基于SLURP模型和输出系数法的三峡库区非点源氮磷负荷预测

Forecasting the pollution load of non-point sources imported to the Three Gorges Reservoir

为研究三峡入库非点源污染的变化规律,以输出系数法为基础,引入污染负荷系数,建立了计算三峡库区上游流域非点源氮磷负荷的数学模型.将所建立的非点源负荷模型与分布式SLURP水文模型相结合,借助地理信息系统和遥感技术,对该流域土地利用/土地覆盖和气候特征下的流域水文动态过程,以及水文动态过程下该流域输入三峡库区的非点源氮磷污染负荷进行了相关预测和分析.预测结果显示:2020年由于该流域土地利用的变化,非点源氮磷污染的产生量略有减少,但地表径流量的增加使输入库区的非点源氮磷污染负荷有所增加;未来农田产生的污染物量有所减少,但农田仍然是形成氮磷负荷的最主要来源.

A mathematical model of non-point source pollution loading has been established to study the change laws of non-point source pollution imported to the Three Gorges Reservoir. This model was obtained by the Export Coefficient Approach and by introducing a pollution load coefficient. Using GIS and RS technology, the SLURP hydrological model and a model of pollution loading of non-point sources are applied to forecast and analyze the change of nitrogen and phosphorus pollutant loads imported to the Three Gorges Reservoir considering changes of land use and climate. The predictions show that in 2020, although production of non-polnt source nitrogen and phosphorus of watershed will decrease as the land uses change, their loads will increase due to climate change. The research results also indicate that pollutant production from cropland will be reduced, but it will remain the most important source of nitrogen and phosphorus export in the watershed.