Ecological and Environmental Assessment on the Effects of Water and Soil Loss Comprehensive Harness in Meso-scale Watershed in Loess Hilly Region

Abstract:

An index system was constructed for accessing eco-environmental effect of water and soil loss comprehensive harness in meso-scale based on the DPSIR model. The eco-environmental effect of grain for green project was accessed. The results showed that comprehensive value of environmental effect of ecological restoration increased by 30% in test stage, 43% in formal implement stage, 56% in restoration stage, respectively compared with those in the initial stage of evaluation; whereas the values of environmental subentry decreased by 6%, 20% and 22%, respectively; values of social subentry increased by 43%, 114% and 143%, respectively; the values of economic subentry increased by 29%, 129% and 129%, respectively. Grain for green, farmland pressure, sediment transport modulus and erosive precipitation were sensitive indices which indicated that there was a hysteretic nature of eco-environmental changes compared with driving and pressure factors. Impacts of the project of grain for green for eco-environment to response usually need a period of time.