黄土丘陵区小流域生态经济系统健康评价

建立健康的流域生态系统是恢复退化的生态系统、实现黄土高原山川秀美的目标。论文以安塞纸坊沟小流域为对象,利用层次分析法,选取林草覆盖度、基本农田面积、土壤抗冲性、土壤有机质含量、农业产投比、粮食单产、人均纯收入和综合治理减沙效率等反映流域生态经济系统功能评价指标,定量分析了黄土丘陵区安塞纸坊沟小流域进行水土保持型生态农业的建设中生态系统恢复的过程。研究表明,该小流域经过近20年治理,经历了起始恢复、稳定发展阶段,开始进入良性循环。其健康指数由1985年的0.178增加到1999年的0.707。研究中首次引入土壤抗冲性和有机质指标,并在评价中对生态系统恢复不同阶段给予各指标不同权重值,对方法进行了改进。

An analysis on eco-economy system health in Zhifanggou Small Watershed of Ansai on Loess Hilly-Gullied Region

The aim of establishing a healthy ecosystem is to rehabilitate the degenerated ecosys-tem and turn the landscapes of the Loess Plateau green.The Chinese Government has promoted integrated watershed management measures for years to control soil erosion and improve the eco-environmental conditions in a hilly-gullied region of the Loess Plateau.However,there is still no proper method for assessing the health of the ecosystem.This paper,taking Zhifanggou Water-shed in Ansai County as an example,by using the hierarchical approach and selecting evalua-tion indicators such as forest and grass coverage,area of fundamental cropland,soil anti-scoura-bility,soil organic matter content,output/input ratio,per unit area crop yield,per capita net in-comes and benefit of soil erosion control by comprehensive management,the improvement pro-cess in ecosystem rehabilitation of the watershed was analyzed.The result showed that after about 20years of soil conservation practice,the ecosystem health index of the watershed has im-proved from0.178in1985to0.707in1999after experiencing initial restoration,stable im-provement and benign circulation period.This research introduced for the first time the new in-dicators of soil anti-scourability,soil organic matter content and gave the different weight value of indicators in health index calculation in the rehabilitation process.