摘要:To interpret water quality responses to pollution loads and quantify the concentrations of pollut⁃ants in rivers,a method of water quality simulation model (WASP) integrated with geographical information system (GIS) was presented and a case study was conducted in the catchment basin of the Jiaokou Reser⁃voir in Ningbo, China. The hydrologic model in AcrGIS and a digital elevation model(DEM) with a spatial resolution of five meters were applied to generate the river hydrological networks and the ranges of basins and watersheds, then the river networks of the of the study area were divided into 168 simulation units. The spatial and hydrological characteristics data of the simulation units from GIS, along with the data of pollutants loads, flows, river hydrologic parameters, water quality parameters and boundary conditions, were converted and integrated to WASP. The spatial distributions of water quality variables in Jiaokou Reser⁃voir Basin were simulated, and the computational segment data and water quality output data from WASP were combined with GIS geodatabase to visualize and statistically analyze the results. The simulation results show that the calculated values of chemical oxygen demand, ammonia nitrogen, total nitrogen and total phosphorus agree well with the measured values from 6 sampling stations, with the average relative devia⁃tions of 10.4 %, 18.7 %, 17.4 % and 19.9 % respectively. The average relative deviations of the four vari⁃ables between the daily simulated values and measured values from the sampling station ahead of reservoir gate are 7.5 %, 13.3 %, 8.6 % and 18.6 %, respectively. The GIS-based water quality simulation method can be applied to study the spatial and temporal distribution of water quality in Jiaokou Reservoir catch⁃ment basin, and the case study confirms the applicability and efficiency of GIS-based water quality simula⁃tion in water quality management decisions.%为探讨基于地理信息系统(GIS)的流域水质模拟方法,以宁波市皎口水库流域为例,应用ArcGIS的水文分析模块和空间分辨率为5 m的数字高程模型(DEM)生成研究区流域水系及各级汇水边界,并将流域水系划分为168个水质模拟单元。根据调查统计及实验方法获得流域污染负荷、径流量、河道水力参数、水质参数和边界浓度,并建立相应的地理信息数据库及水文水环境属性数据库。通过集成水质模型(WASP)与 GIS的空间分析功能,对流域水质时空变化特征进行模拟,并利用ArcGIS实现水质模拟结果的可视化表达和统计分析。结果显示:6个监测点的高锰酸盐指数、氨氮、总氮及总磷的模拟浓度与实测值的平均相对偏差分别为10.4%、18.7%、17.4%和19.9%,水库闸前监测点高锰酸盐指数逐日模拟值与实测值的平均相对偏差为7.5%,氨氮为13.3%,总氮为8.6%,总磷为18.6%,模拟浓度与实际监测值的总体趋势相符。研究表明,基于GIS的水质模拟方法能够应用于流域尺度水质时空分布规律的研究,利用GIS对模拟结果进行空间表达及统计分析为皎口水库流域水环境保护与污染控制决策提供了科学依据。