scholarly journals North to South Variations in the Suspended Sediment Transport Budget within Large Siberian River Deltas Revealed by Remote Sensing Data

2021 ◽  
Vol 13 (22) ◽  
pp. 4549
Author(s):  
Sergey Chalov ◽  
Kristina Prokopeva ◽  
Michał Habel
Keyword(s):  
Remote Sensing ◽  
Sediment Transport ◽  
Suspended Sediment ◽  
Aquatic Vegetation ◽  
River Sediments ◽  
The Arctic ◽  
Suspended Sediment Transport ◽  
Forest Steppe ◽  
Siberian River ◽  
River Deltas

This study presents detailed suspended sediment budget for the four Siberian river deltas, representing contrasting conditions between Northern and Southern environments. Two of the studied rivers empty their water and sediments into the marine located in the permafrost zone in the Arctic region (Lena and Kolyma), and the other two (Selenga and Upper Angara) flow into Lake Baikal located in the steppe and forest-steppe zone of Southern Siberia. For the first time, these poorly monitored areas are analyzed in terms of the long-term and seasonal changes of spatial patterns of suspended sediment concentrations (SSC) over distributaries systems. Remote sensing reflectance is derived from continuous time series of Landsat images and calibrated with the onsite field measurements of SSC. Seasonal variability of suspended sediment changes over deltas was captured for the period from 1989 to 2020. We identify significant variability in the sedimentation processes between different deltas, which is explained by particularities of deltas networks and geomorphology and the existence of specific drivers—continuous permafrost impact in the North and abundant aquatic vegetation and wetland-dominated areas in the South. The study emphasizes that differences exist between Northern and Southern deltas regarding suspended sediments transport conditions. Mostly retention of suspended sediment is observed for Southern deltas due to sediment storage at submerged banks and marshlands located in the backwater zone of the delta during high discharges. In the Northern (arctic) deltas due to permafrost impacts (melting of the permafrost), the absence of sub-aquatic banks and river to ocean interactions of suspended sediment transport is mostly increased downwards, predominantly under higher discharges and along main distributary channels. These results shine light on the geochemical functions of the deltas and patterns of sequestering various metals bound to river sediments.

Study on the Coastal Suspended Sediment Transport Based on Multi-Source Satellite Remote Sensing Imagery

2013 ◽  
Vol 718-720 ◽  
pp. 371-376
Author(s):  
Yin Cai ◽  
Meng Guo Li ◽  
Ming Xiao Xie
Keyword(s):  
Remote Sensing ◽  
Sediment Transport ◽  
Suspended Sediment ◽  
Coastal Area ◽  
Satellite Remote Sensing ◽  
Wind Waves ◽  
Suspended Sediment Transport ◽  
Nearshore Zone ◽  
Retrieval Technique ◽  
Suspended Sediment Concentrations

Based on a series of multi-source satellite remote sensing imageries and wind parameters extracted from QuickSCAT satellite datasets, the surface suspended sediment concentrations (SSC) of the Zhuanghe coastal area, China was investigated using the retrieval technique. The results showed that the SSC of the Zhuanghe coastal area is higher in the nearshore zone, and gradually diminishes to the offshore. During the ebbing process, the range of high SSC zone is wider than that during the flooding process. This feature indicated that the suspended sediment transport is mainly determined by the ebb currents, and the sediment source comes from the nearshore shallow flats, where the sediments could be entrained by the wind waves and then diffuses offshore or alongshore with the tidal currents.

scholarly journals Interactions between aquatic vegetation, hydraulics and fine sediment

2020 ◽  
Author(s):  
Hamish Biggs ◽  
Arman Haddadchi ◽  
Murray Hicks
Keyword(s):  
Sediment Transport ◽  
Suspended Sediment ◽  
Hydraulic Resistance ◽  
Vegetation Cover ◽  
Aquatic Vegetation ◽  
Fine Sediment ◽  
Suspended Sediment Transport ◽  
Sediment Delivery ◽  
Lowland Streams ◽  
Mechanical Removal

Aquatic vegetation, hydraulics and sediment transport have complex interactions that are not yet well understood. These interactions are important for sediment conveyance, sediment sequestration, phasing of sediment delivery from runoff events, and management of ecosystem health in lowland streams. To address this knowledge gap detailed field measurements of sediment transport through natural flexible aquatic vegetation are required to supplement and validate laboratory results. This paper contributes a field study of suspended sediment transport through aquatic vegetation and includes mechanical removal of aquatic vegetation with a weed cutting boat. It also provides methods to quantify vegetation cover through remote sensing with Unmanned Aerial Vehicles (UAVs) and estimate biomass from ground truth sampling. Suspended sediment concentrations were highly dependent on aquatic vegetation abundance, and the distance upstream that had been cleared of aquatic vegetation. When the study reach was fully vegetated (i.e. cover >80%), the maximum recorded SSC was 14.6 g/m (during a fresh with discharge of 2.47 m/s), during weed cutting operations SSC was 76.8 g/m at 0.84 m/s (weedcutting boat 0.5-1 km upstream from study reach), however following weed cutting operations (4.6 km cleared upstream), SSC was 139.0 g/m at a discharge of 1.52 m/s. The data indicates that fine sediment was being sequestered by aquatic vegetation and likely remobilised after vegetation removal. Investigation of suspended sediment spatial dynamics illustrated changes in particle size distribution due to preferential settling of coarse particles within aquatic vegetation. Hydraulic resistance in the study reach (parameterized by Manning’s n) dropped by over 70% following vegetation cutting. Prior to cutting hydraulic resistance was discharge dependent, while post cutting hydraulic resistance was approximately invariant of discharge. Aerial surveying captured interesting changes in aquatic vegetation cover, where some very dense regions of aquatic vegetation were naturally removed leaving behind unvegetated riverbed and fine sediment.

