Author(s): O. Kamnoet; C. Chinnarasri
Linked Author(s):
Keywords: SWAT model; Climate scenario; Water use scenario; Spatial analysis; Land use change
Abstract: To develop a proper water resources management in a watershed, it is necessary to investigate the hydrological processes interacting with the physical characteristics and trend of climate change in the watershed. Klongyai basin, a small tropical watershed in Rayong Province of Thailand, was selected for the case study. To simulate the hydrological processes in the basin, the SWAT model was calibrated and validated using measured streamflow data collected at a stream gauge located on the Klongyai basin. Thematic maps for the model are digital elevation model (DEM) of 2001, soil series map of 2001, land use map of 2001 and 2006 and drainage network. The period data for calibration and verification processes are 2001–2003 and 2004–2005, respectively. Good agreement between observed and simulated discharge, which was expressed by Nash Sutcliffe efficiency (NSE), was found. In this study, the water availability scenario assumes that average surface temperature and precipitation will change in the future because of climate change. To estimate the future water use, the water use scenarios include assumptions about the trend in the driving forces of water use in the domestic, industrial and agricultural sectors. Three scenarios are investigated, i.e. Scenario I is an intermediate estimate made for changes in water use, while Scenarios II and III contain a set of assumptions that lead to a lower and a higher estimate of water use than Scenario I. By using spatial analysis and displaying the results with GIS and streamflow from SWAT model, the simulation results lead to obtaining the effects of the change in important factors, such as population growth, economic activity, land use and urbanisation and climate change. The availability of water resources and water management practices are proposed and discussed. Some recommendations are given in the results of the study.
Year: 2014