基于L-THIA模型的市桥河流域非点源氮磷负荷分析  

Analysis on Nitrogen and Phosphorus Loading of Non-point Sources in Shiqiao River Watershed Based on L-THIA Model

作　　者：李凯[1,2] 曾凡棠[1] 房怀阳[1] 林澍[1] 

机构地区：[1]环境保护部华南环境科学研究所,广州510655 [2]中国环境科学研究院,北京100012

出　　处：《环境科学》2013年第11期4218-4225,共8页Environmental Science

基　　金：国家水体污染控制与治理科技重大专项(2008ZX07011-0010)

摘　　要：以番禺市桥河流域为研究对象，利用现场建立的不同土地利用类型的径流场实测降雨径流数据，对长期水文影响评价模型（L-THIA）的主要参数进行校正，模拟计算该流域非点源氮磷负荷量，并分析土地利用和降雨变化对氮磷负荷输出的影响．结果表明，市桥河流域内非点源氮磷污染高负荷区主要集中在农业用地和城镇用地，单位面积污染负荷输出最高的为农业用地．从1995-2010年，流域非点源氮磷负荷呈增加趋势，TN增加了17．91％，而TP的增加幅度达到了25．30％．随着流域城镇化的迅速发展，城镇用地明显增加，所占比例达到了43．94％，2010年对负荷总量的贡献率也已超过40％，几乎与农业用地持平，这也是近15年来流域内农业用地面积虽然有所降低，但污染负荷总量仍然增加的主要因素．流域内降雨主要集中在汛期，因而汛期非点源氮磷负荷亦远高于非汛期，占全年比例超过了85％．不同降雨类型发生次数与污染负荷的Pearson相关分析表明，日降雨量大于20mm的降雨是造成流域内非点源氮磷污染的主要降雨类型．Based on the Long-term Hydrological Impact Assessment （L-THIA） model, the effect of land use and rainfall change on nitrogen and phosphorus loading of non-point sources in Shiqiao river watershed was analyzed. The parameters in L-THIA model were revised according to the data recorded in the scene of runoff plots, which were set up in the watershed. The results showed that the distribution of areas with high pollution load was mainly concentrated in agricultural land and urban land. Agricultural land was the biggest contributor to nitrogen and phosphorus load. From 1995 to 2010, the load of major pollutants, namely TN and TP, showed an obviously increasing trend with increase rates of 17.91% and 25.30% , respectively. With the urbanization in the watershed, urban land increased rapidly and its area proportion reached 43.94%. The contribution of urban land to nitrogen and phosphorus load was over 40% in 2010. This was the main reason why pollution load still increased obviously while the agricultural land decreased greatly in the past 15 years. The rainfall occurred in the watershed was mainly concentrated in the flood season, so the nitrogen and phosphorus load of the flood season was far higher than that of the non-flood season and the proportion accounting for the whole year was over 85%. Pearson regression analysis between pollution load and the frequency of different patterns of rainfall demonstrated that rainfall exceeding 20 mm in a day was the main rainfall type causing non-point source pollution.

关 键 词：非点源 氮磷 L-THIA模型 土地利用 降雨 

分 类 号：X52[环境科学与工程—环境工程]