Abstract:
To explore the ecosystem stability and its influencing factors in the Yangtze River Basin, the Enhanced Vegetation Index (EVI) data of the Yangtze River Basin from 2001 to 2020 were obtained, and the Yangtze River Basin was divided into more than 1.78 million 1 km * 1 km grids. The EVI slope of each grid from 2001-2010, 2001-2011, 2001-2012 to 2001-2020 was fitted, and the number of grids with positive or negative slope was counted respectively. The exponential decay function was used to fit the attenuation of the positive and negative trends, and the ecological resilience of the Yangtze River basin was evaluated. Spearman correlation coefficient was used to analyze the effects of rainfall, topography (altitude, slope) and vegetation cover on ecosystem resilience. The results show that the average vegetation cover index (EVI) in the Yangtze River basin has increased by 7.76% from 2001 to 2020, and the vegetation cover was gradually getting better. The decay time difference between the grid with positive trend and the grid with negative trend is 29.48 years, the overall ecological environment is positive succession, and the overall ecosystem resilience is average. The ecological resilience of the Yangtze River Basin is characterized by high in the middle region, low in the source region and the lower reaches, and poor in the estuary of the Yangtze River. The ecological resilience of the Yangtze River Basin was not significantly affected by the topography (elevation, slope) and rainfall, but vegetation cover had a certain effect on ecosystem resilience which increased with vegetation index. The results show that the vegetation coverage in the Yangtze River Basin is on the rise, and the spatial difference of ecosystem resilience is obvious.