An analysis on eco-economy system health in Zhifanggou Small Watershed of Ansai on Loess Hilly-Gullied Region
黄土丘陵区小流域生态经济系统健康评价

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.