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Assessing and controlling the risk of cyanobacterial blooms
Published in Ingrid Chorus, Martin Welker, Toxic Cyanobacteria in Water, 2021
Ingrid Chorus, Matthias Zessner
Where erosion occurs, soil particles will be carried towards the waterbody, thus transporting the P adsorbed to them. There is consensus that streambank erosion is a highly relevant pathway for phosphorus loading: Fox et al. (2016) review case studies of P loads from streambanks and conclude that 7–92% of the total P loads could be accounted for by streambank and gully erosion. Peacher et al. (2018) also review streambank erosion as a major source of nutrient loads transported with sediment and report own results for P loss rates with soil eroded from riverbanks in the range of 38–49 g/m and year for the riverbanks of two streams in Missouri; these loads amounted to 67% of the P transported in these creeks. Although there are examples of situations in which plant root growth contributes to riverbank erosion, in general an intact cover of vegetation (“riparian buffer strip”) stabilises the riverbank and can serve to intercept soil in surface run-off (see discussion in Fox et al., 2016).
Proposing BEHI-NBS method for the estimation of river bank erosion on a river in Nepal
Published in Silke Wieprecht, Stefan Haun, Karolin Weber, Markus Noack, Kristina Terheiden, River Sedimentation, 2016
River bank erosion or channel migration is a natural and geomorphic process of change in river resulted by adjustment of channel size and shape. Such changes are quite variable in space, depending in part upon position within the basin, and influenced by local variation in geology, soil, bank characteristics, vegetation, hydraulics, and other factors that influence vulnerability such as various types of land use (Aher et al. 2012). River changes in response to variation of variables like discharge and sediment supply (Mossa & Coley 2004). Rivers always tend to remain in the dynamic equilibrium state and to maintain this state, river balances its flow and sediment transport. In a free-flowing river system this equilibrium is always maintained by process of erosion and deposition (CRJC 1996). Bank erosion are special features of meandering river, where river channel migration takes place by erosion of the cut bank and deposition of eroded materials on point bar forming point bar deposit (Briaud et al. 2007, Das et al. 2014a). When river reaches lower reach, most of its erosive force concentrates to cut laterally hence, forming the meandering pattern (Das et al. 2014a). The migrating stream has tendency to widen the channel and erode the bank by undercutting its toe material and caving the bank (Baishya 2013). The fertile upland soil is then washed away by flow of the channel and deposited in the floodplain. These floodplain provides better yield and because of this benefit, these land are over cultivated, trees are cut down and cultivated field are poorly managed (Kaunda & Chapotoka 2003). Hence, destruction of flood plain and a reduction in the resource value of the river is associated with serious bank erosion (Thorne 1999).
Flow characteristics around pile-group groynes with different arrangements of piles
Published in Wim Uijttewaal, Mário J. Franca, Daniel Valero, Victor Chavarrias, Clàudia Ylla Arbós, Ralph Schielen, Alessandra Crosato, River Flow 2020, 2020
Riverbank erosion is a natural process that can cause problems to adjacent structures, land, or infrastructure. Riverbank erosion also affects the meandering tendency of streams (Przedwojski 1995). One of the effective methods of protecting a bank is the construction of a series of groynes or spur-dikes. A groyne is a hydraulic structure that extends from a bank into the river to control the flow direction and velocity.
Prediction of fluvial erosion rate in Jamuna River, Bangladesh
Published in International Journal of River Basin Management, 2022
Md. Shahidul Islam, Md. Abdul Matin
Two main mechanisms involved in riverbank erosion are fluvial erosion and mass failure (Couper & Maddock, 2001; Lawler et al., 1999; Zong et al., 2017). The most important mechanism controlling bank erosion is fluvial erosion (Kimiaghalam et al., 2015; Rinaldi & Nardi, 2013). Fluvial erosion is the direct removal of soil particles from the river bank by the erosive action of flowing water, while the collapse of the riverbank due to an unstable slope is known as mass failure (Lawler, 1995). Mass failures are usually initiated at the toe driven by hydrodynamic forces depending on the geotechnical load on the bank. Rinaldi and Darby (2007) reported that the long-term bank erosion rate is controlled by fluvial erosion near the bank toe. Therefore, the erosion process due to fluvial action needs to be modelled correctly before assessing the erosion caused by mass failure.
Morphological study of Upper Tapi river using remote sensing and GIS techniques
Published in ISH Journal of Hydraulic Engineering, 2019
S. R. Resmi, P. L. Patel, P. V. Timbadiya
The rivers are invariably posed to severe threats due to excessive erosion and deposition owing to the lateral migration of their either banks. The river tries to adjust its course to account for the lateral and vertical instability along its course (Rinaldi 2003). One of the major causes of such instability is the imbalance between sediment carrying capacity of the river and inflow of sediment, into the river (Garde and Raju 2000). While the rivers try to attain their equilibrium states, the external forces such as river regulations and enhanced land-use pressures degrade their flood plains (Hazarika et al. 2015). River bank erosion is an endemic and recurrent natural hazard, whose prolonged effects can cause serious damages to flood-plain dwellers, agricultural lands along the flood-plain, riparian vegetation, natural habitats, engineering structures like dams, bridges and embankments and grave consequences on the ground water table (Debnath et al. 2017). Identification of vulnerable locations/reaches along the river course in plan is extremely important to document the erosion hazard and to implement relevant management and stabilization measures. Leading studies undertaken in the past to identify the spatio-temporal pattern of the river planform and their bankline migration, with the aid of GIS and Remote Sensing tools, which will be useful to the reader for future reference are Das et al. (2012), Sarkar et al. (2012), Thakur et al. (2012), Florsheim et al. (2008), Heo et al. (2009) and Yang et al. (1981).