Pattern Optimization Of Urban Expansion On The Basis Of Land Ecological Suitability

Urbanization is the necessary way for China to achieve modernization,recent 30 years of rapid development urbanization has played an important role of promoting economic and social development and urban construction.At the same time,high-intensity land development and irrational land use activities has made the ecological space protection facing greater pressure,which affects the sustainable development of our city.In the context of new national urbanization planning and construction of ecological civilization,how to coordinate the space from urban expansion and ecological protection and improve the pattern of land development has become an urgent and realistic issue.The land ecological suitability evaluation could make a guidence to solve the above problems,because it concentrate on researching the suitable ecological protection area and the suitable city development area in the city.Based on the land ecological suitability to optimise the future urban expansion pattern is an effective way to coordinate the conflict between social economic development and ecological environment.The in Wujin District of Changzhou City as the study area.Firstly,it analyzes the characteristics of urban expansion in recent years,then based on the unit area ecosystem service value equivalent and landscape pattern index,it analyzes the ecosystem service value change and ecological landscape pattern change in Wujin District.Secondly,combining the vertical ecological process and the horizontal ecological process,through the multi factor integrated superposition,the minimum cumulative resistance model to evaluate land ecological suitability.Finally,CA Markov model was applied to simulate and forecast the urban expansion pattern of Wujin District according to the trend of inertia,and to optimize the urban expansion pattern based on the land ecological suitability zoning.The main research contents and conclusions are as follows:(1)Urban Expansion and its Environmental Effect Analysis:Firstly,by analyzing the scale characteristic and the layout characteristics of urban expansion of Wujin District in recent years,it finds that the urban expansion intensity gradually slows down and the expansion pattern clustering significantly,especially the city center presented the "pie" type of development trend.Then,by calculating the ecosystem service value,ecological landscape pattern index,it reveals the ecosystem service value decreased significantly and the ecological landscape increasingly fragmentation because of the urban expansion.(2)Land ecological suitability evaluation.First of all,by using the multi factor comprehensive superposition method to evaluate the vertical process of ecological suitability of the ecological protection land and urban land;on this basis,combined with GIS spatial analysis techniques to calculate the ecological minimum cumulative resistance value of the ecological protection land and urban land which was described the horizontal ecological process,and according to the minimum cumulative resistance difference surface,Wujin District is divided into four grades of land ecological suitable partition,each partition of the development strategy is put forward.(3)Pattern optimization of urban expansion:Firstly,taking the urban expansion process from 2008 to 2011 as a basis for simulation of 2014 urban spatial distribution,after precision evaluation and verification,taking 2014 as a basis for simulation of 2020 urban spatial distribution.It can be seen from the center of the city and town continues to expand and erode the ecological land.Base on the land ecological suitable evaluation results,urban expansion pattern of 2014-2020 ecological suitability to be analyzed to determine the pattern of different partition of the optimization strategy.Finally,the urban expansion pattern to be optimized.Cultivated land,garden land,forest land occupation was significantly reduced through the optimization of urban expansion pattern,it is conducive to the maintenance of Wujin District ecosystem service value and the ecological landscape pattern,and coordinate the urban development and ecological protection in the future,optimize land space development pattern.