Driving forces of nature and human activities on water and sediment changes in the middle reaches of the Yellow River in the past 100 years

The temporal and spatial variation of ecological land use and its current distribution were studied to provide reference for the protection of original ecological land and ecological environment in the Yellow River Delta. Using RS colour synthesis, supervised classification, unsupervised classification, vegetation index and other methods to monitor the impact of human activities on the original ecological land in the past 30 years; using GIS technology to analyse the statistical data and construct the model of original ecological land area index to study the ecological land distribution status. The results show that the boundary of original ecological land in the Yellow River Delta had been pushed toward the coastline at an average speed of 0.8km per year due to human activities. In the past 20 years, a large amount of original ecological land gradually transformed into artificial ecological land. In view of the evolution and status of ecological land in the Yellow River Delta, related local departments should adopt differentiated and focused protection measures to protect the ecological land of the Yellow River Delta.

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Dynamic landscapes and the driving forces in the Yellow River Delta wetland region in the past four decades

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.147644 ◽

2021 ◽

pp. 147644

Author(s):

Xiaojing Zhang ◽

Guoqiang Wang ◽

Baolin Xue ◽

Mengxue Zhang ◽

Zhongxin Tan

Keyword(s):

Driving Forces ◽

Yellow River ◽

Yellow River Delta ◽

River Delta ◽

The Yellow River ◽

The Yellow River Delta ◽

The Past ◽

Dynamic Landscapes ◽

Yellow River Delta Wetland

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Organic carbon transport and impacts of human activities in the Yellow River

Biogeosciences Discussions ◽

10.5194/bgd-9-14365-2012 ◽

2012 ◽

Vol 9 (10) ◽

pp. 14365-14405 ◽

Cited By ~ 2

Author(s):

L. J. Zhang ◽

L. Wang ◽

W.-J. Cai ◽

D. M. Liu ◽

Z. G. Yu

Keyword(s):

Organic Carbon ◽

Loess Plateau ◽

Human Activities ◽

Yellow River ◽

The Yellow River ◽

The Loess Plateau ◽

Water And Sediment ◽

Poc Flux ◽

Reservoir Construction ◽

Carbon Transport

Abstract. Based on four field investigations during 2003 and 2009 along the Yellow River mainstream, we examined the distributions, seasonal variations and transport features of organic carbon, with a focus on the impacts of human activities (reservoir construction and regulation scheme). The results showed that organic carbon transport processes in the Yellow River were different from other major rivers. Particulate organic carbon (POC) dominated in the Yellow River and it mainly originated from the Loess Plateau. POC levels in suspended sediment (POC %) ranged between 0.25% and 2.20% and more than 80% of POC concentrated in the particles with grain size smaller than 16 μm. On time scale, dissolved organic carbon (DOC) correlated negatively with discharges, indicating the influence of dilution effect. Along the river on spatial scales, DOC in the Qinghai-Tibet Plateau was closely related with temperature while DOC in the Loess Plateau showed the concentration effect, due to the abundant human input and the high ratio of evaporation to precipitation. Organic carbon in the Yellow River was very refractory and about 90% of POC and 70% of DOC cannot be degraded. Due to the high turbidity, the Yellow River suffers more impacts from the reservoirs in the transport of total suspended solids (TSS) and organic carbon. Ratios of DOC/POC ranged between 2.0 and 12 in the reservoirs and organic carbon was mainly in the dissolved from. POC deposited in the reservoirs of the Yellow River achieved 0.0033 Gt a−1, about 8 times its annual POC flux discharged to the ocean. During the 2008 Water and Sediment Regulation (WSR) period, DOC and POC fluxes was as high as 1.1 × 1010 g and 2.2 × 1011 g respectively, accounting for 35% of annual DOC flux and 56% of the annual POC flux to the ocean. Discharges and material fluxes to the ocean decline sharply due to the reservoir construction while large amounts of water and sediment are transported to the ocean in such a~short WSR period. These two human disturbances totally altered the processes of substance transport in the Yellow River, and may change the water chemical characteristics in the coastal zones.

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The variation and attribution analysis of the runoff and sediment in the lower reach of the Yellow River during the past 60 years

Water Science & Technology Water Supply ◽

10.2166/ws.2021.085 ◽

2021 ◽

Author(s):

Hongxiang Wang ◽

Jinghang Liu ◽

Wenxian Guo

Keyword(s):

Human Activities ◽

Sediment Load ◽

Yellow River ◽

Annual Runoff ◽

Ratio Method ◽

The Yellow River ◽

Lower Reach ◽

Lower Yellow River ◽

The Lower Yellow River ◽

Water And Sediment

Abstract The water and sediment regimes of the Yellow River are the basis of decision-making of major projects of the Yellow River. Based on the water and sediment data at the Huayuankou station, Gaocun station, Aishan station, Lijin station in the lower reach of the Yellow River, the Mann-Kendall test, the T-test for differences, wavelet analysis, slope change ratio method and the double cumulative curve method were applied to analyze the runoff and sediment regimes alteration. The results show that the water and sediment of the lower Yellow River have a significant downward trend, and the annual sediment decreases significantly compared with the annual runoff. The annual runoff and sediment of the four hydrological stations changed around the 1980 and 1990s, respectively. The water and sediment of hydrological stations have periodic variations on multiple time scales, but the variation scales are different. Precipitation, human activities and other factors lead to the decrease trend of water and sediment in the lower Yellow River, and their contribution rates to the change of water and sediment are also different. Precipitation contributed 0.15%–8.71% and 0.06%–22.32% to the reduction of runoff and sediment load at hydrological stations, while human activities contributed 91.29%–99.85% and 77.68%–102.21% to the reduction of runoff and sediment load, respectively. Human activity is the main factor of runoff and sediment reduction.

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