The Study Of Ecological Space Evolution And Restructuring In Chang-Zhu-Tan Urban Agglomeration

Ecological space is the important ecological barrier of guarantee of human society in harmony with the natural environment,which plays an important ecological function.With the rapid development of urbanization process and urban land expanding,ecological space has been squeezing,which lead to ecological function degradation and the deterioration of ecological environment.From the perspective of the landscape pattern-process-function,analyzing the theory and practice of urban ecological space evolution and reconstruction problem is the requirement of the construction of ecological civilization,which also is problems of geography,ecology and other disciplines scientific to be solved.By integrated using of GIS and RS technology,landscape ecology analysis technology,ecological process simulation and the related research technology,taking Changsha-Zhuzhou-Xiangtan urban agglomeration as the research area,choosing 1990,1995,1995,2005,2010,2013--a total of five years for the observation point,the following aspects are studied:(1)Ecological space in Changsha-Zhuzhou-Xiangtan urban agglomeration has been changed.It analyzed that ecological effect of ecological spatial scale change,landscape index change,spatial transfer and other characteristic,which affects the main natural,human factors and ecological spatial changes.(2)Ecological space of Changsha-Zhuzhou-Xiangtan urban agglomeration has been reconstructed.The principle,mechanism,effect and character of the ecological space reconstruction was presented,and the principle of ecological space reconstruction was proposed,and the strategy of ecological space reconstruction is discussed from different perspectives and different scales.The improved particle swarm-markov model has been built,which predicts the ecological spatial reconstruction of the long plant pond.The main research content and achievements are as follows:1.The changing of ecological space of Changsha-Zhuzhou-Xiangtan urban agglomeration has the following characteristics:reduction in total,from 1990 to 2013,total area were decreased by 332.19 km2.Processing of quantity change can be divided into:initial expansion,rapid decrease in the early stage,slow fluctuation in the middle period and rapid decline in the later stage;The ecological space area of Changsha city,Zhuzhou city and Xiangtan city continued to decrease;The largest proportion is woodland area,accounting for 86.47%in 2013.Landscape features are becoming more and more fragmented,with the number of patches increased from 51,799 in 1990 to 64,891 in 2013.The transfer characteristic of ecological space is obvious in Dongting lake area and the surrounding area of major cities.The area of the transfer area is greater than the transferred area,with the net decreased about 332.19 km2.2.The factors that affect the ecological spatial pattern of Changsha-Zhuzhou-Xiangtan urban agglomeration mainly include natural factors and social humanistic factors:The ecological space of the area with low elevation below 200 m and the area of 7000m in the near river and 8.000m in the near lake is changing rapidly;Social and economic development,industrial structure adjustment,population size and structure change,improvement of living standards and improvement of technology have an impact on ecological space change;The change of ecological spatial pattern can cause changes in river runoff,air quality and water environment quality.3.The ecological space reconstruction of urban agglomeration affects the ecological process.by changing the pattern of ecological space,thus exerting an influence on the development of ecological functions.Patch,corridor and matrix are the basic elements of ecological space reconstruction.Natural evolution,ecological security,space conflict,social transformation and human factors are the main reasons for ecological space reconstruction.Natural evolution process,artificial transformation process,natural and humanistic coordination and integration process are the basic process of ecological space reconstruction.Reconstruction of ecological space brings effect of climate,soil,hydrology and biological.4.The ecological space reconstruction of Changsha-Zhuzhou-Xiangtan urban agglomeration must follow the five principles of integrity,comprehensiveness,ecological security priority,local conditions and stability;Ecological space reconstruction strategy is different under different perspectives:From the perspective of ecological process,emphasis should be placed on flood inundation,biological processes and human activities;From the perspective of ecological process,emphasis should be placed on flood inundation process,biological process and human activities.The ecological interface should focus on urban and rural transition zone and mountain-plain transition zone.The implementation approach is different under different scales:At Macroscopic scale,reasonable optimization should be placed on "SanSheng" space layout;At medium scale,the ecological network system of reasonable structure,complete functions should be built;At the micro scale,it is necessary to rationally adjust the urban and rural local spatial structure of urban agglomeration,protecting the ecological environment,improving the quality of habitat and the diversity of landscape.5.The building method of the improved particle swarm-compound markov model are as follows:first,using the land use dynamic degree to improve the markov,which is used to predict the number of ecological space particles size;Second,take the ecological space of "source" and"corridor" as the constraint condition;Take the cell’s ecological space risk value as the fitness function of particle swarm model,using optimization operator to improve particle swarm,to predict the spatial layout of ecological space particles.By using this model to simulate the ecological space of the year 2020 old pool urban agglomeration,the simulation results show that the total area of ecological space,which will assume the overall reduction trend,with the reduced area reaching 98.46 km2.The cultivated land area of 269.75 km2 is transformed into the ecological space area,and the ecological space area of 159.69 km2 is converted into the cultivated area.The areas with obvious changes in ecological space are mainly distributed in the southwest.