宁南山区退耕还林还草效益评估研究

Assessing benefits of the conversion of cropland to forest and grassland project in the mountain area of southern Ningxia

从生态发展与区域自然、社会、经济复合协调的系统角度出发,建立分层评价指标体系,借鉴相关专家的研究成果推算直接测量比较困难的部分数据,并在总结目前生态效益评价定量方法的基础上,利用主成分分析法计算了近5年来宁南山区退耕还林还草产生的效益。结果表明,宁南山区退耕还林还草工程2004年发挥的效益是2000年的近2.2倍,各年的平均增长率都达到50%左右,生态效益逐步发挥,从时间序列上呈积累式增加趋势。

The paper sets up the index systems from the theory of social, economic and ecological complex system, and calculates the segmental data which are difficult to measure using relevant experts＇ research results for reference. Based on the method of quantitatively describing the ecological benefit, the paper uses the principal component analysis （PCA） to calculate the project of the Converting Slope Farmland into Forestland and Grassland during the last five years. The result shows that the ecological benefit of the project of Converting Slope Farmland into Forestland and Grassland in mountain area of southern Ningxia in 2004 is 2.2 times to 2002. The increase has average out at 50 % every year. The cal benefit is shown gradually and accumulating