利用黄河中游干旱半干旱区三川河流域20世纪80年代的降雨径流资料,构建了三川河流域的分布式水文模型SWAT(Soil and Water Assessment Tool),并对三川河流域的月平均流量过程进行了模拟,分析了月径流量的变化特征。模拟结果表明,月平均流量较实测的结果偏大,模型率定期和验证期的Nash-Sutticliffe效率系数分别为0.711和0.725。虽然Nash-Sutticliffe效率系数基本符合精度要求,但是模型中一些参数已经达到模型设置的临界值,进一步分析得出,由于流域上雨量站的数据不够,以及中国与美国土壤、土地利用数据库编码的差异,使得模型模拟结果受到影响,并且三川河流域自70年代以来水土保持措施蓄水效益较为显著,在一定程度上使得径流量减少,使得模拟结果偏大。
Urban green land compensation plays an impor-tant role in county development,ecological environment management and many other fields.The concept,methods and principles of urban green land are introduced in this paper.According to the pay fee method,the value and ecological function of various types of urban green land were analyzed.The cost-benefit analysis method(CBAM)was used to estimate different external diseconomy benefits caused by green land loss.The authors applied CBAM to estimate such benefits in the case of Shanghai,China,and calculated the actual compensation value for green land.Results indicated that in 2002,the compensation value for the green land of Shanghai was RMB 8.58×10^(5) Yuan/hm^(2).
