County-scale Research On Spatial-temporal Change And Management Of Land Ecology In The Context Of Urbanization

In recent years,the urbanization process is accelerating in china.While human develop and utilize land resources,it also profoundly changes the surface ecological environment.Urbanization will have a severe impact on land ecological change in the process of regional development,and how to coordinate the relationship between urbanization and land ecosystem has become a hot issue in the study of the current land resources science.Therefore,researches that focused on the dynamic evaluation of land ecology,along with the rule of its spatial-temporal change and identification of its main driving factors,are very important to the scientific management of land resources and realize coupling coordination development between regional urbanization and land ecology in the context of accelerated development of urbanization.Based on "phenomenon process-mechanism-practical application",this paper took Xuyi County of Jiangsu Province as the study area.We analyze the spatial-temporal variation law of the characteristics belonged to the regional land ecological evaluation index system,which is composed of land ecological foundation,structure,construction and degradation,in terms of the land ecological types,spatial association and spatial morphology as the first step.Then,we apply the econometric model to study the effects that urbanization paly on land ecological change and analyze the coupling relationship between them quantitatively.Based on these results,we construct overall pattern of the management for the study area,divide it into different land ecological management areas,and put forward different management strategies.The main conclusions of the study include the following:(1)The land ecological condition had got better before it became poor in study area from 2000 to 2010.Land ecological conditions of southwestern hilly region and northern Hongze Lake in Xuyi County were generally better than those of central plains region.Land eco-type was fluctuant in Xucheng town and the surrounding areas,while other areas with weak urban construction activities were relatively stable.According to spatial correlation analysis,along with the sector and concentric circles analysis,we find that land eco-index "low-low"concentration areas that are located in the main city and the surrounding places with the higher level of urbanization are relatively stable,while "high-high" concentration areas swing from southern hilly region with better land ecological background to northern Hongze Lake and the coastal areas repeatedly.During a decade,the decrease of land eco-index was consistent with the expansion of urban construction land in terms of each space direction.Furthermore,it shows an obvious rule of urban-rural gradient.(2)We identify the driving factors of land ecological changes though applying multiple stepwise regressions and path analysis,and the gray relational model is used to explore the spatial-temporal relationship between land ecology and urbanization in each town.In the past decade,the growth of urban per capita disposable income and proportion of secondary and tertiary industries in GDP,which represents the negatively effects that the economic development of urbanization play on the land ecological change is the most directly and significantly.The increase of the proportion of construction land area which means the land urbanization development shows a certain lag,and its indirect effect is greater than the direct drive.However,we did not find the evidence that the population urbanization play a role on the land ecological index change.Coupling degrees of the townships in the timing show fold rise and inverted U shaped variation,and the spaces were relatively stable in the low zones,while the areas with high value have experienced fluctuating processes which are from east to west and west to southeast.This suggests that the different stages of regional economic and social development,the antagonism,stress,constraint and coordinate role between the two systems are not the same and are in an unstable state of change.According to the coupling characteristics and driving factors,the overall development of the two systems is in an antagonizing period,but it can be relatively subdivided into four types:low coupling degree-high level urbanization,medium coupling degree-medium level urbanization,high coupling degree-low level urbanization and low coupling degree-low level urbanization.(3)We construct the land ecological overall four-wheel drive mode of the management in terms of resource saving,environmental protection,ecological industry and ecological protection.Through combining land ecological zones with coupling zones,the study area is divided into 4 primary partitions which include land ecology-urbanization coordinated management areas,running management areas,antagonistic management areas,low coupling management areas and 10 second-level partitions.Coordinated management zones should keep the existing scale of urbanization based on the optimization of land use pattern inside urban areas,speed up the eco-industrial park construction,and promote regional land ecological improvement.Running management zones should be adjusted to focus demands on lands which are used for urban development of key projects,following demands that surrounding major urban areas need on ecological functions.Antagonistic management zones shall be restricted in the extensive development of regional ecological land and focused on eco-tourism and other green services as the main developed direction,in order to ease the conflict between the two patterns.Low coupling management zones should control land use change,vigorously promote aquaculture processing and other associated secondary and tertiary industry development,and improve regional economic growth.