A Study Of The Evolution And Adjustment Of The Ecological Security Pattern Of The Polarized Areas

As an important strategic area for China‘s regional development,the polarized area bears the important task of promoting regional development.China has established nearly 20 polarized areas,which have played a key supporting role for economic development and regional rejuvenation.However,with the agglomeration of factors and economic development,the situation and pattern of ecological security has been deteriorating in these regions,which is already a hot topic of concern and research in the academic and government sectors.The Wanjiang City Belt is a developing polarized area with the advantages of policy support,traffic location,and excellent resource endowments.It has made great strides in industrial economic development,urban system construction,and infrastructure upgrading.However,polarization has triggered rapid changes in land use from agricultural land to construction land,key ecological conservation resource atrophy in landscape patterns,and the weakening function of ecological service.Thus,the regional ecological security pattern is facing new challenges.The study collected data on multi-period and long-term land use image interpretation of the Wangjiang City Belt,and obtained natural ecological attribute data such as DEM,precipitation,topography,and vegetation cover,as well as socio-economic development data in the region,using theoretical induction and reasoning,combining empirical and comparative,qualitative and quantitative methods,based on the GIS platform,integrating application of MCR,DPSIR model,spatial autocorrelation,hotspot analysis and mathematical statistics and other methods to develop the evolution and effect research on polarization area ecological security pattern.In reference to the existing research results at home and abroad,a concept model for the evolution of the ecological security pattern in polarized areas was first proposed,combined with the process and characteristics of the development of polarized areas in China.In the model,it is considered that the polarized area develops and agglomerates various elements and economic activities.They are concentrated in a specific geographical space and become the source of interference that triggers the evolution of the ecological security pattern.And these trigger direct response,indirect response,and systematic response in turn(land use change,landscape pattern evolution,ecological risk increase and service value reduction etc.).The occurrence of these responses also follows the law of Distance Attenuation,Aging Lag,etc.The various ecological responses triggered have both the characteristics of temporal evolution and the laws of spatial differentiation.Land use change is the direct and earliest response triggered by the development of polarized areas.The main features of land use changes triggered by the development of polarized areas in the Wanjang City Belt in the past 20 years are the large absolute amount but low proportion,the paddy fields in the plain area have been reduced most,and the urban land has increased most.Below 200 meters above sea level and below 15 degrees,it is the geographical space where land use changes are most concentrated.The strongest expansion of construction land and hot spots are mainly in the urban areas with rapid economic development in Hefei,Wuhu,Ma‘anshan and Tongling.Landscape pattern evolution is also one of the contents of direct ecological security pattern response in polarized areas,and it is also the result and direct reflection of land use change.The landscape elements in different size and shapes caused by Wanjiang City Belt polarization development rearrange and regroup in the space.The landscape pattern shows the complicated and agglomerated characteristics,natural landscape become weak and fragmented,and some parts of the original ecological system gradually lose the original landscape;landscape patches show the center of the three significant blocks in Hefei City,Wuhu City and Yixiu District in Anqing City and the landscape diversity presents the distribution pattern of the north-south high,intermediate low,landscape evenness index shows obvious zonal distribution characteristic;the quality of landscape ecology is decreasing year by year,but the overall quality of landscape ecology is still at a safe level.The indirect response triggered by the development of polarized areas is mainly the change of ecological risk and ecological service value.The ecological risk of the Wanjiang City Belt has risen steadily over the past 20 years,and there are obvious spatial differences.The areas with significantly increased ecological risks are Hefei,Wuhu,Ma‘anshan and Tongling.There are no major changes in the Dabie Mountains and the Mountains area of South Anhui.These areas with increased ecological risk are mainly in the low-altitude and low-gradient plains and hills.The polarization characteristics of the distribution of ecological risks in the region are obvious.The total amount of systematic ecosystem services in the region presents a ?W?-shaped wavy change.Since 1995,the value of ecological services has been continuously increasing,rising to the top in 2005 and declining after it.In 2015,the total value of ecological services returned to the level of 1995.The rising ecological risk caused by polarized areas and the change in system service value are not completely synchronized in time and space.The response of polarized systems is reflected in the feedback and evolution of the socio-economic-natural ecological system.This paper uses the ?Driving Force-PressureState-Influence-Response? model and establishes a multi-level polarized area ecosystem safety indicator system for ecological safety assessment.The study finds that the average development level of the ?Driving Force-Pressure-State-Influence-Response? subsystems in the Wanjiang City Belt was relatively stable over the past decade.Among them,Hefei,Tongling,Ma‘anshan,Chizhou and Lu‘an have dramatic fluctuations in some subsystems.The share of ?driving force? and ?pressure? subsystems in most prefecture-level cities tends to decline in different degrees,and the ecological security system is in an early warning state.In Hefei and other cities along the Yangtze-River in Anhui,where the economy is developing rapidly,the ecological driving forces and pressures are relatively high,and it needs focus and coordination.In response to changes in the multi-level ecological security response that occur in polarized areas,the MCR model and GIS spatial analysis module were used to establish the ecological source,strategic points,and ecological corridors of the Wanjiang City Belt,and the spatial differentiation of the ecological safety area was identified.In addition,it constructed the main framework of the ecological security pattern in the Wanjiang City Belt and delineate the three major ecological source areas and seven major ecological corridors.In the township street space scale,based on the evaluation and recognition results of ecological security zones,the pre-determined spatial control zones were divided,and four types of towns and townships were designated for key development,optimized development,restricted development,and banned development.Finally,relevant countermeasures for future regional ecological protection and development are proposed.On the one hand,this study proposes a conceptual model of the evolution of the ecological security pattern in polarized areas,which is conducive to the promotion of theoretical studies on polarized areas and ecological security;On the other hand,this article conducts a comparatively in-depth and comprehensive empirical study on the Wanjiang City Belt,which has certain practical and theoretical guiding significance for Anhui to participate in the construction of the Yangtze River Economic Belt and protect the Yangtze River.