scholarly journals Changes in floodplain inundation under nonstationary hydrology for an adjustable, alluvial river channel

2017 ◽  
Vol 53 (5) ◽  
pp. 3811-3834 ◽  
Author(s):  
B. C. Call ◽  
P. Belmont ◽  
J. C. Schmidt ◽  
P. R. Wilcock
Keyword(s):  
River Channel ◽  
Alluvial River ◽  
Floodplain Inundation

Reservoir effects on downstream river channel migration

2000 ◽  
Vol 27 (1) ◽  
pp. 54-66 ◽  
Author(s):  
F. DOUGLAS SHIELDS JR ◽  
ANDREW SIMON ◽  
LYLE J. STEFFEN
Keyword(s):  
Flood Control ◽  
Habitat Type ◽  
River Channel ◽  
Aerial Photographs ◽  
Lateral Migration ◽  
Widespread Application ◽  
Ecosystem Integrity ◽  
Migration Rates ◽  
Alluvial River ◽  
River Floodplains

Human occupation and development of alluvial river floodplains are adversely affected by river channel lateral migration, which may range as high as several hundred metres per year. Reservoirs that reduce the frequency and duration of high flows typically reduce lateral migration rates by factors of 3 to 6. The ecology of riverine corridors is dependent upon the processes of erosion and sedimentation, which lead to lateral migration. Multiple-objective use of floodplains adjacent to active rivers therefore requires tools for assessing the probability and magnitude of channel movements. Existing approaches for predicting river channel movement may be classified as empirical or mechanistic, and are inadequate for widespread application. The Missouri River downstream from Fort Peck Dam in Montana, a major alluvial river with flow highly perturbed by regulation, was selected for case study. Maps and aerial photographs were available before and after dam construction. This imagery was analysed by digitizing channel centrelines at successive coverages under pre-dam and post-dam conditions, and mean migration rates were computed by bend and by reach. The mean rate of channel centreline migration fell from 6.6 m yr-1 to 1.8 m yr-1 after impoundment. Bend-mean channel activity rates were only weakly correlated with variables describing channel form and geometry. Results indicate that flow regulation for flood control and hydropower production typical of the study reach had profound effects on river corridor dynamism, with implications for habitat type distribution and ecosystem integrity.

scholarly journals The importance of threshold in alluvial river channel geometry and dynamics

2021 ◽  
Author(s):  
Colin Phillips ◽  
Claire Masteller ◽  
Louise Slater ◽  
Kieran Dunne ◽  
Simona Francalanci ◽  
...  
Keyword(s):  
River Channel ◽  
Channel Geometry ◽  
Alluvial River

Carbon and nutrient subsidies to a lowland river following floodplain inundation

2016 ◽  
Vol 67 (9) ◽  
pp. 1302 ◽  
Author(s):  
Daryl L. Nielsen ◽  
Robert A. Cook ◽  
Nathan Ning ◽  
Ben Gawne ◽  
Rochelle Petrie
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
River Channel ◽  
Resource Subsidies ◽  
Lowland Rivers ◽  
Main River ◽  
Main River Channel ◽  
Eastern Australia ◽  
Floodplain Inundation ◽  
Nutrient Subsidies

Despite the perceived importance of floodplain inundation to the functioning of lowland rivers, there is limited understanding of the contribution that floodplains make to the main river channel during floods. In 2010, substantial flooding occurred throughout south-eastern Australia, which provided an opportunity to quantify the export of biological material and nutrients from a floodplain back in to the main river channel. We quantified the amounts of zooplankton, phytoplankton, dissolved organic carbon and nutrients within the main river channel of the River Murray immediately upstream of the Barmah–Millewa Forest, and at two sites immediately downstream of the forest during two flood events in July and October of 2010. Results demonstrated that although a smaller flood event in July did not contribute substantially to an increase in the measured parameters, a much larger flood in October contributed 0.4 tonnes (t) of phytoplankton; 7t of zooplankton and 300t of dissolved organic carbon. This suggests that small floods will provide minimal resource subsidies back into the main channel after the cessation of flooding. In comparison, larger floods that result in large volumes of floodplain water returning to the river will provide substantial subsidies of terrestrially derived resources.

Interpretation classification of river channel images

2010 ◽  
Vol 30 (11) ◽  
pp. 2995-2997
Author(s):  
Lu-qiang XU ◽  
Jing-xia LIN ◽  
Yun-bing SHI ◽  
Jun QIN
Keyword(s):  
River Channel
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