scholarly journals Quarternary Sediment Characteristics of Floodplain area: Study Case at Kampar River, Rumbio Area and Surroundings, Riau Province

2018 ◽  
Vol 3 (1) ◽  
pp. 63
Author(s):  
Yuniarti Yuskar ◽  
Dewandra Bagus Eka Putra ◽  
Muhammad Revanda
Keyword(s):  
River System ◽  
Fine Sand ◽  
Sediment Deposition ◽  
Sediment Supply ◽  
Lateral Spread ◽  
Stream Channel ◽  
Terrestrial Organic Matter ◽  
Depositional Facies ◽  
Meandering River ◽  
Sand Bars

The study area is located in some floodplains of meandering river environment along the Kampar River, Rumbio. Typical morphology of meandering river that found in this area can be classified as stream channel, floodplain, abandoned channel, and sand bars deposit. Meandering river system carries sediment supply by suspended and bed - load (mixed load) in conjunction with low energy into a particular characteristic on sediment deposition. This study aims to determine the characteristics of the sediments, changes in vertical and lateral spread of sediment deposition on the floodplain environment. This study conducted by field survey using a hand auger of 1.5m - 4m depth and trenching which is a layer that has been exposed of 1-2 meters depth. Further analysis had been carried out using granulometri method and core data analysis to determine the characteristics and depositional facies. Sediment deposit that formed along the Kampar River is the result of the main channel migration of Kampar River. The characteristic of quaternary sediment facies is coarse to gravelly sand on the bottom followed by fine to very fine sand with pattern fining upwards and silt to clay and abundant terrestrial organic matter at the uppermost layer. Depositional facies are determined based on the characteristics of sediment facies which can be grouped into a stream channel, oblique accretion deposits, sand bars and overbank deposits.

An analysis of the molluscs from an Ipswichian interglacial river channel deposit at Maxey, Cambridgeshire, England

1982 ◽  
Vol 119 (6) ◽  
pp. 593-598 ◽  
Author(s):  
C. A. I. French
Keyword(s):  
River System ◽  
River Channel ◽  
Side Channel ◽  
Stream Channel ◽  
Meandering River ◽  
Water Conditions ◽  
Summer Temperatures ◽  
Molluscan Assemblage ◽  
Channel Deposit

SummaryA freshwater and land molluscan assemblage from an Ipswichian stream channel at Maxey, Cambridgeshire, is discussed. The presence of Belgrandia marginata and Vallonia enniensis suggests that summer temperatures may have been somewhat warmer in the Ipswichian period. The assemblage represents the silting processes under relatively quiet water conditions, possibly in a side channel or backwater of a meandering river system.

Feasibility of sedimentation strategies for the Mekong delta to counterbalance relative sea-level rise

2021 ◽  
Author(s):  
Frances E. Dunn ◽  
Philip S. J. Minderhoud
Keyword(s):  
Land Use ◽  
Sea Level Rise ◽  
Sea Level ◽  
Mekong Delta ◽  
Sediment Deposition ◽  
Sediment Supply ◽  
Sediment Flux ◽  
Relative Sea Level ◽  
Fluvial Sediment ◽  
Relative Sea Level Rise

<p>As one of the largest deltas in the world, the Mekong delta is home to over 17 million people and supports internationally important agriculture. Recently deposited sediment compacts and causes subsidence in deltas, so they require regular sediment input to maintain elevation relative to sea level. These processes are complicated by human activities, which prevent sediment deposition indirectly through reducing fluvial sediment supply and directly through the construction of flood defence infrastructure on deltas, impeding floods which deliver sediment to the land. Additionally, anthropogenic activities increase the rate of subsidence through the extraction of groundwater and other land-use practices.</p><p>This research shows the potential for fluvial sediment delivery to compensate for sea-level rise and subsidence in the Mekong delta over the 21st century. We use detailed elevation data and subsidence scenarios in combination with regional sea-level rise and fluvial sediment flux projections to quantify the potential for maintaining elevation relative to sea level in the Mekong delta. We present four examples of localised sedimentation scenarios in specific areas, for which we quantified the potential effectiveness of fluvial sediment deposition for offsetting relative sea-level rise. The presented sediment-based adaptation strategies are complicated by existing land use, therefore a change in water and sediment management is required to effectively use natural resources and employ these adaptation methods. The presented approach could be an exemplar to assess sedimentation strategy feasibility in other delta systems worldwide that are under threat from sea-level rise.</p>

scholarly journals Assessment of Morpho-Dynamics through Geospatial Techniques within the Padma-Meghna and Ganges-Jamuna River Confluences, Bangladesh

