内蒙桌子山地区凝结水对岩溶地下水补给的探讨

内蒙古桌子山区为西北干旱地区,平均年降水量不足200mm。区内中、下奥陶统碳酸盐岩中岩溶水是当地重要供水水源。该区岩溶地下水氢氧同位素关系图表明,其样点基本分布在当地雨水线左上方,存在明显的反向“氧漂移”现象,这种现象在作者所见到我国北方多数岩溶泉域岩溶地下水的同位素分布是唯一的。通过本区特定的气候、水文地质条件以及自然条件分析认为,本区岩溶地下水中可能存在凝结水的补给,这一观点在2004年8月30日清晨的露水同位素取样分析后得到了进一步支持。 

DISCUSSION ON CONDENSED WATER SUPPLY TO KARST GROUNDWATER IN ZHUOZI MOUNTAIN REGION, INNER MONGOLIA

The Zhuozi Mountain area of Inner Mongolia is an arid region in the northwest of China.The average annual precipitation is less than 200 mm.The middle and lower Ordovician carbonate rock karst water-bearing stratum in the district is important resource of water supply.Oxyhydrogen isotope relationship curve in the region indicates that the samples basically distribute in the upper left of local rainwater line and an obvious phenomenon of reverse "Oxygen drifting"exists.This kind of isotope distribution is the only one in the most karst groundwater in northern karst spring area that the authors have ever studied. From the particular climate,hydrogeological and natural conditions in this district it can be concluded that there might be condensed water supply to karst groundwater in this area.This point of view was evidenced by analysis of dew isotope.