基于“3S”技术的大伙房水库汇水区农村生活污染负荷分析

Analysis on Pollution Load of Rural Life in Dahuofang Reservoir Watershed based on 3S Technology

运用ArcGIS软件解译大伙房水库汇水区的卫星影像数据,结合行政区划图确定汇水区3条主要河流两岸1000m为农村生活污染负荷评估范围,采用排污系数法估算农村生活污染负荷。结果表明,研究区农村生活污染负荷为8420.28t/a,其中,生活污水的污染负荷占总量的99.40%。农村生活污染对流域水质的贡献率为27.84%,所排放的污染物对河流的贡献率大小依次是氨氮(34.95%)、总磷(27.81%)、化学需氧量(25.53%)和总氮(23.08%),农村生活污染已成为大伙房水库汇水区水体污染的重要源。

Non-point source pollution is characterized by randomness,uncertainty,latency and lag.There are various pollutants with large emissions.When these pollutants come into receiving water bodies,they are complex in the migration and transformation.Dahuofang Reservoir is located in Liaoning province,which is one of the important drinking water sources in Liaoning province.Dahuofang Reservoir catchments include Hun River,Suzi River and She River.With the rapid development of small townséconomy and agriculture,non-point source pollution of rural life is more and more serious.In order to provide decision support for Dahuofang Reservoir catchment＇s water pollution research and control,3S technology and discharge coefficient method was combined to estimated pollution load of rural life.In the paper,ArcGIS was used to interpret the satellite images of Dahuofang Reservoir catchments.The scope of the assessment for the pollution load of rural life was set at 1 000 m from the rivers.Discharge coefficient was adopted to estimate pollution load of rural life.Discharge coefficient was an effective and widely used method to estimate the pollution load of domestic pollution source.Compared with other methods,it less dependent on water quality monitoring data and its required data was easier to be obtained.As the study area of this paper was rural area,this method could compensate for the shortcoming of lack of monitoring data.The results of research showed that the pollution load of rural life in the assessment scope was 8 420.28 t/a,and the pollution load of sewage accounted for 99.40%.Sewage was the main source of rural life pollution caused by non-point source pollution.Pollution load of the rural life in Hun River was the largest,followed by Suzi River and She River.The contribution rate of rural life on the watershed water quality was 27.84%,the contribution rate of pollutants on the watershed are ammonia nitrogen（34.95%）、total phosphorus（27.81%）、chemical oxygen demand（25.53%） and ammonia nitrogen（23.08%）.The main factor affecting Hun River,Suzi River and She River is ammonia nitrogen,followed by total phosphorus.Pollution caused by rural life had become an important source of water pollution.According to the characteristics of the topographical features and emission of pollutants,we proposed a number of specific recommendations.