Variation and Driving Factors of Water Discharge and Sediment Load in Different Regions of the Jinsha River Basin in China in the Past 50 Years

Shang-Wu Liu,Quan-Xi Xu,De-Chun Liu,Miao-Lin Wang,Xiao-Feng Zhang,Jing Yuan

doi:10.3390/w11051109

Shang-Wu Liu, Quan-Xi Xu + Show 4 more

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https://doi.org/10.3390/w11051109

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Journal: Water	Publication Date: May 27, 2019
Citations: 14	License type: CC BY 4.0

Affiliation: Wuhan University, Changjiang Water Resources Commission

Abstract

The Jinsha River is the main source of sediment in the Yangtze River Basin. The variation of water discharge and sediment load not only affects the operation of the cascade reservoirs in the basin but also change the water and sediment conditions into the Three Gorges Reservoir. The Jinsha River Basin is divided into six regions based on the measured data of hydrological stations. Herein, the variation regularity and driving factors of water discharge and sediment load in the Jinsha River Basin are analyzed in the past 50 years using the Mann–Kendall and Rank Sum Test. Results show that the source of water and sediment in the Jinsha River Basin is different, and the abrupt and trend changes of water discharge and sediment load in different regions are evident different. Changes in precipitation, water and soil conservation projects, and the construction of reservoirs are the main driving factors of sediment load variation. The average annual sediment reduction load in the Jinsha River from 1998 to 2015 is approximately 99.57 × 106 t/y, of which the contributions of water discharge change and human activities to sediment load are 18.9% and 81.1%, respectively. The reduction of sediment load in the Jinsha River Basin can result in evident decrease in the sedimentation of cascade reservoirs, erosion of the downstream channel of the river, and considerable reduction of sediment load into the Three Gorges Reservoir.

Highlights

Rivers are major pathways that link continents and oceans and deliver large quantities of land-derived materials to the oceans [1,2].These pathways are highly important to maintain the fluvial geomorphology of rivers, deltas and stabilize the “land-to-sea” ecosystem
Making the summation statistics of ∆SWater and ∆Shuman in above regions based on the results in Table 6, we find the facts that the influence of human activity is still greater than that of water discharge change, generally, in spite of the variation of sediment load differs in different region in above regions
We estimated the contributions of the variation of water discharge and human activities to the variation of sediment load

Summary

Introduction

Rivers are major pathways that link continents and oceans and deliver large quantities of land-derived materials (including fresh water, sediment, elements, and nutrients) to the oceans [1,2]. These pathways are highly important to maintain the fluvial geomorphology of rivers, deltas and stabilize the “land-to-sea” ecosystem. Sediment and water are the most important substances in rivers, and their transportation is vital to maintain the stability of the dynamic geomorphologic processes in rivers, offshore, and deltas Their transport are gradually deteriorating due to global climate change and increased human activities. In the past 60 years, under the background of climate change and the increasingly extensive and intensive human activities, sediment load in many

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