关键词: 评价指标, 影响因素, 测定与估算方法, 时空分异特征, 土壤可蚀性

Abstract: As the key elements of urban ecosystems, green land, woodland, and wetlands (three types of land) sustainably provide ecological services. Shanghai is promoting the construction of ecological city. It is necessary to evaluate urban ecological environment level involving green land, woodland and wetlands. According to the feature and the scale of construction of green land, woodland, and wetlands in Shanghai, ecological environment in Shanghai was statistically analyzed in order to establish an evaluation index system for the three elements. This article statistically analyzes Shanghai’s ecological environment, and therefore builds an evaluation index system for these three ecological elements. By the method Analytic Hierarchy Process (AHP), we clarify the index system into three categories, i.e., quantitative indicators with target, quantitative indicators without target and qualitative indicators, and give 5level rankings under each category. Based on this index system, we perform membership evaluation and thereafter render a result with comprehensive assessment. The result indicates that within the scope of single indicator,vetical greening, woodland structure and wetland consevation, as well as their mutual connectivity require improvement. The comprehensive assessment shows that the memberships of levels I, II, III, IV and V are  0.3261, 0.3411, 0.2208, 0.0707, and 0.0446. In conclusion, the overall status of the three types of land in Shanghai is at level II, a relatively high level in ecological environment costruction, yet it still has space to improve.

Key words: spatialtemporal variation characteristics, soil erodibility, evaluation indicator, measure and estimation method, influencing factor.