Simulation of spatial and temporal distribution on dissolved non-point source nitrogen and phosphorus load in Jialing River Watershed, China
Simulation of spatial and temporal distribution on dissolved non-point source nitrogen and phosphorus load in Jialing River Watershed, China
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DOI：
10.1007/s12665-011-1159-9
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发表时间：
2012-01
影响因子：
2.8
通讯作者：
Lei Wu;Tian-yu Long;W. Cooper
中科院分区：
文献类型：
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作者：
Lei Wu;Tian-yu Long;W. Cooper
嘉陵江流域面积16万平方公里，全长1280公里，是中国三峡库区集水区最大的支流。近年来，嘉陵江库区段由于土地利用和农村居民点污染等原因，水质不断恶化。为此，引入半分布式土地利用径流过程（SLURP）水文模型，对嘉陵江流域进行综合水文循环模拟。提出了SLURP水文模型与溶解非点源污染模型之间的耦合流域模型，以评估潜在的溶解非点源污染负荷；在流域土地利用类型划分相同的前提下，提高了径流和污染负荷的模拟精度。利用该模型模拟了1990-2007年江淮流域溶解总氮（DTN）和溶解总磷（DTP）污染负荷的时空分布。结果表明，DTN和DTP负荷的时空分布均与年降雨量高度呈正相关。土地利用是控制DTN和DTP负荷分布的关键因素。DTN和DTP来源组成不同，DTN平均污染负荷由大到小依次为土地利用67.2%、畜禽养殖30.5%、农村聚落2.2%；畜禽养殖占50%，土地利用占48.8%，农村居民点占1.2%。各子流域DTN和DTP负荷的贡献率反映了结果对不同污染源时空分布的敏感性。这些数据对于预测和估计长江流域降雨径流携带的溶解非点源污染负荷的未来变化趋势以及研究其在三峡库区的迁移和影响具有重要意义。
Jialing River, which covers a basin area of 160,000 km2and a length of 1,280 km, is the largest tributary of the catchment area in Three Gorges Reservoir Area, China. In recent years, water quality in the reservoir area section of Jialing River has been degraded due to land use and the rural residential area induced by non-point source pollution. Therefore, the semi-distributed land-use runoff process (SLURP) hydrological model has been introduced and used to simulate the integrated hydrological cycle of the Jialing River Watershed (JRW). A coupling watershed model between the SLURP hydrological model and dissolved non-point source pollution model has been proposed in an attempt to evaluate the potential dissolved non-point source pollution load; it enhances the simulation precision of runoff and pollution load which are both based on the same division of land use types in the watershed. The proposed model has been applied in JRW to simulate the temporal and spatial distribution of the dissolved total nitrogen (DTN) and dissolved total phosphorus (DTP) pollution load for the period 1990–2007. It is shown that both the temporal and spatial distribution of DTN and DTP load are positively correlated to annual rainfall height. Land use is the key factor controlling the distribution of DTN and DTP load. The source compositions of DTN and DTP are different, where average DTN pollution load in descending order is land use 67.2%, livestock and poultry breeding 30.5%, and rural settlements 2.2%; and for DTP, livestock and poultry breeding is 50%, land use 48.8%, and rural settlements 1.2%. The contribution rates of DTN and DTP load in each sub-basin indicate the sensitivity of the results to the temporal and spatial distribution of different pollution sources. These data were of great significance for the prediction and estimation of the future changing trends of dissolved non-point source pollution load carried by rainfall runoff in the JRW and for studies of their transport and influence in the Three Gorges Reservoir.