摘要:
通过对重庆市北碚区大气降水和马鞍溪上游龙滩子水库水的氢氧同位素进行的一个水文年(2014年)的样品采集监测,研究了降水与水库的水的氢氧同位素之间的变化特征和规律。结果表明:(1)北碚区大气降水线方程为δD=8.82δ18 O+18.97,r=0.99,n=101,P <0.01,δD、δ18 O 相关性极为显著,该区大气降水线斜率和截距大于全球大气降水线和中国大气降水线,表明研究区主要受西南季风和东南季风双重影响所致;(2)大气降水中δD、δ18 O 具有明显的季节变化,夏半年偏负,冬半年偏正;(3)大气降水中的δD、δ18 O 与降水量及温度呈现负相关关系,降水量效应显著,并且该效应远远掩盖了温度效应;(4)水库中水的δD、δ18 O 具有极好的相关性,其δD、δ18 O 样点落于全球大气降水线和区域大气降水线附近,并且水库中水 d 的变化趋势与降水 d 基本一致,表明前者主要补给来源是降水,而水库中水的δD、δ18 O 和 d 的变化幅度远远小于降水,表明前者不仅受降水补给,还受土壤水和地下水的补给。
Abstract:
The hydrogen and oxygen isotopes of precipitation water in Beibei District of Chongqing and water in Longtanzi reservoir in upper stream Maanxi were investigated during a hydrologic year (2014),to explore the relationship ofδD and δ1 8 O between precipitation and the reservoir water. It was found that the correlation between δD and δ1 8 O in the precipitation is extremely significant, namely,δD=8.82δ1 8 O+18.97,r=0.99,n=101,P <0.01.The slope and intercept of local meteoric water line are both greater than the global meteoric water line and China meteoric water line.The result suggested that southwest monsoon and southeast monsoon have alternative influence on local precipitation;(2)BothδD Dandδ1 8 O values in rain water exhibited significant seasonal variations,having lower values in summer and higher ones in winter;(3)Theδvalue and precipitation as well as temperature assumed negative correlation. The precipitation amount effect of the δD and δ1 8 O in the precipitation was very profound,which concealed the temperature effect;(4)The δD and δ1 8 O in reservoir had a great correlation and they fell near the global meteoric water line and local meteoric water line.In addition,the excess deuterium (d)in the reservoir wa-ter and in the precipitation showed very similar patterns.The result indicated that the precipitation recharged the reservoir.However,the variety range of theδD andδ1 8 O from reservoir was far less than precipitation. The result suggested that the reservoir was not only recharged by precipitation,but also by soil water and groundwater.
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