怀柔水库上游农业氮磷污染负荷变化

Pollution loads variation of agricultural source in upstream of Huairou Reservoir

流域尺度农业污染负荷估算及其时间上的变化分析可为流域农业结构调整以及水污染控制和治理提供科学依据。利用输出系数模型,对怀柔水库上游两怀流域2000年和2011年的农业污染负荷总氮和总磷进行了估算和变化分析,揭示了各类农业活动对两怀流域氮磷污染的影响。结果表明:从2000到2011年两怀流域农业氮和磷负荷总量有增加的趋势,分别从2000年的454.029和51.014 t上升到2011年的485.961和58.437 t,其中水产养殖氮、磷负荷量增加比重最大。流域内农业土地利用及产业结构变化是引起氮磷污染负荷发生变化的主要原因。建议针对不同污染源类型,采取相应减控措施减少各类污染物排放量;同时,大力发展流域循环经济模式,实现种植业、养殖业和农村生活废弃物的资源化和再生利用。

Increased nutrient （i.e., nitrogen and phosphorus） concentrations have been observed in the surface water bodies inmany counties. Agricultural non-point source （NPS） pollution has been identified as one of the most important factors in causing water quality deterioration. To control NPS pollution effectively, it is necessary to quantifying agricultural pollution loads and understanding contribution of the pollution sources. Furthermore, watershed-based analysis can provide scientific basis for agricultural practices and water pollution control. In this paper, the general export coefficient model was used to estimate the loads of total nitrogen （TN） and total phosphorus （TP） from the upper Lianghuai basin of Huairou Reservoir for year 2000 and 2011. The model results showed that the total nitrogen and total phosphorus loads in 2000 were mainly contributed from the farmland planting, livestock and poultry breeding., while aquatic agriculture mainly contributed the total nitrogen and total phosphorus loads in 2011. Agricultural nitrogen and phosphorus loads increased in the study area during two year period. The nitrogen load increased from 454.029 ton in 2000 to 485.961 ton in 2011, while phosphorus load increased from 51.014 ton in 2000 to 58.437 ton in 2011. The nitrogen and phosphorus loads from aquatic agriculture took account of the largest percentage among the agricultural pollution sources. The agricultural land use and industrial structure changes caused nitrogen and phosphorus loads changed from 2000 to 2011 in the study basin. In the future, the corresponding control measures are recommended according to different pollution sources in order to reducing their pollution discharges. Moreover, recycling economy pattern is encouraged to achieve the resource utilization and reuse of planting, breeding and rural life waste.