Powhatan, Louisiana: A Case Study in River Morphology

1999 ◽  
Vol 14 (2) ◽  
pp. 70-72
Author(s):  
Paul R. Baumann
Keyword(s):  
River Morphology

Effects of an extreme flood on river morphology (case study: Karoon River, Iran)

Geomorphology ◽  
2018 ◽  
Vol 304 ◽  
pp. 30-39 ◽  
Author(s):  
Saleh Yousefi ◽  
Somayeh Mirzaee ◽  
Saskia Keesstra ◽  
Nicola Surian ◽  
Hamid Reza Pourghasemi ◽  
...  
Keyword(s):  
River Morphology ◽  
Karoon River ◽  
Extreme Flood

scholarly journals Impacts of the Degraded Alpine Swamp Meadow on Tensile Strength of Riverbank: A Case Study of the Upper Yellow River

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2348
Author(s):  
Haili Zhu ◽  
Peng Gao ◽  
Zhiwei Li ◽  
Jiangtao Fu ◽  
Guorong Li ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Alpine Meadow ◽  
Yellow River ◽  
River Morphology ◽  
Root Number ◽  
Root Structure ◽  
Meandering Rivers ◽  
Upper Yellow River

In the meandering riverbank of the Upper Yellow River (UYR), the native alpine swamp meadow (AS) has continuously degenerated into an alpine meadow (AM) due to climate change and intensified grazing. Its implication on river morphology is still not well known. This study examined this effect by in situ measurings of (1) physical properties of roots and their distribution in the soil-root mixture of the upper bank layer, and (2) the tensile strength in terms of excavating tests for triggering cantilever collapses of AS and AM riverbanks. The results showed that the root number in AS was significantly greater than that in AM, though the root distribution in both was similar. Also, the average tensile strength of individual roots in AS was 31,310 kPa, while that in AM was only 16,155 kPa. For the soil-root mixture, it decreased from 67.39 to 21.96 kPa. The weakened mechanical property was mainly ascribed to the lessened root number and the simpler root structure in the soil-root mixture of AM that reduces its ability to resist the external force. These findings confirmed that healthy AS can enhance bank stability and delay the development of tensile cracks in the riverbank of the meandering rivers in the UYR.

scholarly journals The Influence of Channel Morphological Changes on Environmental Flow Requirements in Urban Rivers

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1800 ◽  
Author(s):  
Liu Zhang ◽  
Buxian Yuan ◽  
Xinan Yin ◽  
Yanwei Zhao
Keyword(s):  
Flood Control ◽  
Environmental Flows ◽  
Morphological Changes ◽  
Environmental Flow ◽  
Channel Morphology ◽  
Primary Factor ◽  
River Morphology ◽  
Hydrological Connectivity ◽  
Urban Rivers

Previous research on environmental flows (e-flows) of urban rivers usually assumes that the channel morphology is fixed. However, due to the trapping of sediments by weirs, the channel morphology will undergo significant changes. In this research, the influence of channel morphological changes on e-flow requirements is explored in urban rivers. The hydrological connectivity is considered as a primary factor in e-flows, and three hydrological connectivity scenarios (i.e., high, medium, and low) are explored. The Shiwuli River is adopted as the case study. The results show that e-flows are significantly influenced by changes in river morphology. With an increase in siltation depth, the e-flow requirements will decrease. The sensitivity of e-flows to siltation varies among different river segments, especially in those with low weir heights. In addition, the change ratios of e-flows are different under different hydrological connectivity scenarios. Although siltation is beneficial to the satisfaction degree of e-flow supply, it also leads to a decrease in the flood control ability of rivers. The balance between e-flow and flood reduction is also discussed, and river segments are identified that should be the priority when adopting dredging measures.

scholarly journals Effects of merapi eruption on environmental and social conditions: case study in Pabelan River, Indonesia

2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Jazaul Ikhsan ◽  
Indrasweri NK
Keyword(s):  
Debris Flows ◽  
Negative Impact ◽  
Positive Impact ◽  
Mining Activity ◽  
Social Conditions ◽  
River Morphology ◽  
Surface Material ◽  
Sand Mining ◽  
The Social

Debris flows triggered by Merapi eruption in 2010 have impacts on the environment and social condition along the rivers on the volcano, especially in Pabelan River. Material resulted from debris flows could change on morphology and porosity of riverbed surface material, as well as the capacity of sediment. Therefore, it is important to study the influence of Merapi eruption in 2010 on environmental and social conditions in Pabelan River. To determine the river morphology was used Ronsgen method. To calculate porosity of riverbed surface material was used the equation was proposed by Sulaiman. Einstein equation was used to calculate sediment transport. To investigate the social conditions, damage land and sand mining activity were used as parameters. The result has shown that morphology types at confluence Progo-Pabelan Rivers, Srowol Bridge, and Pabelan Bridge 1 were D5b, D5b and E5, respectively. Sedimentation has occurred in the segment between the confluence of Progo-Pabelan Rivers and Srowol Bridge. Erosion has taken place in the segment between Srowol Bridge and Pabelan Bridge 1. The riverbank collapses took place along the river and it gave a negative impact on social conditions. The sand mining activity was intensive, and the activity has a positive impact on the economical inhabitants.

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