Impact of monsoonal climatic change on Holocene overbank flooding along Sushui River, middle reach of the Yellow River, China

Floodplain wetlands are of great importance in the entire river and floodplain ecosystems. Understanding the hydrological processes of floodplain wetlands is fundamental to study the changes in wetlands caused by climate change and human activities. In this study, floodplain wetlands along the middle reach of the Yellow River were selected as a study area. The hydrological processes and the interactions between the river and the underlying aquifer were investigated by combining remote sensing, hydraulic monitoring, and numerical modeling. Wetland areas from 2014 to 2019 were extracted from Landsat 8 remote sensing images, and their correlation with the river runoff was analyzed. The results indicate that the river flow had a limited impact on the wetland size and so did groundwater levels, due to the strong reliance of wetland vegetation on water levels. Based on hydrological and hydrogeological conditions, a surface water–groundwater coupled numerical model was established. The comparison and correlation analysis between the monitored groundwater head and the simulated river stage also show that river flow did not play a first-order role in controlling the groundwater levels of wetlands in the study area. The simulation results also suggest that it is the regional groundwater flow that mainly sustains shallow groundwater of floodplain wetlands in the study area. The floodplain wetland of the study area was dynamic zones between the regional groundwater and river, the contrasting pattern of hydrological regimes on both banks of the Yellow River was due to a combination of regional groundwater flow and topography.

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HELD SURVEY OF SEDIMENTS IN THE MIDDLE REACH OF THE YELLOW RIVER AND EXPERIMENTS OF HYPERCONCENTRATED FLOW IN AN OPEN CHANNEL

PROCEEDINGS OF HYDRAULIC ENGINEERING ◽

10.2208/prohe.48.943 ◽

2004 ◽

Vol 48 ◽

pp. 943-948

Author(s):

Haruyuki HASHIMOTO ◽

Hiroki TAKAOKA ◽

Sinya IKEMATSU ◽

Byungdug JUN ◽

Takahito UENO

Keyword(s):

Open Channel ◽

Yellow River ◽

The Yellow River ◽

Middle Reach ◽

Hyperconcentrated Flow

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Effects of land use/land cover and climatic change on the ecosystem of North Ningxia, China

Arabian Journal of Geosciences ◽

10.1007/s12517-020-06047-6 ◽

2020 ◽

Vol 13 (20) ◽

Author(s):

Hazem T. Abd El-Hamid ◽

Wei Caiyong ◽

Mohammed A. Hafiz ◽

Elhadi K. Mustafa

Keyword(s):

Land Use ◽

Land Cover ◽

Climatic Change ◽

Industrial Development ◽

Environmental Changes ◽

Yellow River ◽

The Yellow River ◽

Land Use Land Cover ◽

Effective Strategies ◽

Total Percentage

AbstractLand use/land cover change (LUCC) and climate changes are responsible for degradation of any ecosystem in arid and semi-arid regions. Studying the ecological variations is particularly essential for any type of sustainable development, in which LUCC considers as one of the chief inputs. The main objective is to evaluate the impacts of LUCC and climatic changes on the Ecosystem Vulnerability (ESV) using remote sensing and some statistical models around the Yellow River, Ningxia, China. Eleven classes of LUCC were identified during 1995 and 2019: village land, bare land, grassland, industrial land, irrigated land, swamp land, tidal flat, transportation land, urban land, water bodies, and water channels. Grassland may be decreased annually with percentage − 5.873% due to some human activities and environmental changes in climate from one season to another. About 24.23 km2 and 24.86 km2 was converted from grassland to industrial lands and irrigated lands, respectively. ESV has been calculated using LULC, DEM, slope, soil, and geology. About 45% and 60% of 1995 and 2019, respectively, undergone moderate vulnerability. The annual rate of ESVI decreased in low and reasonable but it was increased in moderate, high, and extreme showing – 4.166% as a total percentage of annual vulnerability. High vulnerability area needs proper management. Majority of vegetation area is located in zone under the moderate vulnerability zone; in contrast, grasslands were subjected to high vulnerability. Areas around the Yellow River were subjected to drought and flooding due to climatic change affecting negatively on the production of crops. Also, the desert lands of the study area have been turned to agriculture according to statistical model. Population growth, industrial development, and governmental policies for ecosystem protection were responsible for major changes. This study is more beneficial for decision-making in eco-environmental protecting and planning. Results of this study could help planners in formulating effective strategies for better management of ecosystem.

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