Research On Regionl Land Ecological Security In The Context Of New Urbanization

Land ecological security is the basis of regional ecological security,the limitation of land resources is one of the key problems of sustainable development.As China’s industrialization and urbanization,the contradiction between people and land have become increasingly prominent,extent of land use has been achieved,even exceed the regional ecological carrying capacity of land ecological system,resulting in the deterioration of the regional ecological environment,land ecological security has become a serious challenge.Under the background of urbanization,land ecological security research is imperative.At present,China is in the key stage of the implementation of the new urbanization development strategy,constructs the theory and method of land ecological security under the background of new urbanization has become an important subject to be studied urgently.Wuhan is the core city of Wuhan city circle,and also one of the central cities of the country.At present,Wuhan is facing the dual pressures of economic development and ecological protection,study the urbanization and land ecological security problems of this region systematically,also has more important practical significance for Wuhan and Wuhan urban agglomeration,will contribute to the maintenance of land ecological security,the implementation of new urbanization strategy,and construction of ecological civilization.Based on the theoretical study,this paper takes the DSR model as the basic framework.It evaluates the status of the regional land ecological security and the driving forces for status changes under the background of urbanization.Finally,it puts forward some strategies to improve the land ecological security level,to realize coordination development between urbanization and land ecological security.This paper mainly includes several parts as follows:(1)Theoretical basis analysis.The related concepts of the new urbanization and land ecological security are defined.The basic connotation of the person-land relations theory,sustainable development theory,system theory and theory of ecological carrying capacity are demonstrated.Their application in the research guide is analyzed.(2)The structure of land use system in Wuhan.Significant changes have taken place in the land use structure of Wuhan: the area of cultivated land decreased sharply,and the area of construction land expanded rapidly.The land use structure of Wuhan showed the characteristics of obvious spatial differentiation.Land use structure change in Wuhan is accompanied by the increase of information entropy and equilibrium degree.The evolution of dynamic structure is in accordance with the change of land use.It shows that the influence of the behavior of the regional land use on land use system gradually increases with the change of land use structure.The spatial difference of land use structure information entropy shows that the urbanization and industrialization of different districts of Wuhan,and economic development pattern are in different stages.The different emphasis and direction of land use causes the differences of land use structure information entropy in various districts.The main urban areas have the information entropy which was not consistent with other districts.The main reason for this is that the area is the core area for the development of urbanization and industrialization.The focus of land use is clear.land to construction land,high degree of dominance,other land types accounted for the low proportion of land use.The system is in a low level in an orderly state;other districts due to land use of different types,showing the different features of the information entropy.Construction land takes the great proportion in land types.Degree of dominance is high.Other land types account for the low proportion.The land use system is in a low level in an orderly state.Other districts show the different features of the information entropy due to different land use types.(3)Evaluation of land ecosystem services in Wuhan.Based on the ESV model,the service value of land ecosystem in Wuhan was calculated.During the period of2002-2012,the value of land ecosystem services in Wuhan city has experienced the ups and downs.The total service value of the land ecosystem in Wuhan increased.From the changes of service value in various land use types,service value of water is always the highest.The growth of forest service value mitigate the loss of regional land ecosystem service value brought by the decrease of cultivated land area,protecting the increase of the total value in Wuhan city during the study period.The change trend of water and the change of the total value of regional ecosystem services are basically the same,which changed from up to down.From the single function of service value,hydrological adjusting function in Wuhan city is in the leading position.food production and waste treatment service value decrease in total.Other functions are improved in different degrees.Land ecosystem service value in Wuhan city has obvious spatial differentiation.Jiangxia district and Huangpi belongs to the high value area.Xinzhou District,Caidian district and the city belongs to the median area.Dongxihu District and Hannan belongs to the low value area.(4)Comprehensive evaluation of land ecological security in Wuhan.The comprehensive evaluation of land ecological security is a comprehensive decision process.It includes several steps,such as the index system construction,the determination of the index weight,the judgment of the ideal value of the index,the establishment of the evaluation model,the classification of safety level and the analysis of the results.Comprehensive evaluation results show that the level of land ecological security in Wuhan shows a slow upward trend and the land ecological security level gradually increases in 2002-2012 this time.Overall,the level of land ecological security in Wuhan is limited,and the problem of regional land ecosystem has not been fundamentally solved.Land ecosystem is still under great pressure.The level of land ecological security was increased from grade II to grade III critical safety level,which indicated that the ecological security situation of regional land was alleviated.The structure and function of the land ecosystem have been optimized,but they still face a large land ecological risk.The level of land ecological security in Wuhan has gone through two stages: for the regional land ecological security risk stage from 2002 to2008 and the regional land ecological security critical safety stage from 2009 to 2012.Due to the differences in the security level of each subsystem,the coordination of land ecological security in Wuhan gradually reduces.(5)The driving force analysis of regional land ecological security.The coordinated development degree of urbanization and land ecological security level of Wuhan city in the period of 2002-2012 showed a progressive evolution from low to high.The type of coordination evolved from a low degree of coordination to a high degree of coordination.The results show that the level of urbanization and the level of land ecological security in Wuhan tend to increase simultaneously,and the interaction intensity between the urbanization system and the land ecological security system is increasing.Interaction tends to be reasonable.From the time dimension,the land ecological security barrier factor is in the dynamic change in the factor category,order and obstacle degree.From 2002 to 2012,the change of Wuhan land ecological security barrier factor experienced from all the fixed assets investment,economic density,per capita GDP and other economic factors to industrial solid waste emissions intensity,percapita arable land,water resources per capita and per unit area of farmland fertilizer load resources,environmental factors.It shows with the development of economy and society,the problem of resource and environment has gradually become the bottleneck of regional land ecological security,which is basically the same as the process of urban development and land ecological security in Wuhan.From the point of view of the target level of barriers,the degree of economic security barriers showed a significant downward trend.Social security barriers showed a downward trend.Resource security and environmental security barriers showed an upward trend.With the development of economic and social development and the deterioration of resources and environment,environmental security and resource security have become the main obstacles to the ecological security of Wuhan.The EKC model was used to simulate the regression curve of driving factors and land ecological security index.The results showed that most of the factors had significant correlation with the land ecological security index.Explaining the urbanization process is an important factor to cause the change of land ecological security level in Wuhan.The best fitting model of driving factors and land ecological security index was established,and the regression parameters and fitting curves showed that the relationship between the driving factors and the land ecological security index did not accord with the law of EKC.The main reason is that the level of land ecological security is affected by natural,economic and social factors,and the land ecological security index is a comprehensive judgment result after multi-index weighted superposition,and there are great influence about selection of driving factors and regional differences.With the development of economy and urbanization,the ecological security level of land tends to increase.Economic development and urbanization process is not necessary factors to hinder the improvement of land ecological security level,the sustainable development of economy and the development of urbanization should be important way to weaken the ecological risk and realize the structural stability and function optimization of land ecosystem.(6)Research on countermeasures of land ecological security in Wuhan.Based on the obstacle factor diagnosis,and the coordinated development of urbanization and land ecological security,this paper puts forward the countermeasures of regional land ecological security.Aiming at the obstacle factors,it put forward countermeasures from“three wastes” prevention and treatment,protection of land resources,intensive landutilization,water resources management etc.It gives some recommendations from the aspects of "three lines" delineation mechanism and tripartite collaborative synergy mechanism for the coordinated development of urbanization and land ecological security.