| Summary: | 碩士 === 國立中央大學 === 應用地質研究所 === 101 === Recent groundwater quality monitoring data show that the total dissolved solids and arsenic ions concentrations in many of Kaohsiung plain areas are higher than that of drinking water standards. This study uses DRASTIC model to create groundwater vulnerability maps for the Kaohsiung plain area. The analytic hierarchy process (AHP) was employed to modify the DRASTIC weightings to improve the prediction accuracy of the DRASTIC model. Based on the modified DRASTIC model this study then uses MODFLOW model to evaluate the groundwater vulnerability induced by pumping events. The DRASTIC model results show that the medium high to high groundwater vulnerability (140 ≤ DI ≤ 180) areas for Kaohsiung plain are Daliao, Dashu, and Lin Yuan districts. The low to medium groundwater vulnerability (102 ≤ DI ≤ 120) areas are near Tianliao, Qishan and Mino districts. The AHP modified model results show that the correlation of vulnerability maps are improved significantly from 23% to 72.5%. The results of MODFLOW model show that the large pumping rates will lead to 3 m drawdown in average near the Tashe, Ren Wu, Lin Yuan, and Dashu districts. However, the different aquifer materials in these areas will either decrease (Tashe, Ren Wu, and Lin Yuan districts) or increase (Dashu district) the groundwater vulnerability. The average increase of groundwater vulnerability in the Kaohsiung area is about 8% and the high vulnerability areas are mainly located in southwest regions in the Kaohsiung plain.
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