A Study of Climate Change Impact on Groundwater Recharge by SWAT Simulation Model

The slopeland disaster caused by excessive groundwater recharge has been widely discussed, but only few studies have addressed whether the occurrence of slopeland disaster is exacerbated by the rise of groundwater recharge due to changing rainfall pattern. Landslide disasters happen because of shear strength reduction with high soil moisture, which is resulted in percolation caused by surplus infiltration. This study aims to analyze the impact of groundwater level on slopeland disaster under climate change, which Soil Water Assessment Tool (SWAT) is adapted to simulate groundwater recharge. By applying baseline and the future rainfall data downscaled from General Circulation Models (GCMs), the potential impact of slopeland disaster of selected study area, Nanshi river basin, New Taipei City, Taiwan, could be predicated.landslide disasters happen because of shear strength reduction with high soil moisture .The study simulates groundwater recharge based on baseline and future rainfall in the basin of Nanshi River, New Taipei City,Taiwan. The potential impact of slopeland disaster may also be predicated from the outcome of this research. The research method of was based on the hydrological theory, by analyzing and calculating SWAT and geographic factors database that has been established at the field. In terms of hydrologic factors, the historical observance of rainfall from Fushan station as well as the future data from GCMs (General Circulation Models) were the input data to simulate baseline and future groundwater recharge. The results indicate the similarity in total precipitation between current and future scenarios, but significant alterations in the rainfall pattern (i.e. increasing extreme heavy rainfall), which leads to the increment in waterground level. The raising waterground level, then, increases the risk of slopeland disaster in Nanshi river basin. Consequently, this study not only serves as a guide for further research on slopeland disaster, but also provides the reference for the design of soil conservation structures to meet the future climate.