2020 ◽  
Vol 70 (3) ◽  
pp. 127-139
Author(s):  
Md. Yousuf Gazi ◽  
Himel Roy ◽  
Md. Bodruddoza Mia ◽  
Syed Humayun Akhter
Keyword(s):  
River System ◽  
Policy Makers ◽  
Geospatial Techniques ◽  
Sand Bars ◽  
Multi Temporal ◽  
Migration Dynamics ◽  
Major River ◽  
River Confluences ◽  
Sand Bar ◽  
Landsat Satellite

Abstract Bangladesh is a low-lying riverine country with the mighty Ganges–Brahmaputra–Meghna (GBM) major river system including their abundant tributaries and distributaries. Land erosion–accretion is a very common phenomenon in this riverine country. This process extensively erodes huge productive landmasses at the river confluence zones every year. The main objective of this study was to understand the confluence morpho-dynamics and identify the vulnerable areas near the Padma–Meghna Confluence (PMC) and Ganges–Jamuna confluence (GJC) due to confluence shifting and erosion–accretion phenomenon of those rivers. The present study utilized multi-temporal Landsat satellite images from 1972 to 2019 approximately ten years of interval. Results showed that the PMC indicated frequent variation in migration trend towards NW from 1972 to 1980, SE from 1980 to 2010, and then reversed towards NW direction from 2010 to 2019. On the other hand, the GJC confluence point moved NW direction (2.37 km) from the year 1972 to 1980, but from 1980 to 2019, the confluence shifted towards the SE direction. Due to the migration dynamics, huge changes happened in width and sand bars area of both confluences. In PMC, confluence width increased remarkably indicating erosive flow during 1972–1980, then progressively shortened up to 2019, indicating accretion. In contrast, GJC shows a significant accretional trend over the 47 years. The sand bar area of the PMC increased about 147.09 km2 throughout the study period. But, GJC shows an opposite scenario where the total sand bar area decreased about 51.02 km2 in the same period. From the vulnerability study of erosion–accretion scenarios, it is predicted that Paturia Ferry Ghat area, Aricha Ferry Ghat area, Arua, Baruria, Dashkin Saljana, Bhadiakola, Masundia, Khanganj and Nyakandi areas near GJC and Chandpur sadar, Srimandi, Sakhua, Bilaspur and char Atra near PMC are highly vulnerable zones. The outputs of the study will enable policy makers to take necessary measures to reduce the erosional severity on both confluence zones and could also provide a basis for proper land management.

scholarly journals Sedimentary facies analysis of the fluvial systems in the Siwalik Group, Karnali River section, Nepal Himalaya, and their significance for understanding the paleoclimate and Himalayan tectonics

2016 ◽  
Vol 51 ◽  
pp. 11-26 ◽  
Author(s):  
Ashok Sigdel ◽  
Tetsuya Sakai
Keyword(s):  
River System ◽  
Precipitation Pattern ◽  
Braided River ◽  
River Section ◽  
Meandering River ◽  
Braided Rivers ◽  
Facies Associations ◽  
Siwalik Group ◽  
Himalayan Tectonics ◽  
Flood Flow

Fluvial sediments of the Siwalik successions in the Himalayan Foreland Basin are one of the most important continental archives for the history of Himalayan tectonics and climate change during the Miocene Period. This study reanalyzes the fluvial facies of the Siwalik Group along the Karnali River, where the large paleo-Karnali River system is presumed to have flowed. The reinterpreted fluvial system comprises fine-grained meandering river (FA1), flood-flow dominated meandering river with intermittent appearance of braided rivers (FA2), deep and shallow sandy braided rivers (FA3, FA4) to gravelly braided river (FA5) and finally debris-flow dominated braided river (FA6) facies associations, in ascending order. Previous work identified sandy flood-flow dominated meandering and anastomosed systems, but this study reinterprets these systems as a flood-flow dominated meandering river system with intermittent appearance of braided rivers, and a shallow sandy braided system, respectively. The order of the appearance of fluvial depositional systems in the Karnali River section is similar to those of other Siwalik sections, but the timing of the fluvial facies changes differs. The earlier appearance (3-4 Ma) of the flood-flow dominated meandering river system in the Karnali River section at about 13.5 Ma may have been due to early uplift of the larger catchment size of the paleo-Karnali River which may have changed the precipitation pattern i.e. intensification of the Indian Summer Monsoon. The change from a meandering river system to a braided river system is also recorded 1 to 3 Ma earlier than in other Siwalik sections in Nepal. Differential and diachronous activities of the thrust systems could be linked to change in catchment area as well as diachronous uplift and climate, the combination of which are major probable causes of this diachronity.