scholarly journals Numerical Study of Remote Sensed Dredging Impacts on the Suspended Sediment Transport in China’s Largest Freshwater Lake

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2449 ◽  
Author(s):  
Jianzhong Lu ◽  
Haijun Li ◽  
Xiaoling Chen ◽  
Dong Liang
Keyword(s):  
Remote Sensing ◽  
Sediment Transport ◽  
Suspended Sediment ◽  
Transport Model ◽  
Poyang Lake ◽  
Numerical Study ◽  
Point Sources ◽  
Freshwater Lake ◽  
Suspended Sediment Transport ◽  
Sediment Transport Model

As the largest freshwater lake in China, Poyang Lake plays an important role in the ecosystem of the Yangtze River watershed. The high suspended sediment concentration (SSC) has been an increasingly significant problem under the influence of extensive sand dredging. In this study, a hydrodynamic model integrated with the two-dimensional sediment transport model was built for Poyang Lake, considering sand dredging activities detected from satellite images. The sediment transport model was set with point sources of sand dredging, and fully calibrated and validated by observed hydrological data and remote sensing results. Simulations under different dredging intensities were implemented to investigate the impacts of the spatiotemporal variation of the SSC. The results indicated that areas significantly affected by sand dredging were located in the north of the lake and along the waterway, with a total affected area of about 730 km2, and this was one of the main factors causing high turbidity in the northern part of the lake. The SSC in the northern area increased, showing a spatial pattern in which the SSC varied from high to low from south to north along the main channel, which indicated close agreement with the results captured by remote sensing. In summary, this study quantified the influence of human induced activities on sediment transport for the lake aquatic ecosystem, which could help us to better understand the water quality and manage water resources.

3-D Simulation of the Suspended Sediment Transport in the Jiao jiang Estuary: Based on Validating by Remote Sensing Retrieval

2018 ◽  
Vol 85 ◽  
pp. 116-120 ◽  
Author(s):  
Cuizhuo Lu ◽  
Huan Li ◽  
Weiqi Dai ◽  
Jianfeng Tao ◽  
Fan Xu ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Sediment Transport ◽  
Suspended Sediment ◽  
Suspended Sediment Transport

Suspended sediment transport mapped by satellite remote sensing

2008 ◽  
Author(s):  
P. Shanmugam ◽  
Y. H. Ahn ◽  
H. R. Yoo ◽  
B. C. Suk ◽  
J. H. Ryu
Keyword(s):  
Remote Sensing ◽  
Sediment Transport ◽  
Suspended Sediment ◽  
Satellite Remote Sensing ◽  
Suspended Sediment Transport

2D and 3D CFD Investigations of Seabed Shear Stresses Around Subsea Pipelines

2013 ◽  
Author(s):  
Wenwen Shen ◽  
Terry Griffiths ◽  
Mengmeng Xu ◽  
Jeremy Leggoe
Keyword(s):  
Sediment Transport ◽  
Suspended Sediment ◽  
Interaction Model ◽  
Suspended Sediment Transport ◽  
Shear Stresses ◽  
Parametric Function ◽  
Ample Evidence ◽  
North West ◽  
Wide Range ◽  
Subsea Pipelines

For well over a decade it has been widely recognised that existing models and tools for subsea pipeline stability design fail to account for the fact that seabed soils tend to become mobile well before the onset of pipeline instability. Despite ample evidence obtained from both laboratory and field observations that sediment mobility has a key role to play in understanding pipeline/soil interaction, no models have been presented previously which account for the tripartite interaction between the fluid and the pipe, the fluid and the soil, and the pipe and the soil. There are numerous well developed and widely used theories available to model pipe-fluid and pipe-soil interactions. A challenge lies in the way to develop a satisfactory fluid-soil interaction algorithm that has the potential for broad implementation under both ambient and extreme sea conditions due to the complexity of flow in the vicinity of a seabed pipeline or cable. A widely used relationship by Shields [1] links the bedload and suspended sediment transport to the seabed shear stresses. This paper presents details of computational fluid dynamics (CFD) research which has been undertaken to investigate the variation of seabed shear stresses around subsea pipelines as a parametric function of pipeline spanning/embedment, trench configuration and wave/current properties using the commercial RANS-based software ANSYS Fluent. The modelling work has been undertaken for a wide range of seabed geometries, including cases in 3D to evaluate the effects of finite span length, span depth and flow attack angle on shear stresses. These seabed shear stresses have been analysed and used as the basis for predicting sediment transport within the Pipe-Soil-Fluid (PSF) Interaction Model [2] in determining the suspended sediment concentration and the advection velocity in the vicinity of pipelines. The model has significant potential to be of use to operators who struggle with conventional stabilisation techniques for the pipelines, such as those which cross Australia’s North West Shelf, where shallow water depths, highly variable calcareous soils and extreme metocean conditions driven by frequent tropical cyclones result in the requirement for expensive and logistically challenging secondary stabilisation measures.

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