Facies characteristics and cyclicity of Lower Siwalik sediments, Jammu area: a new perspective

The Lower Siwalik succession of the Jammu area has been distinguished into three major lithofacies associations: a sand-dominant association, a sandy-mud-dominant association, and a silty-heterolithic association. The sand-dominant association is made up of three lithofacies: cross-bedded sandstone, rippled silty sandstone and bioturbated sandy siltstone, which are organized in multi-storeyed sandbodies representing deposition in major river channels. The sandy-mud-dominant association is made up of two lithofacies, mottled clayey siltstone and interbedded sandstone, siltstone and mudstone, representing deposition in overbank areas of flood-plain and natural levee-crevasse splays. The sand-dominant association and sandy-mud-dominant association are grouped together as a channel-related succession and are products of processes in the river channel. The silty-heterolithic association consists of four lithofacies: mottled siltstone, mottled silty sandstone, bedded calcrete and mottled mudstone. They are considered to be deposits of Doab (upland interfluve) areas operating independently of present-day major river channels. These deposits have been formed in minor channels, sloping surfaces, and lakes and ponds of the interfluve regions. The cyclicity of both successions (channel-related and Doab-related) has been determined using a partial-independence statistical model.

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Quantitative analysis of randomness exhibited by river channels using chaos game technique: Mississippi, Amazon, Sava and Danube case studies

Nonlinear Processes in Geophysics ◽

10.5194/npg-16-419-2009 ◽

2009 ◽

Vol 16 (3) ◽

pp. 419-429 ◽

Cited By ~ 1

Author(s):

G. Žibret ◽

T. Verbovšek

Keyword(s):

Sampling Rate ◽

Fractal Dimensions ◽

River Channel ◽

Danube River ◽

River Channels ◽

Complex Curves ◽

Sierpinski Triangle ◽

Major River ◽

Chaos Game ◽

Random Behaviour

Abstract. This paper presents a numerical evaluation of the randomness which can be observed in the geometry of major river channels. The method used is based upon that of generating a Sierpinski triangle via the chaos game technique, played with the sequence representing the river topography. The property of the Sierpinski triangle is that it can be constructed only by playing a chaos game with random values. Periodic or chaotic sequences always produce an incomplete triangle. The quantitative data about the scale of the random behaviour of the river channel pathway was evaluated by determination of the completeness of the triangle, generated on the basis of sequences representing the river channel, and measured by its fractal dimension. The results show that the most random behaviour is observed for the Danube River when sampled every 715 m. By comparing the maximum dimension of the obtained Sierpinski triangle with the gradient of the river we can see a strong correlation between a higher gradient corresponding to lower random behaviour. Another connection can be seen when comparing the length of the segment where the river shows the most random flow with the total length of the river. The shorter the river, the denser the sampling rate of observations has to be in order to obtain a maximum degree of randomness. From the comparison of natural rivers with the computer-generated pathways the most similar results have been produced by a complex superposition of different sine waves. By adding a small amount of noise to this function, the fractal dimensions of the generated complex curves are the most similar to the natural ones, but the general shape of the natural curve is more similar to the generated complex one without the noise.

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Numerical Simulation of Effects of River Reconstruction on Flooding: A Case Study of the Ba River, China

Advances in Materials Science and Engineering ◽

10.1155/2021/5538059 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Haixiao Jing ◽

Yongbiao Lang ◽

Xinhong Wang ◽

Mingyang Yang ◽

Zongxiao Zhang

Keyword(s):

Flow Velocity ◽

Eddy Currents ◽

Human Life ◽

River Channel ◽

Computational Domain ◽

River Channels ◽

One Dimensional ◽

Local Reconstruction ◽

Before And After ◽

Flood Flow

The local reconstruction of river channels may pose obstacles of flood flow, local eddy currents, or high flow velocity which pose potential threats to human life and infrastructures nearby. In the design of such projects, the effects of local reconstruction of the river channel on flooding are often evaluated by the one-dimensional method, which is based on the formula of one-dimensional nonuniform flow. In this study, a two-dimensional hydrodynamic model based on shallow water equations is employed to investigate the impacts of river reconstruction on flooding in the Ba River, China. The finite volume method and an unstructured triangular mesh are used to solve the governing equations numerically. The numerical model is validated by comparison with the results of a physical model of 1 : 120 scale. The backwater effects and impacts of flood flow fields under two flood frequencies are analyzed by comparing the numerical results before and after local reconstruction. The results show that the backwater length under both 10-year and 100-year floods can be reached up to the upstream boundary of the computational domain. However, the maximum water level rises are limited, and the levees in this river channel are safe enough. The flow velocity fields under both floods are changed obviously after local reconstruction in the Ba River. Areas with the potential for scour and deposition of the river bed are also pointed out. The findings of this study are helpful for the evaluation of flood risks of the river.

