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.
Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, Jiangsu Province 214122, China.
Sci Total Environ. 2023 May 15;873:162415. doi: 10.1016/j.scitotenv.2023.162415. Epub 2023 Feb 21.
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) 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.
高原湖泊水量平衡预算提供了有关当地气候-水文格局的基本信息。然而，对于进入湖泊的水体，特别是地下水的综合调查是有限的。为了评估当前气候对云贵高原湖泊的影响，我们在一个水文年内的四个不同阶段收集了陈海湖流域具有不同同位素组成的河流、地下水、湖泊和降水。河流、地下水和湖泊中同位素组成的广泛和丰富变化表明它们经历了明显的蒸发作用，这进一步揭示了补给和混合过程。由于河流和降水之间存在相似的同位素信号，因此河流可以作为降水的替代品。由于含水层中稳定的同位素值，地下水主要由高山降水补给。尽管湖泊中的大量水能够消除一些变化，但在四次采集期间，湖水的相当大的同位素变化表明气象条件的影响。根据同位素平衡模型的评估，湖泊蒸发量几乎占一年总流入量的 65%，这部分解释了湖泊水位的气候压力。作为最敏感的变量，相对湿度 (h) 和大气水汽同位素组成 (δ) 的变化导致 E/I 比值和构建的水同位素框架发生显著变化。这些结果揭示了蒸发相对于湖泊输入的能力，并为当地古气候和预测气候的构建提供了解释。
