Gradual growth of the central bar deflects the main current against the channel banks causing them to erode Schumm and Khan, A braided pattern once established may be maintained with only slow modifications. Meandering rivers develop sinuous channels and are essentially single-channel systems with no central bar. The amounts of braiding and meandering displayed by the rivers vary greatly from river to river and along the course of particular rivers.
A braided stream can change into a meandering one in a relatively short reach, while individual channels of a braided stream may meander. However, straight channels are not common in nature. Reaches which are straight for distances exceeding ten times the channel width are rare Schumm, We follow the modified scheme of Friend and Sinha to describe the plan form of the channels. This modification allows measurements readily from topographical maps, aerial photographs and satellite images and also has the advantage that the channel length is unlikely to change in a major way with changes of river water level.
This modification is also useful when the rivers show transition between single-channel and braided morphologies. The new definition of sinuosity can be employed to every river no matter it has single or multiple channel or both. In case of multiple channels, mid-channel length of the widest channel in each reach of channel belt is taken into account. The specification of primary channels recognizes that some braiding patterns display a scaling hierarchy of channel sizes Rust, and that only the major ones should be used for this measurement.
The widest channel in a reach should be taken as the major channel. If a reach has only a single channel, with no braids, B will have a value of unity and will thus compare with the measurement of sinuosity P , which will have a minimum value of unity. The most commonly used index of channel shape is width w to depth d ratio even though it is not always the most appropriate. This index gives the gross dimensions of the channel but do not uniquely define cross-sectional shape. Tracing of palaeochannels of Bakulahi river system in Uttar Pradesh, India.
Palaeochannels can be good possible reservoirs of groundwater and are good rechargeable aquifers. Bakulahi is a plain-fed tributary of the Sai River flowing from north-west to south-east direction with about km length and about Bakulahi is a plain-fed tributary of the Sai River flowing from north-west to south-east direction with about km length and about sq. It emanates from interconnected series of tals large- to medium-sized shallow depressions situated in the Raebareli district, Uttar Pradesh, India.
Course of the Bakulahi River is shifted laterally and left many fluvial landforms— palaeochannels, oxbow lakes, meander cutoff, etc. The digitized details from remote sensing data are validated with some field observations.
REstoring rivers FOR effective catchment Management
Different thematic maps are prepared by converting Google Earth feature files. There are about palaeochannels covering about km2 area This is the first scientific attempt to trace palaeocourses of the Bakulahi River. The present paper also answers the question about the origin of the Bakulahi River.
Demarcation of precise basin boundary through manual method by using high-resolution remote sensing data is another contribution of this exercise which is otherwise a difficult task without the availability of high resolution DEM. Shashi shekhar Shukla. The Chao Phraya River flows in the largest river basin of Thailand and represents one of the important agricultural and industrial areas in Southeast Asia.
Anthropogenic impacts on the morphology of the Haora River, Tripura, India
The Ping River is one major upstream branch flowing down slope southwardly, The Ping River is one major upstream branch flowing down slope southwardly, joining the Chao Phraya River in the low-lying central plain and ending its course at the Gulf of Thailand. Surprisingly, the overflow occurs frequently and rapidly at the Lower Ping River where channel slope is high, and in particular area, sand-choked is extensively observed, even in normal rainfall condition.
In contrary, at the downstream part, the erosion of river bank and shoreline around the mouth of Chao Phraya River has been spatially increasing in place where there should be a massive sediment supply to form a delta. Here we use Landsat imageries taken in , , and to analyze geomorphological changes of rivers. Results show that both rivers have undergone the rapid decreasing of water storage capacity and increasing of sand bar areas in river embayment. The total emerged sand bar area in the Lower Ping River increases from to up to The excessive trapped bed sediments deposition along the upper reaches is responsible for the shallower of river embankment leading to rapid overflow during flooding.
At the Chao Phraya River mouth, a total of This is caused by the reducing of sediment supply leading to non-equilibrium in the deltaic zone of the upper Gulf of Thailand. There are several possibility implications from this study involving construction of weir, in-channel sand mining, reservoir sedimentation and coastal erosion management. Riverbank erosion is a serious environmental issue which urges government to take appropriate action to solve this problem.
Kilim River, Langkawi Geopark which is located at the northern part in Peninsular Malaysia is now under the threat Kilim River, Langkawi Geopark which is located at the northern part in Peninsular Malaysia is now under the threat of critical reduction caused by intensification of tourism activities. The purpose of this study is to assess riverbank erosion by using combination of geospatial techniques consist of high resolution imagery and unmanned aerial vehicle UAV approaches.
Both images from UAV and Quickbird is rectify and process by using GIS and remote sensing software in order to determine the erosion area of river, based on Kilim River area comparison between until Subsequently, Empirical Bayesian Kriging EBK analysis become main option to predict riverbank erosion in future based on present erosion data by using interpolation method and the other method of interpolation is also used as the comparison.
The finding shows that the Kilim River is changes during in between and due to several factors such as boat wakes and sea level rise SLR.
The area of Kilim River is increasing from If it continuously happens, more area of mangrove forest will be eroded in the future. Interpolation of riverbank erosion in future indicates about more than 30 acres of mangrove riverbank erosion will be eroded for the next 10 years. For this study, perhaps the geospatial technologies are can be utilized in environmental study for detection of riverbank erosion.
