Evaluation Of Ecological Connectivity Based On The Minimum Cost Distance Model

Ecological connectivity is the key to maintain the integrity and stability of the ecosystem and the sustainable development.It is also a hot research direction of landscape ecology and an effective way to solve the problem of landscape fragmentation,which maintain,rebuild and restore the landscape function.But most of the researches are on the landscape index:It's hard to show up in space.While using the least cost distance model can not only to analyze the changes of the ecological connectivity in space,and make the evaluation results more intuitive and reasonable than landscape index method.Therefore,this study takes the Xishan District as the study area.Based on the principle of sustainable development of land use and landscape ecology.For the first time,using the least cost distance model to evaluate the ecological connectivity of the land use in Xishan District,and to explore the driving force of the change of the ecological connectivity.According to the evaluation results,combined with economic development and actual society of the study area,put forward new ideas to optimization and improve land-use planning of Xishan District,improving the adjustment and improvement of planning more forward-looking,scientific,and ecological adaptability.The main research as below:(1)Analysis of temporal and spatial variation in land use and landscape pattern of Xishan DistrictThe analysis base on land use data of quantity changes,changes of intensity and contribution rate in 2009,2015,2020.Using the software of landscape index analysis to discuss the corresponding period of landscape changes.The following conclusions are obtained:the land use change of Xishan District in 2009-2015 years showed the first increase and then decreased.The comprehensive dynamic degree of land use was 1.23%in 2015.In 2009,the dynamic degree of land use was 1.52%.This analysis result of landscape pattern index in Xishan District showed that the landscape fragmentation of Xishan District in 2009-2015 years was rising,and then it will be better in 2015 years.Analysis results of type level pattern index showed that during 2009-2015 years urban and rural construction land,cultivated land,natural reserves tend to be fragmental.After 2015,the degree of fragmentation increased in other construction land,garden plot,traffic and water land.(2)The evaluation of ecological connectivity in Xishan DistrictThe evaluation of ecological connectivity using the least-cost model and ArcGIS technology,based on the 2009,2015,2020 three land use and planning database.Establishing resistance value by calculating ecological service value in different ecological function areas and get the BEI and ECI.The evaluation results showed that the landscape connectivity of Xishan in 2009 was decreased,and the degree of landscape fragmentation increased,which was consistent with the results of 2009-2015.The main reason is due to the Xishan economy rapid development during the 12th Five-Year Plan period.A large number of construction land,transportation and water land increased,resulting in the urban green space is divided,some farmland occupied and other conditions on the ecological environment caused a negative impact.Ecological connectivity has improved in 2015 to 2020.It's mainly due to the importance of ecological protection during the 13th Five-Year Plan period and have a vital catalytic role for the ecological environment of Xishan by establishing a large number of scenic spots and ecological wetlands.However,the related facilities of transportation and water land and the popularity of Farm Tourism in lakeshore of Dian the lake caused the fragmentation of the landscape in some areas.(3)The study of landscape optimization and countermeasure in Xishan DistrictAccording to the evaluation result of ecological connectivity,adjusted the ecological function area of Xishan by the deep analysis with land use data in three periods.which is divided into 5 function regions:forestry ecotype,tourism area,industrial economic area,lake protection area and the urban construction area.The development direction of each function area is combined with the practical development in Xishan.For the industrial economic area and the urban construction area with serious ecological landscape problems,we can optimize the landscape pattern and improve the ecological function by planning 3 ecological corridors.Finally,which aims at reasonable layout of construction land and strengthen the protection of the ecological.Putting forward appropriate countermeasures with land use planning in four sides:control the pollution in Dian lake,Scientific development and utilization of forest resources,the Protection of Basic Farmlands,economical and intensive use of land.In order to provide a scientific guidance for the adjustment and improvement of the overall land-use planning.