文献类型：期刊文献

英文题名：Differences in watershed evaporation indicated by hydrogen and oxygen single and dual isotopes: Evidence from controlled simulation tests under different land uses

作者：Hu, Yundi Fan, Hongdai Zhao, Min Hu, Deyong Bao, Qian Zeng, Cheng Li, Dong Zhang, Yi Xia, Fan Cai, Xianli Chen, Jia Zhou, Zhongfa

第一作者：Hu, Yundi

通信作者：Hu, YD[1];Zhou, ZF[1]

机构：[1]Guizhou Normal Univ, Sch Geog & Environm Sci, Guiyang 550025, Peoples R China;[2]State Key Lab Incubat Base Karst Mt Ecol Environm, Guiyang 550025, Peoples R China;[3]Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang 550081, Peoples R China;[4]Chinese Acad Sci, Puding Karst Ecosyst Res Stn, Chinese Ecosyst Res Network, Puding 562100, Peoples R China;[5]Guizhou Bur Geol & Mineral Explorat & Dev, 105 Geol Team, Guiyang 550018, Peoples R China;[6]Sichuan Normal Univ, Key Lab Land Resources Evaluat & Monitoring Southw, Minist Educ, Chengdu 610066, Peoples R China;[7]Guizhou Inst Technol, Sch Resources & Environm Engn, Guiyang 550025, Peoples R China

第一机构：Guizhou Normal Univ, Sch Geog & Environm Sci, Guiyang 550025, Peoples R China

通信机构：corresponding author), Guizhou Normal Univ, Sch Geog & Environm Sci, Guiyang 550025, Peoples R China.

年份：2023

卷号：617

外文期刊名：JOURNAL OF HYDROLOGY

收录：;EI(收录号：20230513471188);Scopus(收录号：2-s2.0-85146972971);WOS:【SCI-EXPANDED(收录号:WOS:000926256900001)】；

基金：This work was supported by the National Natural Science Foundation of China (42072278, 42177248, 42161048 and 41807366) , the Guizhou Science and Technology Supporting Plan (No. 2020-4Y013) and funding from Guizhou Normal University ( [2021] 26) .

语种：英文

外文关键词：Watershed evaporation; Hydrogen and oxygen isotopes; Dual isotopes; D -excess; Lc -excess; Land use

摘要：Partitioning watershed evapotranspiration into evaporation and transpiration is essential for studying the water-carbon cycle, and the key step in this partitioning is to calculate watershed evaporation based on isotopic indexes. The 818O and 82H single isotopes and d-excess or lc-excess dual isotopes derived from 818O and 82H are widely used for this purpose. Although 818O, 82H, and d-excess have different characteristics, few studies have assessed how these differences influence the usefulness of these isotopes as indicators of watershed evaporation. Here, we simulated five watersheds with different land uses and degrees of evaporation in a region of Southwest China with a subtropical monsoon climate. We then investigated differences in the ability of the isotopic indexes to indicate watershed evaporation over two hydrological years. We found that d-excess and lc-excess dual isotopes were better indicators of watershed evaporation than 818O and 82H single isotopes. This is because the 818O and 82H in precipitation are easily influenced by rainout during the rainy season, when groundwater is primarily recharged. They are more variable than d-excess and lc-excess, which leads to 818O and 82H in groundwater being more sensitive to changes in the isotopic signal input in precipitation. This probably interferes with, or even masks watershed evaporation signals carried by 818O and 82H. The annual mean isotopic compositions were more depleted in groundwaters (818O = - 8.7 %o to - 8.5 %o, 82H = - 61.9 %o to - 58.7 %o) than in precipitation (818O = - 8.3 %o, 82H = - 54.3 %o) from November 2015 to October 2016; these compositions fail to support the isotopic enrichment of groundwater compared with that of precipitation. Evaporation rates over two years derived from d-excess dual isotopes agreed well with those from the water balance in bare-rock and bare-soil lands, which had no data from plants available for verification. Compared with hydrogen and oxygen single isotopes, their dual isotopes reflected watershed evaporation more accurately, especially in Asian monsoon regions.