确定干旱—半干旱地区降水入渗补给量的新方法——氯离子示踪法

在干旱－半干旱地区由于入渗水分大部分滞留在包气带中，强烈地蒸发、蒸作用导致包气带中土壤水的氯离子浓度改变。氯离子示踪方法从质量守恒角度，通过比较土壤水分的氯离子浓度和降水输入的氯离子浓度大小，可以定量确定降水入渗量和降水入渗补给的历史变化过程。本文介绍了目前国外应用较普遍的氯离子均衡法和氯离子累积法，并讨论了方法应用时存在的一些问题。

CHLORIDE TRACER METHOD FOR ESTIMATION NATURAL GROUNDWATER RECHARGE IN ARID AND SEMIARID REGIONS

In arid and semiarid regions,most of the diffuse recharge resides in unsaturated zone,and the forceful evapotranspiration results in the changes of chlorideconcentration in soil water.The chloride tracer method based on the conservation of mass,by making a comparison between the chloride concentration of soil water and that of deposition of precipitation,could be used for estimation local recharge of groundwater and probably analyzing the past recharge conditions.In this paper the chloride balance method and the chloride cumulative method used widely in abroad are introduced,and some limitations of the methods in application are discussed.