竹林流域各水源的同位素特征对降水事件的响应分析

河水与地表蓄水补给来源的确定对于深入理解流域产流机制及流域滞时分布具有重要作用。通过采集2015～2016年和睦桥竹林小流域5场台风雨事件中林外降水、贯穿降水、地表蓄水、河水和土壤水水样并分析其氘氧稳定同位素特征,探究河水和地表蓄水同位素差异及补给水源。结果表明,林外降水相较于贯穿降水同位素偏富集,主要由于蒸发作用对林外降水影响相对较大。地表蓄水和河水稳定同位素组成及氘盈余值接近,同时两者的同位素组成对降水响应不明显,主要可能由深层土壤水和地下水补给,本场降水对河水和地表蓄水补给量很小。

Response Analysis of Isotope Characterstics of Various Water Sources to Rainfall Events in Zhulin Watershed

The determination of recharge source of surface water and streamflow is important to better understand the runoff generation mechanism and distribution of water flow delay times in the watershed. The samples of precipitation, thoughfall, surface storage water, streamflow water and soil water in five typhoon rainfall events during 2015-2016 in Hemuqiao Zhulin small watershed were collected to analyze the stable istopic characteristics of deuterium and oxygen. The isotope data of various water sources were used to determine the recharge source of surface water and streamflow. The isotopic composition of thoughfall was richer than that of precipitation, which indicated that the precipitation experienced strong evaporation. The isotopic composition of surface storage water and streamflow were closed to each other.The response of the isotopic composition of streamflow and surface water to precipitation is insensitive because they are recharged by deep soil water and groundwater.