Evaluation Of Ecological Benefits Of The Different Measures On Serious Erosion Region Of Granite Area

Soil erosion is a worldwide environmental problem. In southern granite region, soil erosion is serious, it has become a most serious soil erosion area after Loess Plateau region. It had carried out a series of ecological restoration practice in this area, but the systematic evaluation of ecological benefits of various management measures was lack. Ecological benefits of four measures (Orchard rebuilding, Orchard planting, Eco Grass, old-man mason pine rehabilitation), launched in Changting County from 2000 to 2005 were evalued. The results showed that soil erosion reduced after restoration, runoff coefficient and soil erosion modulus decreased significantly; Vegetation coverage had been increased from about 20% to 60-80%. Soil physical and chemical properties were improved significantly after restoration. Based on the ecological conditions of Changting county and the data, we collected, a set of index system for ecological evaluation was established. This index system was composed of vegetation recovery, runoff coefficient, soil erosion modulus and Soil Quality Indicator. The weights of these indexes were 0.1854, 0.1186, 0.2510, 0.4450 respectively, using the objective and subjective assignment-Coefficient of variation method and the Analytic Hierarchy Process. And then the ecological benefits were evaluated by the Multi-level fuzzy comprehensive evaluation model.The evaluation of ecological benefits showed that Orchard rebuilding>Orchard planting>Eco Grass>old-man mason pine rehabilitation, the scores of these measures were: 0.6985, 0.6919, 0.6671, 0.6479, evaluation grades were good. The scores of ecological benefits from year 2000 to 2005 were 0.6419, 0.6275, 0.7372, 0.6393, 0.6543, evaluation grades were good, and the scores on the control area were 0.2962, 0.2615, 0.2649, 0.2555, and 0.2470. The total score of ecological benefits of research area in 2008 was 0.6647, evaluation grade was good. Ecological benefits increased significantly compared with that of the control area, which was 0.3186.