Evaluation And Analysis Of Ecological Restoration Of Loess Hilly And Gully Region Based On Landscape Pattern Changes

Loess Hilly gully region has the characteristics of surface crushing, gully density and low vegetation coverage.Unreasonable land use make the land eco system face great pressure, such as predatory consumption of natural resources, serious soil erosion, Continuous degradation of the ecological environment.To grasp the current situation of ecological system, the degree of recovery and the direction of development, is the main content of ecological restoration project, also provide the basis for the adjustment and improvement of recovery scheme.This study based on landscape ecology, RS, GIS theory and method as a guide.Through field investigation, using GIS spatial analysis, GPS analysis and observation technology of remote sensing image processing, the remote sensing data sources were analyzed to determine the typical county in the Loess Hilly Region and small watershed as the study area.The county scale selection of 30 meters of TM remote sensing image as the data source, a classification of land use landscape types, analysis of land use change in 20 years.The small scale in the Daohugou loess hilly region and built fort of typical small watershed management as the representative, according to the division of the landscape type ecological restoration measures, catchment scale 2.5 meters high resolution remote sensing image, reveal the comprehensive watershed management, governance, to the current three time ecological restoration and landscape pattern the dynamic change trend of each landscape type.The ecological restoration evaluation model on county scale selection in TM image as data source, through the inversion of NDVI regional vegetation coverage, with the inversion of grassland biomass investigation services amendment value equivalent, the vegetation coverage and the change of ecological service value in two aspects of rapid and effective evaluation of regional ecological restoration benefits. Small watershed scale analysis and built Fort Hu Gou watershed Hu Gou watershed ecological restoration landscape pattern, landscape elements, landscape characteristics, patch size distribution, patch shape index, landscape diversity analysis and other aspects of analysis and comparison, and construct the model of soil erosion CSLE, provide the basis for rational use of natural recovery and resources for watershed ecology from the variation of soil erosion, different scales of analysis, can effectively reflect the benefits of regional ecological restoration, for the reconstruction of ecological environment in loess hilly region, biodiversity conservation and provide scientific basis for grassland resources and sustainable utilization of land resources and ecological landscape planning. The results show that:(1) 20 years, Pengyang County bare rocks and bare soil, the highest conversion rate, mainly to grassland and farmland conversion.1995-2000 advantage of the landscape as the farmland landscape, grassland landscape 2005-2015 years, the area has become a dominant landscape.2000-2005 land use in Pengyang county from the changes of the whole range is the biggest, fastest, this stage is to promote the rapid stage of forestry project, the impact of human activities on the natural environment greatly, grassland landscape increased rapidly in the period of 2010-2015 phase, the increase of urban construction land is the fastest of the class, reflecting the region affected by the impact of ecological immigration policy.2005-2015 years, the grassland landscape became the dominant landscape area. From the type of land use change in the study area, speed and other data are displayed from the corresponding period national forestry policy, ecological immigration policy and the policy adjustment is the main driving force of land use pattern in Pengyang county.(2) The sampling plots were basin herbaceous plants of 57 species belonging to 17 families and 35 genera. Of which 6 genera and 16 species of Asteraceae, Leguminosae 8 genera and 11 species,8 genera and 8 species of Gramineae, respectively of the total species number 19.29%,14.04%,28.07%, three families 22 genera and 35 species in total. The ditch there were 15 species in Gramineae and Compositae; gully slope gradient appeared a total of 18 plant species in Gramineae and Compositae; ridge slope gradient, there were 19 kinds of plants, the Gramineae and Compositae; tops the gradient there were 33 kinds of plants, Compositae, Gramineae, Leguminosae and Rosaceae mainly. Leymus secalinus, Stipa bungeana and Artemisia scoparia is Pengyang County small watershed sampling the dominant species, other dominant species change along the altitudinal gradient change. The biomass decreased with the altitude increasing, the ditch bottom gradient biomass level is the highest, followed by Liang Mao and Liang Mao gully slope, slope top is not much difference, spatial distribution difference is not obvious.(3)The study combined with the characteristics of Loess Hilly gully region, the county scale land use and land cover change through 20 years of ecological restoration benefits, at the same time, the application of scaling the sample data to deduce the county scale combined with survey data from the ecological restoration can reflect the quality of biological diversity and regional biomass spatial distribution. From the point of view of soil erosion landform zoning, statistical methods used measured data from sample scaling to the sampling of small watershed by landscape position expectation method to deduce the sampling of small watershed basin.Finally, through the terrain complexity of soil erosion will partition the entire watershed data scaling to the county the scale, summed up the new method combined with the ecological two aspects of quality and quantity recovery benefit evaluation.(4) Gao Jian Bao, Hu Gou watershed ecological restoration landscape space layout according to the terrain factor, the vertical distribution characteristics of gully tiger obviously. The altitude from low to high, the landscape components of the spatial distribution of the slope is greatly affected by distribution ratio were first gradually increasing and then decreasing trend; the slope from shady to sunny in the process of filling the distribution proportion of grassland, level terrace, mixed forest landscape and the distribution ratio decreases, the increase of forest ecological restoration of grassland vegetation, and gully erosion prevention forest landscape is not affected by the slope effect.