Causes of Variations in Sediment Yield in the Jinghe River Basin, China

Jinliang Zhang,Shitao Wei,Yizi Shang,Liang Tong,Jinyong Liu,Jian Fu

doi:10.1038/s41598-020-74980-3

Abstract

The Jinghe River remains the major sediment source of the Yellow River in China; however, sediment discharge in the Jinghe River has reduced significantly since the 1950s. The objective of this study is to identify the causes of sediment yield variations in the Jinghe River Basin based on soil and water conservation methods and rainfall analyses. The results revealed that soil and water conservation projects were responsible for half of the total sediment reduction; sediment retention due to reservoirs and water diversion projects was responsible for 1.3% of the total reduction. Moreover, the Jinghe River Basin has negligible opportunity to improve its vegetation cover (currently 55% of the basin is covered with lawns and trees), and silt-arrester dams play a smaller role in reducing sediment significantly before they are entirely full. Therefore, new large-scale sediment trapping projects must be implemented across the Jinghe River Basin, where heavy rainfall events are likely to substantially increase in the future, leading to higher sediment discharge.

Highlights

Climate, underlying surfaces, runoff, and sediment discharge constitute the hydrological system in a river basin
Since the 1950s, the Yellow River Conservancy Commission has promoted various soil and water conservation works in the Jinghe River Basin, including modifying terraced fields, planting trees and grass, building dams, returning farmlands to forests, and creating enclosures
Since 2000, the average annual sediment discharge in the river has decreased by ~ 153,000,000 t (61.2%) to ~ 97,000,000 t from that during the period from 1956–2000, which suggests that current conservation practices in the basin have been successful, such that studies have forecasted a sustainable reduction in sediment discharge into the river

Summary

Introduction

Climate, underlying surfaces, runoff, and sediment discharge constitute the hydrological system in a river basin. Changes to the surface of the earth by human activity have altered the runoff and sediment discharge processes in river basins[4,5]. Runoff and sediment discharge have a complex response relationship with the climate and the underlying surfaces, which is highly nonlinear and uncertain This renders such processes of change difficult to understand and control. Li et al.[23] used measurement data from 1960–2012 at the Maduwang hydrometric station on the Bahe River to determine the relationship between rainfall and runoff/ sediment discharge in the basin. Recent studies have further shown that changes in the underlying surface conditions, associated with engineering projects implemented by humans, are the dominant contributor to runoff and sediment reduction in the Yellow River[27,28,29,30]

Objectives

Methods

Results

Discussion

Conclusion