TY - JOUR

T1 - Trends in River Total Suspended Sediments Driven by Dams and Soil Erosion

T2 - A Comparison Between the Yangtze and Mekong Rivers

AU - Guan, Qi

AU - Feng, Lian

AU - Tang, Jing

AU - Park, Edward

AU - Ali, Tarig A.

AU - Zheng, Yi

PY - 2022

Y1 - 2022

N2 - Global river systems are experiencing rapid changes in sediment transport under growing anthropogenic and climatic stresses. However, the response of sediment discharge to the coupled influence of anthropogenic and natural factors and the associated impacts on the fluvial geomorphology in the Yangtze and Mekong rivers are not comprehensively assessed. Here, we recalibrated a seamless retrieval algorithm of the total suspended sediment (TSS) concentrations using in situ data and concurrent satellite data sets to analyze spatiotemporal patterns of the TSS concentrations in the lower Yangtze and Mekong rivers. Combined with soil erosion rates estimated by the Revised Universal Soil Loss Equation for the past 20 years, we examined the contributions of different factors to TSS trends. The results show that TSS concentrations in the Yangtze River decreased from 0.47 g L-1 in 2000 to 0.23 g L-1 in 2018 due to the construction of the Three Gorges Dam (TGD), especially in the Jingjiang reach, with a declining magnitude of 0.3 g L-1 (similar to 56%) since the TGD began operating. The Mekong River experienced increasing TSS concentration trends upstream and decreasing trends downstream from 2000 to 2018, possibly attributed to increased upstream soil erosion and decreased downstream water discharge. Declining TSS concentrations in both rivers have driven varying degrees of river channel erosion over the past two decades. This study investigated long-term changes in the TSS concentrations and soil erosion in the Yangtze and Mekong rivers, and the results provide baseline information for the sustainable development of river sediment delivery.

AB - Global river systems are experiencing rapid changes in sediment transport under growing anthropogenic and climatic stresses. However, the response of sediment discharge to the coupled influence of anthropogenic and natural factors and the associated impacts on the fluvial geomorphology in the Yangtze and Mekong rivers are not comprehensively assessed. Here, we recalibrated a seamless retrieval algorithm of the total suspended sediment (TSS) concentrations using in situ data and concurrent satellite data sets to analyze spatiotemporal patterns of the TSS concentrations in the lower Yangtze and Mekong rivers. Combined with soil erosion rates estimated by the Revised Universal Soil Loss Equation for the past 20 years, we examined the contributions of different factors to TSS trends. The results show that TSS concentrations in the Yangtze River decreased from 0.47 g L-1 in 2000 to 0.23 g L-1 in 2018 due to the construction of the Three Gorges Dam (TGD), especially in the Jingjiang reach, with a declining magnitude of 0.3 g L-1 (similar to 56%) since the TGD began operating. The Mekong River experienced increasing TSS concentration trends upstream and decreasing trends downstream from 2000 to 2018, possibly attributed to increased upstream soil erosion and decreased downstream water discharge. Declining TSS concentrations in both rivers have driven varying degrees of river channel erosion over the past two decades. This study investigated long-term changes in the TSS concentrations and soil erosion in the Yangtze and Mekong rivers, and the results provide baseline information for the sustainable development of river sediment delivery.

KW - total suspended sediment

KW - dam

KW - MODIS

KW - Yangtze

KW - Mekong

KW - soil erosion

KW - 3 GORGES DAM

KW - LAND-USE

KW - COASTAL WATERS

KW - BASIN

KW - CHANGJIANG

KW - DISCHARGE

KW - IMPACTS

KW - SEA

KW - VARIABILITY

KW - HYDROPOWER

U2 - 10.1029/2022WR031979

DO - 10.1029/2022WR031979

M3 - Journal article

VL - 58

JO - Water Resources Research

JF - Water Resources Research

SN - 0043-1397

IS - 10

M1 - e2022WR031979

ER -