The Land Use Landscape Ecological Security And Optimization Research Of The Three Gorges Reservoir Area Ecological Barrier Belt

It is a hot and key point in the three gorges reservoir area of land use. As the mostcomplex areas of land use in the three gorges reservoir area, ecological environment ofecological barrier in The three gorges reservoir area is fragile, terrain is complex, it isthe focus of land use in reservoir area. In this paper, we choose Wushan, Fengjie,Yunyang, Wanzhou, Zhongxian, Shizhu, Fengdu, Fuling of ecological barrier in Thethree gorges reservoir area as the study area, With the support of GIS and RStechnology, we use land use diversity index and the evenness index for land use toanalyze land use status of the study area in2012; at the same time,we built the modelof ecological risk evaluation in the study area, security situation of land use of studyarea is studied, ecological risk and the reason and optimization countermeasures in thestudy area are discussed。(1)Different buffer distribution characteristics of land use in the study areaWith different distance from the Yangtze river on both sides trend of land use areashowed decrease trend from the near to the distant in the study area has: plantation,shrub grassland; trend of land use area showed increase trend from the near to thedistant in the study area has: forest land, open forest land. But, with the increase of theradius of road buffer area of various land use types change was not significant.(2)Landscape pattern analysis in the study areaTrends are consistent with the increase of the elevation and slope belt in diversityindex and evenness index of Land use in the study area，they both present variationtendency of first increases then decreases. Among them，land use diversity andevenness index reached the maximum in elevation with150-300m and slope belt in3-8°, the diversity index value were1.45and1.45, respectively, evenness index valuewere0.70and0.70, respectively. Diversity and evenness index in the study area to theminimum with the elevation in＞1500m and slope belt in≥25. the diversity indexvalue were0.23and0.86, respectively, evenness index value were0.11and0.41,respectively.(3)Land use and landscape pattern influence factor analysis of the study area The study area in300-500m,500-800m elevation has largest area and respectively17.15%and13.61%of the total area of the study area,in elevation area of300-500mopen forest land and arable land area are More than10%of the total area of the studyarea,0.3%in elevation area of500-800m area of cities and towns roads rivers swagsare all less than0.3%; The study area mainly concentrated in the various land use typein the slope belt of0-3°、3-8°and8-15°,the main three farming class for thin filling andforest land, farmland and forestland at the slope belt of0-3°, at the slope belt of3-8°main types of land use are forest land and opening, at the slope belt of3-8°maintypes of land use are forest land, opening, grass, plantation; The sandstone is themainly lithology in the study area, Plantation, forest land and open forest land are themainly land use types in sandstone region;Land use and landscape pattern of the studyarea presents a stripe and patchy distribution because of geomorphic feature innortheast is high and southwest is low. Cultural factors mainly reflected in urbanization,returning farmland to forest and grassland project, The three gorges immigrant project,industrial structure adjustment.（4）Spatial autocorrelation analysis and ecological risk assessment for studyarea.Low level area of ecological risk take the largest share of the ecological risk levelin the3044grid about23.74%of the study area. The main land use type arefarmland、woodland and shrub woodland. The high ecological risk area take the lowestpercent, just12percent.The main types of use are arable land, sparse shrub land andconstruction land.(5) The Optimization of land use.With the altitude and slopes change, the reasonable index of land use increased atfirst and then decreases in the end, when height goes to＞1500m and slope goes to0-3°reached the higheat index. Making the optimization strategies of ecological riskcharacteristics for study area. Enhancing the protection of origial land and adjusing thefarmland to obtain the best method of land about the study area.