Comprehensive Affects Evaluation Index System Of Returning Farmland To Forest In Loess Plateau

Loess Plateau is one of region in China which conflicts are most concentrated in population,resources and environment,and also is the world's most serious soil erosion areas,which soil erosion area is 81.8% of the total area. As a improvement project to change the eco-environment,returning farmland to forest, achieved a certain degree of success from its beginning. Along with the ongoing projects, the ecological and socio-economic benefits are concerned by the people. How to assess the Loess Plateau to return farmland to forests comprehensive affects also become the major social problems. This research begins with the construction of returning farmland to forest comprehensive affects evaluation index system in different ecological regions of Loess Plateau, which is the first important step in the project benefits evaluation. Firstly provide scientific decision basis to the smooth implementation and sustainable development of the returning farmland to forest project in Loess Plateau. Secondly perfect and enrich the discipline theory of the returning farmland to forest project.Firstly,according to the different conditions of climate,soil,vegetation and geological background in Loess Plateau,this research divides Loess Plateau into 4 different ecological zones: Region of returning farmland to forest in hilly-gritty loess land; Region of returning farmland to forest in hilly-gully land of Loess Plateau; Region of returning farmland to forest in table-gully land of Loess Plateau; Region of farmland and forest-net in valley land of Loess Plateau. Rational division is the foundation of the returning farmland to forest comprehensive effects evaluation. Secondly,according to the affects returning farmland to forest to the environment and socio-economic in Loess Plateau, uses the typical survey and statistical methods,collects socio-economic data from year 1999to 2004 in Ansai. Use sentinel experimental and statistical data combined approach to collect eco-efficiency index, finally select the most representative of the Loess Plateau project efficient factors as indicators. From the two aspects,ecological and socio-economic benefits, chooses 8 elements layer, 28 indicators related to the effectiveness of projects to construct comprehensive effects evaluation system suitable for Loess Plateau region. Last,according to the steps of AHP, seek from advice from the experts in the field, and according to different ecological environment of Loess Plateau region, establish first, second third evaluation modules from target layer to index, calculates the weights of each index in each evaluation, and finally calculates the factor weights in four different ecological regions of Loess Plateau. In the evaluation index in four different ecological regions,index vegetation cover occupies a high proportion,which is in accord with the goals of returning farmland to forest. Other indicators weights reflect accurately of the actually environment of each ecological region. When we evaluate the returning farmland to forest comprehensive benefits in one area of Loess Plateau,judge which regional ecological types it belongs to,acquire the numerical evaluation indicators,Then we can evaluate the returning farmland to forest comprehensive effects in this region.