Assessment of Basin Groundwater Recharge and Mapping Recharge Potential Zone

• Main Authors: Po-Hsun Chang, 張伯勳
• Other Authors: Cheng-Haw Lee
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/30769053991055379817

碩士 === 國立成功大學 === 資源工程學系碩博士班 === 95 === Water resources in Taiwan are unevenly distributed spatially and temporally. Due to the industrial development of Taiwan in recent years and the rise of people’s standard of living the demand for groundwater resource development is growing with each passing day. Over-exploitation has resulted in the decline of groundwater levels and land subsidence. Therefore, the assessment of the potential zone of groundwater recharge is an extremely important topic in proper management of groundwater systems. The main purpose of this thesis is to assess the groundwater recharge and to map recharge potential zone in the Chih-Ben and Jin-Lun creek basin. First, a water balance concept in this study is applied to establish the basin hydrologic model in order to estimate the amounts of precipitation, surface runoff, evapotranspiration, and groundwater recharge in the basin. Moreover, the results of groundwater recharge from the unit grids calculate method is compared the result from Taiwan the groundwater resources map by the Water Resource Agency (2003).The results show the amount of annual groundwater recharge by using water balance model in Chih-Ben and Jin-Lun creek basin is 609.2 mm/yr and 600.5 mm/yr, respectively, and by using unit grids calculate method is 579.9 mm/yr and 567.3 mm/yr, respectively. The relative error of annual groundwater recharge between water balance model and unit grids calculate method in Chih-Ben and Jin-Lun creek basins is 4.8％ and 5.5％, respectively. According to the distribution map of the groundwater recharge, the zone of the groundwater recharge can be shown in upstream region of both basins. In order to assess the groundwater potential zone, the technologies of remote sensing and Geographical Information System (GIS) are applied to integrate five contributing factors including lithology, land cover/land use, lineaments, drainage, and slope. By the way, the weight values of the groundwater recharge were determined by the influencing factors such as aerial photos, geology map, database of the land use, and field verification etc. The resultant map of the groundwater potential zone reveals that the highest recharge potential area is located towards the downstream regions in the Chih-Ben creek basin. This is because gravelly sand and agricultural land with the highly infiltration rate are dominated. On the other hand, the moderate recharge potential area is located at upstream regions due to the limestone with moderate infiltration rate. In the Jin-Lun creek basin, the highest recharge potential area is located towards the downstream regions because of lithology and land cover/land use.