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Spatio-temporal analysis of river morphological changes and erosion detection using very high resolution satellite image. Spatio-temporal analysis of Kilim River using Very High-Resolution VHR satellite image between the years of and are vital to assess river morphological changes and erosion detection over the specific time duration.
Therefore, this study utilizes remote sensing and Geographical Information System GIS capabilities to identify the channel migration and shifting as well as to calculate the rate of erosion and accretion. Classification of the river from Quickbird and WorldView-2 images is carry out using Maximum Likelihood Classification MLC technique whereas feature selection tool performs to extract river feature from the raw image. Subsequently, river feature been overlaid to identify the changes of riverbank pattern and to calculate the rate of riverbank erosion in terms of area.
The result shows the total area of erosion is A maximum erosion of The rates of riverbank erosion are Hence, the output of this study enables Langkawi Development Authority LADA and other stakeholders to recognize the specific location, which severely affected by erosion and accretion as well as to spot the area experienced huge river channel shifting.
Widmer A. Andererseits sollen konkrete Beispiele, Planskizzen und detaillierte Angaben zu Projektierung und Bau anregen, ELJs in weiteren Flussbauprojekten in Europa einzusetzen, wobei die Chancen und Grenzen dieser neuen Bauweisen transparent dargelegt werden. Bhagirathi River is one of the main rivers in Burdwan District. River shapes surrounding landscapes is changed by several hydrodynamic and subsequent morpho dynamic processes. Bhagirath river, eastern part of Burdwan district mainly Water discharge, soil types and transportation of sediment is the major contributing factor of morphological changes like bar or shoal, ox-bow lake, meander etc.
In this paper an attempt has been made to get the nature of shifting, direction of shifting, sinuosity index measurement, area changing direction through the help of using Remote Sensing, GIS Software. Keywords: Morphometry, River shifting, Changing river course, sinuosity, remote sensing, talweg length. Are equilibrium multichannel networks predictable? The case of the regulated Indus River, Pakistan.
Arguably, the current planform behaviour of the Indus River is broadly predictable. Between Chashma and Taunsa, Pakistan, the Indus is a km-long multiple-channel reach. Remote sensing imagery, encompassing major floods in and Remote sensing imagery, encompassing major floods in and , shows that the Indus has a minimum of two and a maximum of nine channels, with on average four active channels during the dry season and five during the annual monsoon. The MFE principle indicates that stable networks have three to four channels, thus the observed stability in the number of active channels accords with the presence of a near-equilibrium reach-scale channel network.
Insensitivity to the annual hydrological cycle demonstrates that the timescale for network adjustment is much longer than the timescale of the monsoon hydrograph, with the annual excess water being stored on floodplains rather than being conveyed in an enlarged channel network. The analysis explains the lack of significant channel adjustment following the largest flood in 40 years and the extensive Indus flooding experienced on an annual basis, with its substantial impacts on the populace and agricultural production.
Landscape is reevaluated as one of the most powerful and effective strategies for transformation projects with its multi-dimensional and process-based structure. For the last decade, the theories evolved within the interdisciplinary For the last decade, the theories evolved within the interdisciplinary platform offer a new way of understanding landscape as a source for the development of urban and rural environment.
Among those theories, Landscape Urbanism appears to be one of the most promising fields of action, as it redefines the performance ground of landscape designs.
Appreciated as one of the major ecological corridors of the region and serving as a fertile agricultural land, Dicle River has been threatened by redevelopment projects since the late seventies, losing its socio-cultural and ecological quality. In this context, the project focuses on reevaluation of the sites existing character, and proposes a design scheme to transform the ha.
To respond to the current environmental conditions and competition brief, the proposed project is structured around four landscape strategies: integration, restructuring, multi-functionality, and flux. In the light of interdisciplinary design approach, the design strategies are used to reconstruct the bounds between nature and culture.
Ecology, socio-cultural transformation, and spatial characteristics that foster new functions appeared to be important ideas, accompanied by the design strategies, which are inspired from the existing site conditions to propose a new development scenario. With its urban position and rural character, Dicle Valley confronts different dimensions of a space, history, ecology, urban development, and socio-cultural transformation. As a by-product of a design competition, it suggests an approach drawn from the theory of landscape urbanism to stimulate landscape-based strategies.
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River Channel Relocation: Problems and Prospects. River relocation is the diversion of a river into an entirely new channel for part of their length often called river diversions. Relocations have been common through history and have been carried out for a wide range of purposes, but Relocations have been common through history and have been carried out for a wide range of purposes, but most commonly to construct infrastructure and for mining. However, they have not been considered as a specific category of anthropogenic channel change.
Relocated channels present a consistent set of physical and ecological challenges, often related to accelerated erosion and deposition.
We present a new classification of river relocation, and present a series of case studies that highlight some of the key issues with river relocation construction and performance. Primary changes to the channel dimensions and materials, alongside changes to flow velocity or channel capacity, can lead to a consistent set of problems, and lead to further secondary and tertiary issues, such as heightened erosion or deposition, hanging tributaries, vegetation loss, water quality issues, and associated ecological impacts.
Related River Morphology
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