艾比湖流域是西北地区重要的生态屏障,维持着该地区乃至整个新疆北部的生态平衡.艾比湖流域水环境的好坏关系着当地经济和流域的可持续发展.然而,针对艾比湖流域长期水质变化、营养状况和健康风险的研究较少,故基于艾比湖流域2005—2020年12个断面长时间序列的监测数据,利用加拿大水质指数(Canadian water quality index,CWQI)评价河湖水质状况,采用综合营养状态指数(comprehensive trophic level index,TLI (∑))评价艾比湖水体富营养化状态,使用Risk评价水环境健康风险(water environment healthy risk,WEHR),并结合逐步多元线性回归(SMLR),分析了水质参数与CWQI、TLI(∑)与WEHR之间的关系.结果表明:(1)精河CWQI下游大于上游,而博尔塔拉河相反,且精河与博尔塔拉河均存在点源污染,精河CWQI的变化范围46.29~98.71,博尔塔拉河CWQI的变化范围25.36~99.71,艾比湖CWQI的变化范围42.29~55.95,变异系数介于0.01~0.23之间;(2)2005—2020年艾比湖水体TLI (∑)大多数介于轻度富营养和中度富营养状态之间;氮磷比表明,研究区为磷限制状态,主要受农业面源污染、放牧、生活废水等人为活动的影响;(3)精河WEHR上游大于下游,而博尔塔拉河相反.水环境健康风险主要受化学致癌物影响,砷(As)的影响最大,其次为六价铬(Cr<sup>6+</sup>).各断面点总风险超过美国环境保护署(United States Environmental Protection Agency,USEPA)规定的最大可接受风险水平;(4)逐步多元线性回归分析表明,影响水质的参数有高锰酸盐指数(COD<sub>Mn</sub>)、氨氮、总磷(TP)、总氮(TN)、大肠菌群(E.coli)、透明度和挥发酚(volatile phenol,VP),影响水体富营养化参数为COD<sub>Mn</sub>、TP、TN,影响WEHR的参数为氟化物(F<sup>-</sup>)、铜(Cu)、砷(As)、镉(Cd)、六价铬(Cr<sup>6+</sup>)、铅(Pb)、氰化物(Cyanide)和挥发酚(VP).本文的研究结果可为区域水环境可持续发展和水资源的合理配置提供有力的科学依据.;Lake Ebinur Basin is an important ecological barrier in Northwest China, maintaining the ecological balance of the region and even the whole northern Xinjiang Province. The water environment of Lake Ebinur Basin is closely related to the local economy and the sustainable development of the basin. However, there are few studies on long-term water quality change, nutritional status and health risk. Therefore, this paper is based on the long time-series monitoring data of 12 sections in Lake Ebinur Basin from 2005 to 2020. The water quality of rivers and lakes was evaluated by the Canadian water quality index (CWQI), the eutrophication status of Lake Ebinur was evaluated by the comprehensive trophic level index (TLI(∑)), and the water environment health risk (WEHR) was evaluated. Combined with stepwise multiple linear regression (SMLR), the relationships between water quality parameters and CWQI, TLI(∑) and WEHR were analyzed. The results show that:(1) The CWQI of Jing River in the lower reaches is larger than that in the upper reaches, while that in Bortala River is opposite, and there is point source pollution both in Jing River and Bortala River. The CWQI of Jing River ranges 46.29-98.71, Bortala River 25.36-99.71, Lake Ebinur 42.29-55.95, respectively, and the coefficient of variation ranges from 0.01 to 0.23; (2) The TLI(∑) of Lake Ebinur from 2005 to 2020 is between mild and moderate eutrophication; the ratio of nitrogen to phosphorus shows that the study area is phosphorus limited; (3) The WEHR in the upper reaches of Jing River is larger than that in the lower reaches, while that in Bortala River is opposite. The health risk of the water environment is mainly affected by chemical carcinogens, As is the most important, followed by Cr<sup>6+</sup>. The total risk of each section exceeds the maximum acceptable risk level specified by the United States Environmental Protection Agency (USEPA); (4) Stepwise multiple linear regression analysis showed that COD<sub>Mn</sub>, NH<sub>3</sub>-N, TP, TN, E. coli, SD (secchi depth) and VP (volatile phenol) affected water quality, COD<sub>Mn</sub>, TP and TN affected water eutrophication, and F<sup>-</sup>, Cu, As, Cd, Cr<sup>6+</sup>, Pb, cyanide and VP affected WEHR. The results of this study can provide a strong scientific basis for the sustainable development of the regional water environment and the rational allocation of water resources.
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