长江流域植被变化影响因素与水沙关系研究OA

[Objective]This study systematically investigates the spatiotemporal characteristics of vegetation change in the Yangtze River Basin,its main driving factors,and the coupling relationship with water-sediment processes,providing a scientific basis for ecological protection and resource management in the river basin.[Methods]Based on normalized difference vegetation index(NDVI),meteorological data,and water-sediment data in the Yangtze River Basin from 2001 to 2020,trend analysis,correlation analysis,and residual analysis were applied to quantitatively assess the impact of climatic factors and human activities on vegetation evolution.Additionally,the relationships between NDVI,annual sediment load,and annual runoff were analyzed.[Results]The NDVI in the Yangtze River Basin showed an overall fluctuating upward trend,with an average annual growth rate of 0.001 7/a.Among them,the middle and upper reaches demonstrated significant NDVI increases(0.001 7/a and 0.001 9/a,respectively),while a notable decline(-0.000 9/a)was observed in the lower reaches.Temperature had the most significant promoting effect on vegetation growth,while the impact of precipitation and solar radiation exhibited distinct regional differences.Ecological projects such as Grain-for-Green Program significantly improved vegetation cover in the upper and middle reaches,while urban expansion led to vegetation degradation in the lower reaches.Vegetation recovery substantially reduced annual sediment load and increased runoff in the upper and middle reaches,while water-sediment processes in the lower reaches were mainly regulated by reservoirs.[Conclusion]Vegetation changes in the Yangtze River Basin show significant spatiotemporal heterogeneity and are jointly driven by climate change and human activities.Ecological projects have effectively enhanced ecological quality and ecosystem regulatory functions through water-sediment process regulation,which is crucial for sustainable development of the river basin.