| The ecological protection and high–quality development of the Yellow River Basin have become major national strategies.To achieve high–quality development,it is necessary to continuously improve the quality of human life while safeguarding the ecological harmony within and around the area and advancing the sustainable development of the basin.The fragile ecological environment of the Yellow River Basin,prone to soil erosion and flooding,provides an opportunity for quantitative evaluation of the vulnerability of the Yellow River Basin and the study of ecological vulnerability with the strategy of harmonious human-nature development as the main research object.Hehuang area is situated in the upper reaches of the Yellow River,is located in the Qinghai–Tibet Plateau,Loess Plateau and Inner Mongolia Plateau transition zone,is the eastern monsoon region,northwest arid semi-arid region,and the Qinghai–Tibet Plateau area of the intersection,and is a complex area of agriculture and animal husbandry,the ecological environment is extremely sensitive and fragile.Therefore,it is of great practical significance to evaluate the ecological vulnerability of the Hehuang area.This paper constructs the ecological vulnerability evaluation index system based on the concept model of "exposure–sensitivity–adaptability",uses the projection tracing model combined with a genetic algorithm to determine the index weights,and calculates the ecological vulnerability index of the Hehuang region.The spatial and temporal patterns of ecological vulnerability in the Hehuang area were analyzed by using spatial and temporal scan analysis and spatial and temporal change analysis to explore the spatial aggregation characteristics and spatial and temporal change patterns of ecological vulnerability.The paper explores the influencing factors of ecological vulnerability through geographical detectors.According to the transformation characteristics of different vulnerability types,ecological vulnerability zones are divided,and governance suggestions for different regions are put forward The main conclusions of this paper are as follows:(1)From 2000 to 2020,the spatial distribution of ecological vulnerability in the Hehuang area has obvious geographical differences.Roughly present a cross-distribution between east–west and north–south,that is,micro–vulnerable and mildly vulnerable areas are mainly distributed in the northwest and southeast regions of the study area,and moderate vulnerable and heavy vulnerable areas are mainly distributed on the east and west sides of the study area.In terms of area proportion,the ecological vulnerability of Hehuang area is mainly light and medium,and the area proportion in each year is 62.1%,61.3%,73%,75.7% and 74% respectively.The second is the severely vulnerable area and the slightly vulnerable area.The area proportions of each year are 35.6%,34.3%,26.2%,23.9% and 25.6% respectively.The area of extremely vulnerable areas is the smallest.(2)High and low value aggregation patterns of ecological vulnerability in the Hehuang region cross coexist.The results of spatiotemporal scanning shows that the ecological vulnerability of the Hehuang region in 2000–2020 shows obvious temporal aggregation and local spatial aggregation characteristics.The main manifestations are high–value high clustering and low–value high clustering,and both are mainly distributed in Gansu Province.High–value clusters are mainly distributed in Lanzhou City,Baiyin City under the jurisdiction of some counties(districts).Only some regions of Gonghe County in Qinghai Province have high value aggregation,and "low–low" clusters are mainly distributed in Linxia Hui Autonomous Prefecture,Gannan Tibetan Autonomous Prefecture,and Dingxi City under the jurisdiction of some counties(districts).(3)The interannual variation of ecological vulnerability in the Hehuang area has significant differences.From 2000–2005,2005–2010,and 2015–2020,ecological vulnerability as a whole mainly showed a decline in characteristics.The area of heavily vulnerable and extremely vulnerable areas accounted for a significant reduction,while the areas of lightly vulnerable and moderately vulnerable areas have increased to varying degrees.From 2010 to 2015,the ecological vulnerability did not change significantly and decreased slightly.The overall transformation pattern from 2000 to2020 shows that the ecological vulnerability of nearly half of the land in the study area remains stable and unchanged,accounting for 42.79% of the total area of the study area.The ecological vulnerability of more than half of the land has been reduced,accounting for 53.36% of the total area of the study area.(4)The impact of each assessment index on ecological vulnerability is different,and the vegetation coverage has the largest impact.By analyzing the explanatory power of each evaluation index relative to ecological vulnerability through geographic probes,the study found that the factor with the greatest influence on ecological vulnerability was vegetation cover,indicating that the amount of vegetation in the study area plays a key role in whether ecology vulnerable or not.In addition,factors such as desertification index,net primary productivity of vegetation,drought index,habitat quality index,and elevation also have a large degree of influence on ecological vulnerability.(5)Different ecological fragility subareas in Hehuang region have their own unique fragility change mode.By summarizing the overall change pattern of ecological vulnerability from 2000 to 2020,Hehuang region can be divided into five ecological vulnerability zones: Ecological core protection area,ecological comprehensive management area,ecological restoration concern area,ecological priority management area,and ecological key monitoring area.Each ecological zone has distinct characteristics of ecological vulnerability change.For different ecological zonings,developing a reasonable ecological management plan can effectively alleviate the ecological vulnerability of the Hehuang area. |
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