基于GIS和模型的流域非点源污染控制区划

采用GIS技术和USLE,SCS-CN,污染物流失经验模型及AnnAGNPS机理模型相结合,对农业集约化程度较高的南方中等尺度流域进行农业非点源污染控制区划.结果表明:利用GIS和经验模型回答了流域农业非点源污染氮磷来源与贡献,标识了农业非点源污染氮磷等污染物的关键源区,发挥了经验模型所需模型参数少、研究尺度较大、效率较高的优点,通过GIS的栅格数据空间分析功能,实现了流域非点源污染的分布式模拟,识别了NPS的关键源区.借助AnnAGNPS机理模型,在模型得以校验的前提下,模拟了非点源污染管理措施方案.以模型和GIS的定量结果为依据,对九龙江流域农业非点源污染控制进行了区划,共划分了水土流失控制区、生猪养殖+水土流失控制区、化肥施用+生猪养殖控制区、水土流失+化肥施用控制区及化肥施用+水土流失控制区5类控制单元. 

Control Divisions of Agricultural Non-point Source Pollution at Watershed Scale Based on GIS and Models

GIS technology and USLE,SCS-CN,nutrient losses empirical equations and AnnAGNPS model were coupled to carry on control divisions of NPS in a mediumsized watershed,located in southeast of China,with relative strong intensive agricultural activities.The results show that the integration of GIS with empirical models can help analyze major sources and contributors of NPS,and identify the critical source areas of NPS.This can not only develop the advantages of empirical equations,e.g.requiring less model parameters,having large scale under study and being more efficient,but also realize simulation of watershed non-point source pollution and identify critical source areas of NPS through spatial analysis functions,increasing visual display effect of the results.After calibrating and validating the AnnAGNPS model,several scenarios were designed and simulated for suggestions of best management practices(BMPs).Finally,based on the quantitative results derived from GIS and the models,five control division units were generated for non-point source pollution control in Jiulongjiang River watershed,namely,soil losses controlling unit,livestock breeding & soil losses controlling unit,fertilizer use & livestock breeding controlling unit,soil losses & fertilizer use controlling unit and fertilizer use & soil losses controlling unit.