.42 (n = 155, r2 = 0.90), respectively. The estimated evaporation loss using the Hydrocalculator software indicated that the estimated fractional water loss by evaporation in the surface water canal of Sri Prachan district, Suphanburi was ~12%.
B. Porntepkasemsan et al., "Estimation of Evaporative Loss of Surface Water Using Stable Isotopes in a Lowland Rice Field, Suphanburi, Thailand", Applied Mechanics and Materials, Vol. 886, pp. 8-13, 2019