基于SWAT模型的小流域面源污染负荷时空分异研究——以重庆市万州区陈家沟小流域为例

Spatial and Temporal Differentiation of Non-Point Source Pollution Load of a Small Watershed Based on SWAT Model

以三峡库区陈家沟小流域为研究区,通过实地监测调查和资料收集建立空间和属性数据库,采用2006、2007年监测数据建立SWAT模型,并进行模型参数率定,利用2008、2009年的监测数据进行模型验证。应用验证后的SWAT模型模拟分析研究区面源污染负荷的时空分异规律以及不同土地利用类型污染负荷的差异性,结果表明:空间上,小流域内不同子流域的污染负荷存在差异;时间上,污染负荷分布与降雨周期、农药化肥施用时间密切相关;不同土地利用类型面源污染负荷存在差异,耕地负荷最大,林地最小。针对面源污染负荷的时空分异性,综合考虑土地利用方式和小流域生态、经济要求,提出了小流域面源污染防治措施配置建议。

It established spatial and attribute database through field monitoring and investigation and data collection by taking Chenjiagou Small Watershed in the Three Gorges Reservoir Area as studied region,built SWAT model and calibrated parameters by using monitoring data of 2006 and 2007 and validated the model by using monitoring data of 2008 and 2009. It applied the validated model to simulate and analyze the temporal and spatial law of differentiation of non-point source pollution load and the difference of pollution load of different land use types of the studied area. The outcomes show that a) there is difference on pollution load for different sub-watersheds in the small watershed on spatial aspect; b) on temporal aspect,the distribution of pollution load is closely related with the period of rainfall and the time of pesticide and fertilizer application and c) there is difference in non-point source pollution load for different land use types. The load of cultivated land is the maximum and forest land the minimum. It puts forward suggestions on prevention and control measures for small watershed non-point source pollution in the light of temporal and spatial differentiation of the pollution load and the comprehensive consideration of the types of land use and the ecological and economic requirements of the small watershed.