Eco-environment Vulnerability Evolution Of The Seasonal River In Inner Mongolain Reach Of The Yellow River And Its Driving Force Analysis

The increasing global changes and human activities have a huge impact on the ecosystem,resulting in many ecological vulnerability problems.At present,the study of ecological vulnerability has become a research hotspot of global change and sustainable development.Ten tributaries are the main source of sediment increase in the Yellow River Basin in Inner Mongolia and the main source of Sandstorm in Inner Mongolia and North China.The ecological fragility in this area threatens the ecological health of the Inner Mongolia section of the Yellow River Basin,restricts the regional social and economic development,and affects the production and living standards of the local farmers and herdsmen.Only by mastering the spatial and temporal distribution characteristics of regional ecological vulnerability and its occurrence mechanism.and formulating targeted ecological environment protection and restoration measures,can the sustainable utilization of regional natural resources and the sound cycle development of ecological environment be realized.However,at present,the research on the ecological vulnerability of the top ten tributaries is relatively lacking.In this study,the Delphi method was used to select 17 evaluation indexes and construct ten ecological vulnerability evaluation index systems of ten tributaries.With the help of remote sensing and geographic information system,the ecological vulnerability of the study area in 2000-2018 was evaluated comprehensively and quantitatively by using two models of analytic hierarchy process and spatial principal component analysis.This paper analyzes the evolution characteristics of spatial-temporal pattern of ecological vulnerability in the study area from 2000 to 2018 and explores the driving factors of ecological vulnerability in the study area.The main conclusions are as follows:(1)The vulnerability of ecological environment in the study area is generally on the decline,but the overall state is still relatively fragile.In the spatial pattern,the degree of vulnerability gradually increased from north to south.The degree of damage of the ecological environment system in the northern region was relatively light,and the decreasing trend of the development of ecological environment quality in the southern region was more obvious,and the degree of vulnerability was higher.(2)There are also obvious differences in the spatial distribution of the assessment units of ecological environment vulnerability in the study area.The most widely distributed vulnerability grades are mild and moderate,accounting for more than 80%of the total area of the area,mainly distributed in the northern plain of the study area.The proportion of extreme vulnerability is relatively small,which mainly occurs in the middle and lower reaches from the east of the Haoqing River to the west of the hashilachuan river.(3)From 2000 to 2018,the area of moderate and severe vulnerability in the study area continued to decline,while micro and mild vulnerability showed an overall growth trend,and the comprehensive index of ecological environment vulnerability(EVSI)showed a minimum value in 2018,indirectly reflecting that with the passage of time and the increase of people's environmental protection capacity,the implemented projects and measures gradually played a role.(4)Through the combination of spatial principal component analysis and analytic hierarchy process,the first six principal components with high weight contribution rate are extracted.It is found that NDVI,land use type,annual average temperature,annual average precipitation,land reclamation rate,elevation and other factors are the main driving factors leading to the ecological vulnerability of the study area.Based on the study of ecological vulnerability in the ten tributaries areas,the paper analyzes the evaluation results of ecological vulnerability in the ten tributaries areas,and puts forward the countermeasures and measures to improve the ecological environment in the study area,In order to provide scientific basis for the sustainable utilization of local natural resources and the healthy development of ecological environment.