基于SWAT模型的陕西沣河流域非点源污染模拟

Simulation on non-point source pollution based on SWAT model in Fenghe River watershed of Shaanxi Province

随着工业点源的大幅治理和农业的快速发展,陕西沣河流域非点源污染负荷在总负荷中所占比重日益加大。本文应用SWAT模型,对沣河流域的径流、泥沙及营养盐污染负荷的产输出过程进行模拟计算。利用沣河干流秦渡镇水文站2001-2006年的实测月径流、泥沙和污染物数据进行了模型的率定和验证。验证结果表明:模型在沣河流域具有较好的适应性,可用于流域非点源污染的模拟计算。流域非点源污染产出时空分布结果表明:非点源负荷产出集中在汛期;流域中部长安区的五星、滦镇、子午地区,以及流域西部户县的草堂镇和秦渡镇,是非点源污染产出的关键区域。流域非点源污染控制措施效果模拟表明:采取水土保持措施、改进化肥施用方式、合理减少施肥量可以有效减少流域非点源污染负荷。

With the increasing control strength of industrial point source pollution and instant development of agriculture,the proportion of non-point source pollution(NSP) loading occoupied total pollution loading in the Fenghe river watershed is rapidly rising.The SWAT model is applied to simulate the producing and transporting process of runoff,sediment and nitrogen non-point source pollution.The monthly obsereal runoff,sediment and pollutant data from 2001 to 2006 at the Qindu town hydrological station in the main stream of the Fenghe river were used to calibrate and verify the model.The results of verification show that the model has good adaptability in the watershed and is available.The NSP loading output analysis on spatial and temporal distribution show that the NSP loading output distributes in flood reason and the critical source areas of NSP loading output are the towns as Wuxing,Luanzhen and Ziwu of the Chang′an County in the middle of the watershed,and the towns as Caotang and Qinduzhen in Huxian County in the west of the watershed.The effect simulation of NSP control measures show that the measures such as soil and water conservation,improving application methods of chemical fertilizer,and reasonably reducing fertilizer volume can effectively decrease NSP loading in the watershed.