Integrating CVOR-GWLR-Circuit Theory Model Into Construction Of Ecological Security Pattern Research In Yunnan Province

The construction of ecological security pattern,which can coordinate the prominent contradiction between ecological protection and economic development,is one of the effective spatial ways to ensure regional sustainable development and improve human well-being.As for the traditional construction of ecological security pattern,it is mostly based on the minimum cumulative resistance model(MCR)to extract the least cost path as the ecological corridor,and the ecological node is determined by manual discrimination.However,this method lacks consideration of the exchange process of energy flow,material flow and information flow,which results in a certain deficiency of ecological security pattern in structure and function.In order to solve the above problems,this paper characterized natural background data into localized correction variables,added them to the ecological security pattern construction model,proposed an ecological security pattern construction method integrating CVOR-GWLR-Circuit theory model,and took Yunnan Province as the research area.First of all,the“Contribution-Vigor-Organization-Resilience”(CVOR)ecological security evaluation system was constructed based on the importance of ecosystem services and ecosystem health,and the ecological security of Yunnan Province in 2000,2010 and 2020 was evaluated.Combining with the data of the nature reserves in Yunnan Province,this paper identified the ecological source according to the evaluation results.Then,the basic ecological resistance surface was constructed based on land use data and topographic factors,and the GWLR landslide sensitivity evaluation model was introduced to correct the basic resistance surface.Finally,based on the identification results of ecological source and resistance surface,the circuit theory model was used to extract the ecological corridor,and construct the ecological security pattern of Yunnan Province.The main research contents and conclusions are as follows:(1)Based on the results of the ecological security assessment,combining with the data of the nature reserves in Yunnan Province,this paper identified 96 ecological source patches.The ecological source area was about 69417.78km~2,which accounted for 17.6%of the total area of the study area and mainly included the forest land,cultivated land,grassland and shrubs.Among them,forest land was the most significant,accounting for 69.6%of the total area of ecological source land.(2)The landslide susceptibility of Yunnan Province was evaluated based on the GWLR model and the MaxENT model.The accuracy of the two evaluation models was89.6%and 80.4%,respectively.Therefore,the basic resistance surface was revised based on the evaluation results of the GWLR model,and the resistance value of the revised resistance surface was significantly reduced,which could be more conducive to the migration of species.Moreover,the boundary between high and low values was more significant and clear.The high-value areas were mainly distributed near the plateau lakes in Yunnan Province,Dianchi Lake and Fuxian Lake in central Yunnan,and the Erhai Basin in the Western Yunnan Province.(3)The circuit theory model was adopted to extract 780 ecological corridors,which are in the shape of“spider webs”,linking southwest,northwest,northeast,central and southeast Yunnan Province,and the spatial distribution of the province was significantly different.In this research,36 ecological pinch points had been identified,with a total area of 25141.8 km~2,mainly distributed in Nujiang Prefecture and Diqing Prefecture in northwestern Yunnan,Kunming City and Chuxiong Prefecture in central Yunnan,Lincang City,Xishuangbanna Prefecture and Pu'er City in southwestern Yunnan,and Zhaotong City in northeastern Yunnan.There were 42 ecological obstacle points with an area of 21591.2 km~2,which were mainly distributed in Nujiang Prefecture,Dali Prefecture,Chuxiong Prefecture,Kunming City and Qujing City in central Yunnan,and Honghe Prefecture in southeast Yunnan.Overall,Yunnan Province presented a multi-point ecological security pattern of“three screens,two belts and six corridors”.(4)Compared with the traditional method of constructing the ecological security pattern based on the minimum cumulative resistance model,the method of constructing the ecological security pattern by adding the localized characteristic variables and integrating the CVOR-GWLR-Circuit theory model has more advantages,which can be mainly manifested as follows.To begin with,the identified ecological security elements are more objective,which solves the problem that the impact of terrain factors and natural disasters on the resistance surface is not fully considered in the previous studies when the resistance surface is constructed.In addition,the constructed ecological security pattern is more reasonable,which can not only reflect the specific scope and key nodes of the ecological corridor,but also make up for the problem that the minimum cumulative resistance model ignores the randomness of biological walking and cannot identify the true width of the corridor.