应用氢氧稳定同位素分析地下水补注之研究AStudyonGroundwater.PDFVIP

應用氫氧穩定同位素分析地下水補注之研究 A Study on Groundwater Recharge by Hydrogen and Oxygen Stable isotopes 1 2 3 4 ＊ 簡銘成 杜永昌 汪中和 丁澈士 1.國立屏東科技大學土木工程系碩士 2.國立屏東科技大學坡地防災暨水資源工程研究所博士班 3.中央研究院地球科學研究所研究員 4.國立屏東科技大學土木工程系教授 摘要 本研究目的為應用氫氧穩定同位素分析林邊溪流域之地下水各補注來源比例，並推估 2006 年林邊溪流域之地下水總補注量。研究結果顯示林邊溪流域 2006 年之地下水年補注量約為 4.6 億立方公尺，年抽水量與流失量總合約為 4.1億立方公尺，除部份沿海地區外，整體來說未超抽。 林邊溪流域之地下水補注源經由氫氧同位素質量平衡分析後，發現受降雨直接補注的比例，以含 18 18 水層 F1最高 (δ O = 16% 、δD = 19%) ，F3最低 (δ O = 9% 、δD = 7%) ；受山區側向補注之比例以 18 18 F3最高 (δ O = 91% 、δD = 93%) ，F1最低 (δ O = 84% 、δD = 81%) ，顯示林邊溪流域深層含水層 之地下水補注受山區河水之補注效應較明顯，而在淺層含水層則是以降雨直接補注較明顯。 關鍵字：林邊溪、地下水補注、地下水流向、氫氧穩定同位素 The purposes of this research are to analyze the correlation of the compositions of hydrogen and oxygen stable isotopes in groundwater recharge sources; and then to estimate the total groundwater recharge amount in Lin Bian River basin as well as its flow direction for the year 2006.The annual groundwater recharge amount in Lin Bian River basin is estimated as about 460 million cubic meters in 2006. The total annual water extraction amount plus the water loss is estimated as about 410 million cubic meters; thus, these two parameters are within the extraction allowance, except for some coastal areas According to the hydrogen and oxygen isotopic mass balance analyses of the groundwater recharge sources in Lin Bian River basin, the aquifer F1 has the highest (δ18O = 16% 、δD = 19%) and F3 has the lowest (δ18O = 9% 、δD = 7%) proportions of rainfall recharge, respectively. On the other 18 18 hand, F3