The model has overlay and index method as the basic , mathematical model and statistical method embedded to form an integrated model . the hydrus model is performed to obtain the rating system , and principal component analysis and factor analysis are used to get the weighting system 该模型以参数系统法为基础,将数学模型和统计方法嵌入该综合模型中,通过hydrus模型进行数值模拟来建立评价因子的评分体系,权重体系由主成分因子分析法得到。