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Response of the Snowy River Estuary to two environmental flows

Proceedings of the Royal Society of Victoria ◽

10.1071/rs15016 ◽

2015 ◽

Vol 127 (2) ◽

pp. 28

Author(s):

Errol J. McLean ◽

Jon B. Hinwood

Keyword(s):

Fresh Water ◽

Peak Flow ◽

Environmental Flows ◽

River Estuary ◽

Environmental Flow ◽

River Channel ◽

Salinity Gradients ◽

Tasman Sea ◽

Eastern Australia ◽

Major River

The Snowy River is a major river in south-eastern Australia, discharging to the Tasman Sea via a barrier estuary, with its entrance constricted by marine sands. Since the construction of the Snowy Mountains Scheme, river flows have not been sufficient to maintain the river channel. A program of environmental flow releases (EFR) is returning water to the river to restore the fluvial reaches and is now trialling flow regimes that may also benefit the estuarine reaches. This paper documents the response of the estuarine segments of the Snowy River to two EFRs; the release in 2010 was designed to scour the upper reaches of the Snowy River while the larger 2011 release was intended to extend the scouring downstream. For each release, the effects on the entrance morphology, tides and salinity through the flow peak and recovery are described. Each EFR caused minor increases in depth and very minor longshore movement of the entrance channel, although each EFR had been preceded by a larger fresh flow that would have scoured the channels. The small increase in fresh water inflow in the 2010 EFR pushed salinity contours seawards and steepened vertical salinity gradients. The larger inflow in the 2011 EFR purged the upper estuary of saltwater. After the peak flow, salinity recovery was rapid in the principal estuarine channels but took weeks where poorly connected wetlands could store fresh flood waters. Critical flows for scouring the entrance and purging salinity are estimated.

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An Improved Method Constructing 3D River Channel for Flood Modeling

Water ◽

10.3390/w11030403 ◽

2019 ◽

Vol 11 (3) ◽

pp. 403 ◽

Cited By ~ 3

Author(s):

Pengbo Hu ◽

Jingming Hou ◽

Zaixing Zhi ◽

Bingyao Li ◽

Kaihua Guo

Keyword(s):

High Resolution ◽

River Channel ◽

Hydrodynamic Process ◽

River Channels ◽

Section Data ◽

Terrain Model ◽

Digital Elevation ◽

Hydrodynamic Processes ◽

Hermite Spline ◽

Elevation Model

The high-resolution topography is very crucial to investigate the hydrological and hydrodynamic process. To resolve the deficiency problem of high resolution terrain data in rivers, the Quartic Hermite Spline with Parameter (QHSP) method constructing the river channel terrain based on the limited cross-section data is presented. The proposed method is able to not only improve the reliability of the constructed river terrain, but also avoid the numerical oscillations caused by the existing constructing approach, e.g., the Cubic Hermite Spline (CHS) method. The performance of the proposed QHSP method is validated against two benchmark tests. Comparing the constructed river terrains, the QHSP method can improve the accuracy by at least 15%. For the simulated flood process, the QHSP method could reproduce more acceptable modeling results as well, e.g., in Wangmaogou catchment, the numerical model applying the Digital Elevation Model (DEM) produced by the QHSP method could increase the reliability by 18.5% higher than that of CHS method. It is indicated that the QHSP method is more reliable for river terrain model construction than the CHS and is a more reasonable tool investigating the hydrodynamic processes in river channels lacking of high resolution topography data.

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Variations in natural levee morphology in anastomosed channel flood plain complexes

Geomorphology ◽

10.1016/j.geomorph.2003.10.005 ◽

2004 ◽

Vol 61 (1-2) ◽

pp. 127-142 ◽

Cited By ~ 56

Author(s):

Peter N Adams ◽

Rudy L Slingerland ◽

Norman D Smith

Keyword(s):

Flood Plain ◽

Natural Levee

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Spatial variation of ostracod (Crustacea, Ostracoda) egg banks in temporary lakes of a tropical flood plain

Marine and Freshwater Research ◽

10.1071/mf19081 ◽

2021 ◽

Vol 72 (1) ◽

pp. 26

Author(s):

Jonathan Rosa ◽

Ramiro de Campos ◽

Koen Martens ◽

Janet Higuti

Keyword(s):

Spatial Variation ◽

Flood Plain ◽

Resting Eggs ◽

River Channels ◽

Aquatic Communities ◽

Lake Ecosystems ◽

Flood Plains ◽

Adverse Conditions ◽

Egg Banks ◽

Flood Pulses

Ostracods are microcrustaceans that produce resting eggs under adverse conditions. In this study we evaluated the spatial variation of ostracod resting eggs in different regions of temporary lakes in a Brazilian flood plain. Based on the homogenisation effect of flood pulses on aquatic communities in flood plains, we hypothesised that the composition and abundance of ostracod eggs in the centre of temporary lakes would be similar to those in edge regions. Samples were collected from the centre and edge regions of five temporary lakes. Sediment was oven dried, rehydrated and hatching was monitored in germinating chambers. Twelve ostracod species hatched from the egg banks during our experiments. The abundance and species composition were similar between the two regions of the lakes. Flood events may be responsible for the homogenisation of the egg banks as a result of the connection of lakes with principal river channels. During flooding, water masses powerfully enter lakes and can redistribute sediments. This study shows that egg banks have the potential to contribute to the maintenance of local biodiversity and the resilience of biodiversity of temporary lake ecosystems.

