Analysis of Land-Use Changes in Loess Hilly Region Based on PSR Model: A Case Study in Shanghuang Study Area in GuYuan City

The Pressure-State-Response model (PSR) proposed by the OECD and UNEP in 1994 was used to evaluate ecosystem health, In this paper, the PSR concept model was cited to reflect the pressures upon land resource in different time exerted by human activities, the responses of society to these pressures, and the state changes of land resources in different phase. A workable indicators system of PSR model is designed according to the characters of land resource in Loess hilly region. According to these indicators, we analyzed the land use and land cover change of the study area form 1982 to 2005 year. The results show that different responses measures to the pressures present different results during the process of land use. Before 1982 year, the inappropriate land use patterns in response to the pressures of population growth and socio-economic development leaded to eco-environmental degradation and poverty, while from "the Sixth Five-Year Plan" to "the Tenth Five-Year Plan", the rational measures of responses promoted the regional sustainable development, the net annual income per farmer increased from 47.7 Yuan(RMB) to 2093.2 Yuan(RMB), while the soil loss intensive decreased form 6000 t·km^-2·yr^-1 to 1000 t·km^-2·yr^-1.