黄土丘陵区榆林南部退耕还林(草)工程综合效益评价

Comprehensive Benefit Evaluation on Grain for Green Project in Loess Hilly Region of Southern Yulin

以地处黄土丘陵区的陕西榆林南部6县(米脂、绥德、佳县、吴堡、清涧和子洲)为例,对自1999年退耕还林(草)工程实施10年以来的综合效益进行评价。结果表明:榆林南部6县的固土保肥、固碳制氧和涵养水源效益是工程实施取得的主体生态效益,占总效益的99%;榆林南部6县工程实施对农业产业结构调整的贡献程度分别为50.5%、93.0%、4.2%、47.0%、5.0%和36.0%,对农村剩余劳动力转移的影响程度分别为1.1、2.1、1.1、2.0、0.3、3.2人/hm2,农户对工程实施均持基本满意态度。构建了由固土保肥、固碳制氧、涵养水源、工程实施对农业产业结构调整的贡献程度、工程实施对剩余劳动力转移的影响程度、第一产业占县域GDP比例、农户对工程实施的满意度和耕地压力指数8个指标组成的综合效益评价指标体系,建立了基于灰色关联度的退耕还林(草)工程综合效益评价模型,综合效益为子洲>米脂>吴堡>清涧>绥德>佳县。

Taking six counties, Mizhi, Suide, Jiaxian, Wubao, Qingjian, and Zizhou County, located in southern Yulin of Shaanxi Province in Loess hilly region as a case, the comprehensive benefit has been evaluated since the grain for green project was implemented for 10 years from 1999. The results showed that the benefits of preventing soil erosion and keeping fertility, carbon fixing oxygen replacement, and water conservation covered 99% with the total ecological benefit of these projects implementation. The contribution coefficients of project implementation on agricultural structure adjustment were 505%, 930%, 42%, 470%, 50% and 360%, respectively. The influence degree of project implementation on transferring surplus agricultural labor force were 11 persons/hm2, 21 persons/hm2, 11 persons/hm2, 2 persons/hm2, 03 person/hm2 and 32 persons/hm2, respectively. Basically, farmers were satisfied with the implementation of grain for green project. In conclusion, the project not only constructed a comprehensive evaluation system with eight indexes, including preventing soil erosion and keeping fertility, carbon fixing oxygen replacement, water conservation, the contribution coefficients of project implementation on agricultural structure adjustment, the influence degree of project implementation on transferring surplus agricultural labor force, the proportion of primary industry account for county area, the farmers satisfaction, and index of cultivated land pressure, but established the evaluation model of comprehensive benefits from grain for green project using Grey Correlation Degree Analysis method as well. The comprehensive benefits decreases followed the order： Zizhou 〉 Mizhi 〉 Wubu 〉 Qingjian 〉 Suide 〉 Jiaxian.