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Response, Remediation and Risk Management of a Crude Oil Pipeline Spill

Volume 2: Design and Construction; Pipeline Automation and Measurement; Environmental Issues; Rotating Equipment Technology ◽

10.1115/ipc1998-2117 ◽

1998 ◽

Author(s):

J. T. Doupe ◽

W. R. Livingstone

Keyword(s):

Crude Oil ◽

Action Plan ◽

Human Health Risk ◽

Ground Surface ◽

Flood Plain ◽

Ecological Impacts ◽

Monitoring Wells ◽

Oil Pipeline ◽

Subgrade Soils ◽

Major River

In December 1995, an oil spill was discovered along a section of pipeline located near the bank of a major river, less than 1 km upstream of the water supply intake of a southern Alberta community. The spill, which involved light crude oil, was observed at ground surface over an area of approximately 3 000 m2 at the top of the river slope and had also migrated downslope through the subgrade soils and along the groundwater table toward the river. The initial emergency response activities consisted of removing and disposing of oil-stained vegetation and snow, and the containment and recovery of free oil pooled on ground surface. Subsequent subsurface assessments involved the drilling of test holes and boreholes, and installation of groundwater monitoring/recovery wells. Based on the results of these assessments, a remedial action plan was developed. As part of this plan, some of the impacted soils were excavated and placed in lined treatment cells for bioremediation. The limits of the excavation were based on field screening measurements and on soil clean-up criteria developed through an assessment of the human health risk and ecological impacts. Investigations conducted at the site also indicated that phase-separated crude oil had migrated further downslope and had accumulated at the water table within the flood plain sediments adjacent to the river. Therefore, remediation systems were installed to recover the oil, recover and treat the impacted groundwater, and prevent further migration of the impacted groundwater and oil toward the river. Impacted groundwater recovered from the flood plain deposits was treated onsite and was then injected back into the flood plain deposits via an infiltration gallery. The performance of the pumping and remediation systems was monitored regularly and water samples were recovered from the treatment system, selected monitoring wells and the river. Based on the results of these analyses, the quality of local groundwater steadily improved and the zone of impacted water was effectively contained.

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Sediment origins across the terrestrial-aquatic continuum: climate threat mitigation and promotion of water quality

10.5194/egusphere-egu2020-2637 ◽

2020 ◽

Author(s):

Katy Wiltshire ◽

Toby Waine ◽

Bob Grabowski ◽

Miriam Glendell ◽

Steve Addy ◽

...

Keyword(s):

Water Quality ◽

Soil Erosion ◽

Soil Loss ◽

River Channel ◽

River Channels ◽

Catchment Scale ◽

Transport Pathways ◽

Fine Grained ◽

Erosion Rates ◽

Erosion Modelling

Although fine-grained sediment (FGS) is a natural component of river systems, increased fluxes can impact FGS levels to such an extent they cause detrimental, irreversible changes in the way rivers function intensifying flood risk and negatively affecting water quality.Previous catchment scale studies indicate there is no simple link between areas of sediment loss and the organic carbon (OC) load in waterways; areas with a high soil loss rate may not contribute most sediment to the rivers and areas that contribute the most sediment may not contribute the most OC. Anthropogenic and climate changes can accelerate soil erosion and the role of soil OC transported by erosional processes in the fluxes of C between land, water and atmosphere is still debated. Tracing sediment pathways, likely depositional areas and connections to streams leads to better assumptions about control processes and better estimation of OC fluxes.In this innovative study OC fingerprinting of sediment reaching a catchment&#8217;s waterbodies is combined with OC stock and erosion modelling of the terrestrial catchment. Initial results show disconnect between catchment OC loss erosion modelling and fingerprinting results, which could be due to failure to model connectivity between the land and river channel. The current soil erosion model RUSLE (Revised Universal Soil Loss Equation) calculates only the spatial pattern of mean annual soil erosion rates. Using the WaTEM SEDEM model, which in includes routing (and possible en route deposition) of eroded sediments to river channels, we aim to determine the dominant source of OC within catchment streams by identification of both the land-use specific areas with the highest OC loss and the transport pathways between the sources and river channel.

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