赣江下游不同样地降雨径流氮磷污染负荷估算

Nitrogen and phosphorus pollution loads from the different land use types in the Ganjiang River downstream

选择赣江下游地区不同样地类型的径流小区,遇到大降雨时监测径流水样中的氮、磷含量,并利用SCS模型计算降雨径流量,从而估算不同样地类型降雨径流中氮、磷的污染负荷。结果表明,不同土地利用类型中氮、磷的输出量差异显著,其氮、磷的污染负荷均以水田最高,分别达到10732.91 t·a^(–1)与1071.65 t·a^(–1),而以林地最小,分别为657.53 t·a^(–1)与166.70 t·a^(–1),反映了降雨径流下水田的溶解态氮、磷流失量最大。因此,水田的氮、磷流失是赣江下游需要重点考虑的因素。

Several runoff units of various land use areas are selected to monitor nitrogen and phosphorus contents in Ganjiang River downstream. Using SCS runoff curve, runoff of each plot is calculated. Considering the actual concentration of nutrient, loading of nutrient of surface runoff is estimated. The results show that phosphorus and nitrogen outputs in runoff were significant in different land use patterns, and high nitrogen and phosphorus loads are associated with paddy land use, which are 10732.91 t·a^（–1） and 1071.65 t·a^（–1）, respectively. The amount of nutrient loss from woodland is the lowest, which are 657.53 t·a^（–1） and 166.70 t·a^（–1）. Being carrier of loss nutrients, the paddy land use is thought to be the controlling focus in Ganjiang River downstream.