基于WQI的河网水系水质评价及时空特性分析

WQI Based Water Quality Assessment and Spatial-temporal Variation Analysis in River Network

为全面了解上海市主要河网水质的变化情况,基于2015~2020年主要河流上19个水质监测断面逐月水质监测数据,采用综合水质标识指数(WQI)进行水质评价,基于M-K趋势检验法分析研究区域水质的年代际和年内变化特征,通过比较南北部河流以及上、中、下游的水质变化,分析该地区主要河网水系水质的空间变化及时空差异特性。结果表明,上海市主要河网水系水质整体WQI均值为62.32,水质评价等级为中等;水质WQI值有显著上升趋势;南部河流水质优于北部河流,WQI值从上游向下游依次减小,水质沿程有所变差,但干流水质总体优于支流。研究结果可为类似河网水系的水质评价及水环境保护与管理提供参考。

In order to comprehensively understand the water quality changes of major river networks in Shanghai,a comprehensive water quality identification index(WQI)was used for water quality assessment based on the monthly water quality monitoring data of 19 water quality monitoring sections of the research area from 2015 to 2020.By using the M-K trend test method,the interannual and intra year changes in regional water quality were analyzed.By comparing the water quality changes of the northern and southern rivers,as well as the upstream,middle,and downstream areas of the main streams,the spatial changes and spatiotemporal differences in the water quality were analyzed.The results show that the overall average WQI of the water quality in the major river networks was 62.32,and the water quality evaluation level was"medium";The WQI value of water quality has significant upward trend;water quality of the southern rivers was better than that of the northern rivers.The WQI of the main stream decreased from upstream to downstream,meaning that the water quality got worse along the way.The water quality of the main stream had been better than that of the tributaries on the whole.The research results can provide certain references for water quality assessment,water environment protection and management to similar river network water systems.