Amount of Flow and Peak Discharge Assessment from Climate and Land Use Changes in Mae Klang River Basin, Chiang Mai Province

Abstract

Climate and land use change may cause flooding. This study investigated these changes by applying the HEC-HMS model to evaluate changes in flow volume and peak discharge in the Mae Klang River Basin, located in Chiang Mai Province. Future projections of climate conditions in year 2048, derived from the CCSM4 model under RCP 4.5 and RCP 8.5, along with land use change data, were utilized to forecast future flood risk in the study area. The results showed that from 2007 to 2021, land use changes in woods areas decreased by 2.71%, while impervious areas increased by 0.85%. The results from the future model for 2018 to 2048 in the case of land use change showed that the water volume and peak discharge increased slightly. In the case of climate change, the water volume increased significantly, but the peak discharge decreased by 10.30%. In the case of changes in both land use and climate, the water volume at P.24A increased by 65.80% at RCP 4.5 and 69.03% at RCP 8.5, and the water volume at the outlet increased by 69.56% at RCP 4.5 and 72.73% at RCP 8.5. From the results, climate and land use changes influence the increased water volume, which may be the cause of flooding in Chom Thong District. Therefore, flood monitoring and preparedness should be carried out to prevent future flooding.