How Do Sustainable Development-Induced Land Use Change and Climate Change Affect Water Balance? A Case Study of the Mun River Basin, NE Thailand

Abstract

Thailand has set the 20-year National Strategy (2018–2037) towards sustainable development and building adaptability to climate change. The strategy promotes forestation and higher bioethanol energy demand. This study aims to investigate the effects of the climate and land-use changes on water balance in 2037, the end of the National Strategy, for the Mun River Basin, NE Thailand. The simulated climate dataset used in this study was ensemble means from IPCC AR5 Global Circulation Models for representative concentration pathway (RCP) 4.5 and 8.5 climate scenarios. The land-use change was simulated using the Dyna-CLUE (Conversion of Land Use and its Effects) model. The Soil and Water Assessment Tool (SWAT) was used to assess the water balance (considering evapotranspiration—ET, percolation—PERC, surface runoff—SURQ, and groundwater lateral flow—LATQ). The combined effects could increase monthly ET, whereas the climate change effect could outrun the land-use changes, resulting in increasing PERC. The sustainable development under the National Strategy (2018–2037) could be insignificantly affecting the water balance, whereas the “Bioethanol-Oriented” land-use scenario could increase SURQ and decline LATQ, which could intensify flooding. Soil-water conservation measures are recommended to mitigate the adverse effects of bioenergy.