江苏省里下河腹部区水质时空变化特征分析

Analysis on temporal and spatial variation characteristics of water quality in Lixiahe abdominal area,Jiangsu Province

基于里下河腹部区2010~2018年46条河流86个断面的逐月水质监测数据,运用单因子评价方法和GIS空间分析方法,分析里下河腹部区水质时空变化特征,为里下河腹部区水环境治理与保护提供依据。里下河腹部区水质时间变化特征为:非汛期(1~4月、10~12月)水质优于汛期(5~9月),12月水质最佳,7月水质最差;近年来高锰酸盐指数和氨氮浓度总体均呈较为明显的下降趋势。水质空间变化分析表明:非汛期水质总体较好,中部的泰州兴化、扬州高邮段水质较差;汛期水质总体较差,仅部分流域性或区域性骨干河道水质达标,西南部、东北部和中部地区水质最差。区域水质时空变化特征与外引水源水量关系密切,外引水源对改善区域水质的影响逐渐增大。

Based on the monthly water quality data of 86 monitoring sections of 46 rivers in Lixiahe abdominal area from 2010 to 2018,this paper analyzes the spatial and temporal variation characteristics of water quality by using single factor evaluation method and GIS spatial analysis method.Analysis on temporal variation of water quality shows that the water quality in the flood season(May^September)is worse than that in the non-flood season(January^April,October^December).The worst water quality period is in July,while the best one is in December.In recent years,the permanganate index and ammonia nitrogen concentration have shown an obvious downward trend.Spatial variation analysis of water quality shows that the water quality in non-flood season is generally good,but it is poor in Xinghua City and Gaoyou City sections in the central part.Water quality in flood season is generally poor,only some of the main watershed or regional river channels meet water quality standards,and water quality in the southwest,northeast and central areas are the worst.The temporal and spatial variation of regional water quality is closely related to the volume of externally introduced water.Effects of external introduced water on improving regional water quality are increasing.