在屏東平原只有約一半的人使用自來水，遠低於台灣的自來水平均普及率93.91％，大量的地下水作為水資源以供應家庭、農業灌溉、水產養殖及畜牧工業等需求。屏東平原的長期地下水質調查顯示，部分地區地下水明顯已污染，因此規劃完善的屏東平原地下水水質保護計劃是必要工作。當土地利用產生的有害化學物質可能入滲到非飽和土壤(Unsaturated soil)中，最終會到達下面的非受壓含水層，因此，淺層含水層的地下水水質易受到土地利用的影響。本研究目的在於探討屏東平原土地利用與地下水質的相關性，應用因子分析分析46口監測井中的14項地下水質參數，及井周圍鄰近組成面積百分比之9項土地利用類別與4項地質材料之厚度。分析結果指出因子一中水利用地與導電度、硫酸鹽、氯鹽、鈉、鉀、鈣及鎂有正相關；因子二顯示果樹區與硝酸鹽氮為負相關，但與鹼度呈現正相關；因子三指出廢耕地與總有機碳及砷呈現負相關；而因子四顯示養殖用地與鐵及錳呈現負相關。依據因子得分圖，可優先考慮相對高污染潛在地區以便規劃土地利用管理及地下水質監測，評估當前的土地利用做法，採取新措施更好地預防或控制地下水污染。;In the Pingtung Plain only approximately half of residents use tap water while the average tap water coverage in Taiwan is 93.91 %. A substantial amount of groundwater is used as a source of water to meet drinking, agriculture and aquaculture requirements. A long-term groundwater quality survey in Pingtung Plain has revealed obvious contamination of the groundwater in some area, with several measured groundwater quality parameters in excess of the level recommended by the Taiwan Environmental Protection Administration. Thus, establishing a sound plan for groundwater quality protection in Pingtung Plain is imperatively important. The harmful chemicals coming from inappropriate land use permeate through unsaturated soil and ultimately reach the underlying unconfined aquifer system. Groundwater quality in shallow aquifer is thus significantly affected by the land use. This study targets to characterize the relationship between land use and groundwater quality in Pingtung Plain. The goal is achieved by application of the factor analysis method to analyze the 14 water quality parameters at 46 monitoring wells, the area percentage for 9 land use categories in the neighborhood of the wells, the length for 4 soil types. The results show that the water conservation was associated with electrical conductivity, sulfate, chloride, sodium, potassium, calcium and magnesium. Fruit Farm was associated with nitrate and alkalinity. Uncultivated land was associated with total organic carbon and arsenic. Aquaculture was associated with iron and manganese. According the map of factor scores to describe the areas that are more vulnerable to contamination from land use and prioritize the areas where more intensive monitoring might be needed, as well as evaluating current land use practices, or adopting new measures to better prevent or control groundwater pollution.
