Research On Key Technology Of Vulnerability Quantitative Evaluation For Multi-type Ecological Functional Areas

With the severe change of climate and the stress of human activities,the ecological environment of different types of ecological function areas in China has been seriously damaged,and ecological vulnerability is a hot issue in the current regional environmental change and sustainable development research.However,most of the current research methods are suitable for a single type of ecological function areas,while the research on ecological vulnerability applicable to multi-type ecological function areas is relatively small.Therefore,this study will focus on Sanjiangyuan grassland meadow wetland ecological function area,Hunshandake desertification control ecological function area,Chuandian forest and biodiversity ecological function area,Guiqiandian karst rocky desertification control ecological function area,considering the ecological characteristics and index characteristics of each ecological function area,constructing the evaluation index system of different types of ecological function areas by using the SPR model,and then the dynamic weight determination method was used to assign weights to the influencing factors of different types of ecological function areas and different historical periods.At the same time,NPP index was introduced to define the ecological vulnerability threshold of multi-type ecological areas,and the spatial distribution characteristics of ecological vulnerability of different types of ecological function areas were analyzed,the driving mechanism of ecological vulnerability of different types of ecological function areas was analyzed by using geographical detectors.The specific research results are as follows:(1)Vulnerability assessment system and weight assignment scheme for multi-type ecological function areas based on dynamic weighting method have high applicability.At the same time,the threshold definition of vulnerability classification based on NPP can better unify the ecological vulnerability assessment results of different ecological areas to a comparable level.(2)The average ecological vulnerability of ecological function area in Sanjiangyuan is mildly vulnerable,showing a spatial distribution pattern of high in northwest and low in southeast.The average ecological vulnerability of Hunshandake ecological function area belongs to mild vulnerability,the ecological vulnerability is high in the west and low in the middle east.The average ecological vulnerability of Chuandian forest and biodiversity ecological function area belongs to mild vulnerability,and the overall ecological vulnerability is low.The average ecological vulnerability of Guiqiandian karst rocky desertification control ecological function area is mildly vulnerable,and the spatial expression is that the northwest is relatively vulnerable and the central and southern ecological environment is better.(3)During the period from 2000 to 2018,the area of the slightly vulnerable area in the Sanjiangyuan ecological area changed most obviously,and the area of the slightly vulnerable area increased by 8.65×10~4km~2 in 2018.The area of mildly vulnerable areas in the Hunshandake ecological area has the most obvious change,compared with 2000,the area of mildly vulnerable areas decreased by 2.59×10~4km~2 in 2018.The area of the moderately vulnerable area in the Chuandian ecological area has the most obvious change,and the area of the moderately vulnerable area increased by 0.96×10~4km~2 in 2018.The Guiqiandian ecological area is also the most obvious change in the area of the moderately vulnerable area,compared with 2000,the area of the moderately vulnerable area decreased by 0.92×10~4km~2.(4)Temperature,precipitation,vegetation cover type,land use type,slope and altitude all affect the spatiotemporal distribution pattern of ecological vulnerability in different types of ecological functional areas to a certain extent.The dominant factor of ecological vulnerability in the Sanjiangyuan ecological area in 2000 and 2018 was vegetation coverage,while the dominant interaction factor changed from vegetation coverage∩precipitation to vegetation coverage∩temperature.The dominant factor of ecological vulnerability in the Hunshandake ecological area is precipitation(2000)→vegetation coverage(2018),and the dominant interaction factor is vegetation coverage∩NPP(2000)→vegetation coverage∩sunshine(2018).The dominant factors of ecological vulnerability in the Chuandian ecological area are all vegetation coverage,while the dominant interaction factor is vegetation coverage∩elevation(2000)→vegetation coverage∩sunshine(2018).The dominant factor of ecological vulnerability in the Guiqiandian ecological area is NPP(2000)→precipitation(2018),and the dominant interaction factor is vegetation coverage∩precipitation(2000)→vegetation coverage∩elevation(2018).