Study On The Ecological Security Evaluation And The Construction Of Ecological Security Landscape In The City Of Zhengzhou

Ecological security is critical in ensuring the sustainable development of cities.However,as the process of urbanization speeds up,human activities have taken heavier toll on the ecological environment,severely threatening the regional ecosystems.Ecological security evaluation and the construction of ecological security landscape are essential research contents in exploring urban ecological security changes and the optimal allocation of spatial elements as they offer the scientific basis to put into perspective the dynamics of urban ecological security and the construction of urban ecological security landscape,which are of great significance to regional ecological security protection.The city of Zhengzhou was chosen as the research area in this paper,and the ecological security situations and their changing trends in Zhengzhou in 2000,2010,and 2018 were analyzed using the ecological security comprehensive index method.Based on the ecological security evaluation results,the ecological source was selected,the minimum resistance model was adopted to establish the minimum cumulative resistance surface,and the buffer zone,ecological corridor and ecological node were identified accordingly to construct Zhengzhou’s ecological security landscape.Main research findings are as follows:(1)In 2000,2010 and 2018,the ecological security in Zhengzhou were at secure,secure,and relatively secure levels respectively,showing sharply deteriorating ecological security;the reduction of area at secure level were mainly replaced by the increase of area at relatively secure,critically secure,relatively insecure and insecure levels.Among all administrative regions of Zhengzhou,Dengfeng enjoys the highest level of ecological security,followed by Gongyi City,Zhongmu County,Xingyang City,Xinmi City,Xinzheng City,and municipal districts;municipal districts suffer from the worst deterioration of ecological security levels,followed by Xinmi City,Xinzheng City,Gongyi City,Xingyang City,Dengfeng City,and Zhongmu County;the municipal districts went through the most rapid deterioration,followed by Xinzheng City,Gongyi City,Xinmi City,Dengfeng City,and Zhongmu County,Xingyang City.During the period from 2000 to 2018,the spatial and temporal change of ecological security level has three distinct characteristics.(2)A total of 31 ecological source plaques with a total area of 159231hm~2 were selected in this paper,making up 21.22%of the city’s total area;three types of buffer zones:ecological buffer zone,ecological transition zones,and development and construction zone were identified.The areas of the ecological buffer zone,ecological transition zone,and development and construction zone are 271549hm~2,184441hm~2,and 135072hm~2 respectively,accounting for 36.19%,24.58%,and 18.01%of the city’s total area.35 ecological corridors with a total length of 267km and 18 important ecological nodes were also identified to construct the ecological security landscape of Zhengzhou.(3)With the protection and construction of the key part of the ecological security landscape as the starting point,four countermeasures,including strengthening the protection of the ecological source,stepping up the construction of ecological corridors,reshaping ecological nodes,and land planning of buffer zones at different levels were proposed to offer a frame of scientific reference.