Research On Ecological Security Evaluation And Ecological Entropy Of Dujiangyan Region Based On RS And GIS

Ecological environment is a complex and sustainable development system relate to society,economy and natural,and it contains all resource have an effect on the human survival and development as biological,land,water and climate.The security situation of ecological environment system affects the sustainable development of whole ecosystem,and ecological security research has become the key of regional ecological construction.Due to Dujiangyan have special geographical location,prominent features such as natural disasters,human activities,and fragile ecological environment.It is great importance and value to study the situation of the ecological security in the region analysis and evaluation.In this essay,based on remote sensing image data,DEM,meteorological data and social economic data,etc.,with the support of ENVI,ArcGIS and Fragstats software,the integrated evaluation method was used for evaluate the ecological security situation in time and space of Dujiangyan region,which is located in Sichuan Province,and ecological energy conversion between centers studed by ecological entropy.The prime work and results are listed as follow:(1)Through the analyse of the characteristics about Dujiangyan's ecological environment,based on the theory of PSIR model to study remote sensing image and other data of Dujiangyan in 1994 and 2016,choose on the topography,climate,vegetation,land use,landscape ecology and the social economy as evaluation index from the six point,and establishing index system.(2)Standardizating used by the different levels standardization and the poor grade standardization,using entropy method and analytic hierarchy process to determine the index weight,and then calculate comprehensive index by the comprehensive evaluation method to evaluate the ecological environment.Results show that the average composite index is 0.564,better ecological environment,mainly in ? level and ? level in1994,and in 2016 averages became 0.439,the ecological environment quality decline,? level and ? level range decreases,the trend will be poor,scale in dynamic will change,and each level boundaries between apparent.In 1994,the overall ecological environment was better,the vegetation coverage was high and human activities were less.In 2016,the vegetation coverage decreased obviously and the ecological environment deteriorated in the northern mountain.(3)Through the network technology of geographic information,ecological entropy is used to describe the degree of interaction of ecological environment in different towns.The comprehensive ecological entropy value of each township is calculated,and analyze the situation about inward and outward transfer of the research area.In addition,study the ecological entropy change in Dujiangyan based on distance,NDVI,terrain undulating degree,and the ecological entropy decreases with the increase of distance,namely,the more energy is consumed by distance.The less ecological entropy be converge because of higher vegetation coverage,then smaller the impact will be.The terrain undulation is inversely proportional to the ecological entropy.