Seasonal variation of the isotope and hydrochemical characteristics of the main lake rivers in Lake Ebinur, Xinjiang

通过野外调查取样和室内测试分析,利用水文化学以及氢氧稳定同位素技术,分析艾比湖主要入湖河流氢氧同位素及水化学的组成特征,并探讨其季节性变化.结果表明:地表水水质指标高值多出现于博乐市、温泉市和精河县及艾比湖湿地附近,主要污染为水体富营养化、工矿业污染以及有机质污染,其污染程度夏、秋季高于春、冬季.河水的δ¹⁸O与δ²H存在明显的线性关系,其相关指数为夏季(R²=0.99) > 春季(R²=0.98) > 秋季(R²=0.96) > 冬季(R²=0.90),均沿当地大气降水线分布,受西北干旱区强烈的蒸发作用影响,各季节河流斜率均小于8,氘过量参数值多为正值.博尔塔拉河与精河地表水体δ¹⁸O值整体上表现为沿流程逐渐偏正的趋势,博尔塔拉河水体氢氧同位素与高程相关指数表现为春季(R²=0.70) > 冬季(R²=0.57) > 夏季(R²=0.45) > 秋季(R²=0.30),精河因其海拔差异不大,流程简短,与高程相关性低.博尔塔拉河和精河氢氧同位素与氯化物、硫酸盐、五日生物需氧量等指标间存在相关性,且在夏、秋季最大,相关系数R>0.75,与总磷、Cu²⁺、色度、浊度等指标基本都不显著相关,相关系数R<0.25.;The important exposition of 'green mountains and clear water are as good as mountains of gold and silver' shows that Chinese leaders attach importance to ecological environment construction. The study on the healthy and sustainable development of lakes in the arid region of Northwest China, where is short of water resource and is of a fragile ecological environment. It is an indispensable part of constructing the harmonious development of economy and environment in China. As a typical closed lake in arid area of Xinjiang, Lake Ebinur is the lowest discharge datum in this area. The unique water cycle makes it highly sensitive to climate change and human activity. In recent years, with the further large-scale exploitation of water and soil resources in the Lake Ebinur wetland and the abundant supply rivers, the ecosystem of the Jinghe River Basin has been seriously disturbed, for example, the desertification and salinization are obviously intensified, and the ecological environment is deteriorating day by day. Therefore, maintaining the water quality of the river into the lake has become an important means to maintain the water balance and the ecological environment of the Lake Ebinur. This paper made an in-depth study of mainly rivers in the Lake Ebinur Basin on October 2016, March 2017, May and July. The characteristics of hydrochemistry and hydrogen and oxygen isotopes are systematically studied. The results show that most high value of water quality indicators appeared in Bole, Wenquan, Jinghe County and near the Lake Ebinur. The main pollution is from water eutrophication, industrial and mining industry and organic matter. The pollution degree in summer and autumn is higher than that in spring and winter. There is obvious linear relationship between δ¹⁸O and δ²H, and its coefficient was as follows:summer (R²=0.99) > spring (R²=0.98) > autumn (R²=0.96) > winter (R²=0.90). The distribution of water line along the local atmosphere. Influenced by the strong evaporation of the northwest arid region, the slope of the rivers in each season is less than 8, and the d-excess value is positive. The value of δ¹⁸O in Bortala and Jinghe River shows a trend of gradual deviation along the flow. The index of correlation between hydrogen and oxygen isotopes in Bortala River and height is that spring (R²=0.70) > winter (R²=0.57) > summer (R²=0.45) > autumn (R²=0.30). The correlation between δ¹⁸O and elevation in Jinghe River is low due to the small difference in altitude and short process. The hydrogen and oxygen isotopes of Bortala River and Jinghe River were correlated with chloride, BOD₅ and so on. The correlation coefficients (R) was higher than 0.75 in summer and autumn.