Evaporation dominates the loss of plateau lake in Southwest China using water isotope balance assessment

Yajun Wang; Ronghua Du; Xiaofeng Cao; Hongwei Yu; Yan Xu; Yilei Yu; Jianfeng Peng

doi:10.1016/j.scitotenv.2023.162415

Evaporation dominates the loss of plateau lake in Southwest China using water isotope balance assessment

Sci Total Environ. 2023 May 15:873:162415. doi: 10.1016/j.scitotenv.2023.162415. Epub 2023 Feb 21.

Authors

Yajun Wang¹, Ronghua Du², Xiaofeng Cao³, Hongwei Yu⁴, Yan Xu⁵, Yilei Yu⁶, Jianfeng Peng⁷

Affiliations

¹ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
² Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, Jiangsu Province 214122, China.
³ Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
⁴ State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
⁵ College of Marine Science and Technology, China University of Geosciences, Wuhan 430074, China.
⁶ Xiong'an Institute of Innovation, Chinese Academy of Sciences, Xiong'an 071899, China. Electronic address: yuyilei@xii.ac.cn.
⁷ Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: pengjf@mail.tsinghua.edu.cn.

PMID: 36822415
DOI: 10.1016/j.scitotenv.2023.162415

Abstract

The water balance budget in remote plateau lakes provides a fundamental information on the local climate-hydrological pattern. However, integrated investigation on the waters entering the lake, especially groundwater, was limited. To assess the current climate stress on Yunnan-Guizhou Plateau lakes, we collected rivers, groundwater, lake, and precipitation with varying isotopic compositions in the Chenghai Lake basin over four separate campaigns during a hydrological year. The wide and enriched variation of isotope composition in rivers, groundwater, and lake indicate that they have undergone distinct evaporations, which further reveal the recharging and mixing processes. Based on the similar isotopic signals between rivers and precipitation, rivers can serve as proxies for precipitation. Groundwater was primarily replenished by high mountain precipitation duo to the stable isotopic values in aquifers. Even through mass water in lake was able to smooth out some variability, the considerable isotopic variation of lake during the four collections suggested the influence of meteorological conditions. According to the assessment of isotope balance model, lake evaporation accounts for almost 65 % of the total inflow for one year, which partially explains the climate stress on the lake level. As the most sensitive variables, changes in relative humidity (h) and isotope composition of atmospheric moisture (δ_A) resulted in remarkable variations in E/I ratios and the constructed water isotope framework. These results shed light on the capacity of evaporation relative to lake input and provide interpretations on local paleoclimate and predicted-climate construction.

Keywords: Chenghai Lake; Evaporation-to-inflow ratio; Hydrological year; Isotopic characteristics; Water mass balance.