Chen Xuekai, Liu Xiaobo, Peng Wenqi, Dong Fei, Chen Quchang, Sun Yanli, Wang Ruonan
State Key Laboratory of Simulation and Regulation of River Basin Water Cycle, China Institute of Water Resources and Hydropower Research, Beijing 100038, PR China; Department of Water Environment, China Institute of Water Resources and Hydropower Research, Beijing 100038, PR China.
State Key Laboratory of Simulation and Regulation of River Basin Water Cycle, China Institute of Water Resources and Hydropower Research, Beijing 100038, PR China; Department of Water Environment, China Institute of Water Resources and Hydropower Research, Beijing 100038, PR China.
Sci Total Environ. 2019 Apr 1;659:746-755. doi: 10.1016/j.scitotenv.2018.12.013. Epub 2018 Dec 4.
Increasing shrinkage and salinization is occurring in China's inland lakes. Lake Chenghai is located in the southwestern plateau of China and it is one of only three lakes in the world where Spirulina is found naturally, which has experienced severe decline in water level in recent decades (especially between 2006 and 2016). In addition, in China, there is a lack of hydrological observation data collected for many of the similar plateau inland lakes, which has led to a research gap regarding water-salt balance. This study aimed to investigate the lake water-salt balance, identify the causes for the decline in water volume and the adverse effects of the transition of a freshwater lake to a saline lake. A coupled water-salt balance mathematical model of the lake was constructed to gain insight into inland water-salt variation in this data scarce region. For Lake Chenghai, there was a 6.43-m decline in water level with an average rate of decrease of 7.0 cm a between 1970 and 2016; the multi-year average water shortage was 2945 × 10 m a from 2006 to 2016. The variation in the water level was positively correlated with precipitation (R = 0.81, P < 0.0001) and surface runoff inflow (R = 0.76, P < 0.0001) during the wet season, and it was negatively correlated with evaporation (R = 0.71, P < 0.0001) during the dry season. The warm, dry climate in the dry, hot valley area may be the main reason for the decline in the lake level. Changes in water volume and lake salinity affected the presence and abundance of phytoplankton species and the pH of the aquatic ecosystems. The developed methodology can be used to predict the long-term water and salinity evolution of inland lakes to support sustainable water resource planning in data-scarce regions.
中国内陆湖泊的萎缩和盐碱化现象日益严重。程海湖位于中国西南高原，是世界上仅有的三个天然生长螺旋藻的湖泊之一，近几十年来（尤其是2006年至2016年期间）水位急剧下降。此外，在中国，许多类似的高原内陆湖泊缺乏水文观测数据，这导致了水盐平衡方面的研究空白。本研究旨在调查湖泊水盐平衡，确定水量下降的原因以及淡水湖向盐湖转变的不利影响。构建了湖泊水盐平衡耦合数学模型，以深入了解这个数据匮乏地区的内陆水盐变化情况。对于程海湖，1970年至2016年期间水位下降了6.43米，平均下降速率为每年7.0厘米；2006年至2016年期间多年平均缺水量为2945×10立方米/年。雨季水位变化与降水量（R = 0.81，P < 0.0001）和地表径流流入量（R = 0.76，P < 0.0001）呈正相关，旱季与蒸发量（R = 0.71，P < 0.0001）呈负相关。干热河谷地区温暖干燥的气候可能是湖泊水位下降的主要原因。水量和湖泊盐度的变化影响了浮游植物种类的存在和丰度以及水生生态系统的pH值。所开发的方法可用于预测内陆湖泊的长期水盐演变，以支持数据匮乏地区的可持续水资源规划。
