State Key Laboratory of Eco-Hydraulics in Northwest Arid Region, Xi'an University of Technology, Xi'an 710048, China.
Shaanxi Han Weihe Water Diversion Engineering Construction Co., Ltd., Xi'an 710086, China.
Int J Environ Res Public Health. 2023 Feb 7;20(4):2890. doi: 10.3390/ijerph20042890.
The water source of the water diversion project from the Hanjiang River to the Weihe River is one of the most important drinking water sources in China. Its water quality is related to the water safety of the long-distance water diversion system from the Hanjiang to Weihe Rivers. In order to explore the spatiotemporal change trend of the water environment characteristics of the water source area and analyze the key factors that have a greater impact on it, this study collected 9 types of water environment physical and chemical parameters from 10 water quality monitoring sections from 2017 to 2019; the water environment characteristics of the water source area of the water diversion system from the Hanjiang River to the Weihe River were analyzed and evaluated by using the variance analysis method, the hierarchical cluster analysis method and the water quality identification index evaluation method. The results were as follows. (1) There was spatiotemporal heterogeneity in a number of physical and chemical parameters in the water body of the water source. In terms of time, the concentrations of COD, COD, BOD and F were higher in the flood season (July-October) than in the non-flood season (November-June). The concentrations of DO, TP and TN in the non-flood season were higher than those in the flood season. Spatially, the concentration of physical and chemical parameters of the water body in the Huangjinxia Reservoir area was higher than that in the Sanhekou Reservoir area. (2) The water quality of the water source area was good. The comprehensive water quality reached the Class II water quality standard of surface water environmental quality. Time showed that the comprehensive water quality in the non-flood season was better than that in the flood season. Spatially, the overall water quality of the tributaries was better than that of the mainstream. TN is a key indicator that affects water quality. (3) The spatial and temporal differences in water quality in water source areas are mainly affected by factors such as rainfall, temperature and human activities. This study can provide a scientific and data basis for related research on maintaining and improving the quality of the ecological environment of the water source areas of the Hanjiang to Weihe River Water Diversion System.
南水北调中线水源区水质时空变化特征及关键影响因素分析
南水北调中线工程水源地是中国重要的饮用水水源地之一，其水质关系到丹江口水库至郑州段长距离调水工程的用水安全。为了探究水源区水环境特征的时空变化趋势，并分析对其影响较大的关键因素，本研究于 2017 年至 2019 年在南水北调中线水源区共采集了 10 个水质监测断面的 9 类水环境理化参数，采用方差分析、层次聚类分析和水质标识指数评价法对南水北调中线水源区的水环境特征进行了分析和评价。结果表明：（1）水体中多项理化参数具有时空异质性。就时间而言，丰水期（7 月-10 月）各断面 COD、高锰酸盐指数、BOD5 和氟化物的浓度均高于枯水期（11 月-6 月），而 DO、TP 和 TN 的浓度则相反。就空间而言，黄荆峡水库区域水体理化参数的浓度高于三河口水库区域。（2）水源区水质整体良好，综合水质达到地表水环境质量Ⅱ类标准。时间上，枯水期的综合水质优于丰水期；空间上，支流的整体水质优于干流。TN 是影响水质的关键指标。（3）水源区水质时空差异主要受降雨、温度和人类活动等因素的影响。本研究可为丹江口水库至郑州段长距离调水工程水源区生态环境质量维护与改善的相关研究提供科学数据基础。
