SPATIAL-TEMPORAL EVOLUTION OF ECOLOGICAL VULNERABILITY IN DADU RIVER BASIN, CHINA

This paper selected 14 evaluation indices using SRP model and constructed the Dadu River basin ecological vulnerability assessment system by AHP.(1) The classification of ecological vulnerability from high to low is extremely vulnerable (EVI 0.50), severely vulnerable (0.46 EVI < 0.50), moderate vulnerable (0.42 EVI < 0.46), mild vulnerable (0.38 EVI < 0.42), and slightly vulnerable (EVI < 0.38).( 2) The northern and central parts of the basin are mostly extremely and severely vulnerable areas, and the ecological vulnerability index decreases with altitude.(3) In terms of spatio-temporal transformation, the area of slight vulnerability decreased by 2,033 km, which accounted for 2.74% of the total watershed area.Extremely vulnerable areas increased by 2,649 km, or 3.41%.( 4) From the perspective of factor detection, the factors with the strongest explanatory power for ecological vulnerability are GDP, population, annual sunshine, soil viscosity and annual average relative humidity.(5) From the perspective of origin, the extremely and severely vulnerable areas are mostly located in the plateau and mountainous regions, and climate and topography are the important reasons for their ecological vulnerability.Human economic activities are closely related to the degree of vulnerability.