Impacts of Climate Change and Human Activities on Water-Sediment Variation in Ganjiang River

YANG Xia

doi:10.3969/j.issn.1004-7328.2026.07.001

Abstract：Water-sediment variation is an important factor affecting river ecological health.In recent years,under the combined effects of climate change and human activities,the water-sediment characteristics of the Ganjiang River have changed significantly.To investigate the water-sediment variation characteristics and their causes in the Ganjiang River,this paper is based on data from 40 meteorological stations in the Ganjiang River basin and Ganjiang River hydrological data from 1960 to 2018,sorting out water-sediment variation characteristics in different periods and quantitatively analyzing the attribution of water-sediment variation.The results show that precipitation and runoff in the Ganjiang River basin both show a non-significant increasing trend,while sediment transport shows a significant decreasing trend;the difference in precipitation-runoff relationship over time is significantly smaller than that in precipitation-sediment transport relationship,especially after the construction of the Wan′an Reservoir,where the difference becomes even more pronounced.Sediment reduction by the Wan′an Reservoir mainly occurs from March to October,of which the sediment reduction from March to June accounts for 77.3%of the annual total;large reservoirs on the main stream of the Ganjiang River have significantly stronger sediment reduction capacity than those on tributaries.Overall,climate change is the main cause of the increase in runoff,while human activities play a dominant role in runoff variation and sediment transport reduction.The research results can provide reference for water-sediment regulation,reservoir operation management,and river ecological protection in the Ganjiang River basin.