基于SWAT模型的三峡库区流域污染物来源分析及重点控制区域识别

随着非点源污染逐步成为三峡库区流域污染的重要控制对象,将SWAT模型应用于三峡库区流域非点源模拟研究,以识别库区非点源污染来源关键区域.模型建立后采用2002—2008年水文、水质实测数据进行率定与验证,径流、泥沙、营养盐的评价指标ENS均达到令人满意的效果,表明SWAT模型应用于三峡库区流域是可行的.通过对三峡水库污染物的来源分析可知:三峡库区上游汇入为库区污染物的主要来源,贡献率平均为71.74%,库区流域非点源污染贡献率最高为33.03%,而库区点源污染贡献率较小,最高仅为4.17%.对库区单位面积污染负荷的模拟研究表明:三峡库区流域非点源污染物产生的关键区域主要集中在库区腹部,即小江、大宁河、汤溪河等支流流域.

Pollutant Source Analysis and Identification of Prior Control Areas in Three Gorges Reservoir Based on SWAT Model

SWAT model was applied to Three Gorges Reservoir(TGR) region to study the non-point source pollution and identify the key areas of pollution in this research.After the model was established,observed data of hydrological and water quality from 2002 to 2008 were used for the simulation calibration and validation.The simulation for the indicator ENS(Nash-Suttclife efficiency) of stream flow,sediment,nutrient were satisfying.Pollution source of TGR was studied later.The result showed that upstream input was dominant with 71.71% average contribution rate,non-point source pollution of TGR watershed came second with the maximal contribution rate 33.03%,and point source of TGR watershed was the lowest which accounted for 4.17% at most.Finally,pollution loads per area of TGR were modified.According to the modification,main areas of non-point source pollution were located in the central of TGR watershed mainly,such as the tributary watershed of Xiaojiang River,Tangxi Rive and Daning River.