洛河流域非点源污染负荷不确定性的影响因素

 以黄河流域下游的洛河流域为研究区,利用1998年实测径流量、泥沙负荷和非点源污染资料,对非点源污染模型中的水文模型、土壤侵蚀模型与污染负荷模型进行了参数率定.并以此为基础,针对非点源污染负荷计算的影响因素,采用摩尔斯分类筛选法,分析它们对径流量、泥沙负荷、吸附态氮和溶解态氮模拟计算的敏感性.结果表明,在湿润、半湿润地区对径流量、泥沙负荷、吸附态氮和溶解态氮影3个因子分别是土壤可利用水量、土壤蒸发补偿量、SCS曲线系数.其中,土壤可利用水量产生负效应影响.坡度、坡长和作物管理因子对泥沙负荷和吸附态氮影响也比较显著.吸附态氮与泥沙负荷影响因子一致,说明吸附态氮污染主要与泥沙流失有关.

Uncertain affecting factor of the non-point source pollution load

With Luo River basin of Yellow River lower reach basin as study area, the data of runoff, silt load and non-point source pollution (N-pollution) actually measured in the year 1998 were applied for parameter rate determination of hydrographic model, soil erosion model and pollution load model in the N-pollution model and based on this, their sensitivity of simulated calculation of runoff, silt load, adsorbent nitrogen and dissolvent nitrogen was analyzed adopting Morris qualitative screening technique. Three most affective factors of the runoff, slit load, adsorbent and dissolvent nitrogens in the wet and semiwet areas were the available water amount in soil, the compensation amount for soil evaporation and SCS curve coefficient, in which the available water amount produced relative effect influence; next, the influence of the degree and length of slope also the crop managing factor on the silt load adsorbent nitrogen was obvious relatively. The adsorbent nitrogen agreed with the silt load affecting factor, explaining that the adsorbent nitrogen pollution was related mainly to the loss of silt.