小流域降雨径流氢氧同位素特征分析及其对径流分割的指示意义  

Characteristics of hydrogen and oxygen isotopes in rainfall-runoff in small watershed and their implications for runoff separation

作　　者：王轶凡[1,2] 瞿思敏[1,2] 李代华[3] 石朋[1,2] 单帅[1,2] 周敏敏[1,2] 刘金涛[1,2] 韩小乐[1,2] 

机构地区：[1]河海大学水文水资源与水利工程科学国家重点实验室,江苏南京210098 [2]河海大学水文水资源学院,江苏南京210098 [3]云南省水文水资源局文山分局,云南文山663099

出　　处：《河海大学学报（自然科学版）》2017年第4期365-371,共7页Journal of Hohai University(Natural Sciences)

基　　金：国家自然科学基金(41371048;51479062;40901015);国家重点研发计划(2016YFC402703)

摘　　要：结合水文气象资料,分析浙江和睦桥小流域在2015年汛期的3场台风雨事件中降雨、地面径流以及河水的氢氧同位素组成,并研究降水中δ~2H-δ^(18)O的相关关系。结果表明,降雨中的氢氧同位素具有显著的时程效应。无论是等体积的降雨增量还是等时段降雨,随着降雨历时的增加,δ^(18)O值均出现递减的趋势;穿透降雨由于林冠的滞留作用以及同位素分馏作用,比林外降雨更加富含重同位素;降水是河水的主要补给来源,由于河水蒸发,河水中重同位素比同时期降雨和地面径流更加富集。Based on hydrological and meteorological data, the composition of hydrogen and oxygen isotopes in precipitation, surface water, and stream water were investigated for three typhoon events in the flood period of 2015 in the Hemuqiao Watershed, and the δ2H-δ1SO relationship in precipitation was studied. The results show that the composition of hydrogen and oxygen isotopes in precipitation exhibited significant temporal variation. With the increase of the duration of rainfall, the δ18O values of the incremental rainfall with the same volume and rainfall during the same period had a decreasing trend. Throughfall, rather than rainfall, enriched heavier isotopes because of the canopy storage and isotopic fractionation. Rainfall was the main supply source of stream water. The contents of heavy isotopes in stream water were more abundant than those in precipitation and surface runoff due to the evaporation of stream water.

关 键 词：氢氧同位素 大气降水 地面径流 河水 时程效应 小流域 东苕溪水系 

分 类 号：P338[天文地球—水文科学]