| 摘要: | 本研究自2012年8月至2013年6月，於大屯火山群地區，分析雨水、地表水與地下水的氫氧同位素組成，藉由各水體的氫氧同位素組成之特徵，探討各水體在時序與空間上的變化，並輔以地下水水位與水溫資料，推估區域地下水之流向。研究結果顯示，地表水的氫氧同位素組成，在夏季較輕冬季較重，顯示地表水受到不同氣團的影響，而地下水的氫氧同位素組成，在夏季較重冬季較輕，呈現與地表水相反的趨勢，表示本研究區域之地表水對地下水的補注機制並不快速。綜合氫氧同位素與地下水水位的觀測資料，在研究區域中，可以將大屯火山地區的淺層地下水分成兩大區塊：北磺溪與南磺溪流域，北磺溪流域的地下水流向大致上由南向北流，而南磺溪流域大致為北往南流。地下水水位的觀測資料顯示，位於北磺溪流域的地下水井，其補注季節約為冬季，而位於南磺溪流域的地下水井，其補注季節約為夏季，因此使得北磺溪流域的地下水氫氧同位素組成重於南磺溪流域。
Over 200 water samples including rain water, surface water and groundwater from August 2012 to June 2013 in the Tatun volcano group were collected and analyzed. The groundwater levels and temperature were integrated with oxygen and hydrogen isotope data to construct the local groundwater flow path and to delineate groundwater watersheds of the region. Two distinct groundwater watersheds were classified, the Northern and Southern Sulfur creek, accordingly. The results show that the isotope composition of surface water are enriched in winter and depleted in summer, indicating that the source of water vapor in summer and winter are different. The seasonal variations of hydrogen and oxygen isotope composition of groundwaters are significant different from surface water. This indicates that it takes much longer to have the rain water become groundwater. The main recharge season of groundwater in northern Sulfur creek watershed is winter while summer is the main recharge season of groundwater in the southern Sulfur creek watershed. Therefore the isotope composition of groundwater in northern Sulfur creek watershed are generally enriched than in southern Sulfur creek watershed. |