scholarly journals Lithofacies and depositional environment of the Siwalik Group in Samari-Sukaura River area, Central Nepal

2013 ◽  
Vol 16 ◽  
pp. 53-64 ◽  
Author(s):  
Dev Kumar Syangbo ◽  
Naresh Kazi Tamrakar
Keyword(s):  
Depositional Environment ◽  
Foreland Basin ◽  
River System ◽  
Nepal Himalaya ◽  
Meandering River ◽  
Fine Grained ◽  
Architectural Elements ◽  
Central Nepal ◽  
Eastern Zone ◽  
Siwalik Group

Thick sedimentary sequence deposited in the foreland basin of the Nepal Himalaya is represented by the Siwalik Group. The Siwalik Group is well exposed in the Samari-Sukaura River area. The present study is focused in southern portion of the MBT around the Samari-Sukaura area for its depositional environment. The Middle Siwaliks of the Sukaura Road sections is overlained by the Lower Siwaliks which is separated by the Karki Khola Thrust. Extension of the Lower Siwaliks in the Jyamire Khola and the Bundal Khola becomes wider in the eastern Zone. Repetition of the Lower Siwaliks along the southern margin of the MBT is recognized. Depending on lithofacies assemblage and facies analysis, the two broad facies assemblages FA1 and FA2 have been distinguished. FA1 shows SB, FF, LA, LS and CH architectural elements and is interpreted as a product of the fine-grained meandering river system. FA2 shows SB, FF, LA, DA and CH architectural elements and is interpreted as a product of sandy mixed-load meandering river system. DOI: http://dx.doi.org/10.3126/bdg.v16i0.8884   Bulletin of the Department of Geology Vol. 16, 2013, pp. 53-64

scholarly journals Formation and Changes of Multiple Sand Bars and Influence of Fine Sand Bed

1992 ◽  
Vol 36 ◽  
pp. 23-28
Author(s):  
Yuichiro FUJITA ◽  
Nobuhiro NAGATA ◽  
Yoshio MURAMOTO
Keyword(s):  
Fine Sand ◽  
Sand Bars

scholarly journals Interpretasi Lingkungan Pengendapan Formasi Batuan Menggunakan Analisis Elektrofasies di Lokasi Tapak Puspiptek Serpong

EKSPLORIUM ◽  
2017 ◽  
Vol 38 (1) ◽  
pp. 29
Author(s):  
Heri Syaeful ◽  
Adi Gunawan Muhammad
Keyword(s):  
Depositional Environment ◽  
Gamma Ray ◽  
River System ◽  
Shape Variation ◽  
Point Bar ◽  
Meandering River ◽  
The North ◽  
Rock Formations ◽  
Subsurface Material ◽  
Crevasse Splay

ABSTRAKKegiatan karakterisasi material bawah permukaan penyusun pondasi tapak merupakan bagian dari studi tapak instalasi nuklir. Karakterisasi dilakukan dengan berbagai metode, diantaranya pemahaman tentang sistem pengendapan formasi batuan. Sebagai bagian dari metode interpretasi lingkungan pengendapan, analisis pemodelan fasies berdasarkan elektrofasies memberikan informasi yang cepat mengenai sistem pengendapan suatu formasi batuan. Metodologi yang digunakan adalah dengan interpretrasi log sinar gamma (log GR) menggunakan korelasi relatif antara variasi bentuk log dan fasies sedimentasi. Berdasarkan analisis diketahui Formasi Bojongmanik terbentuk pada lingkungan marine-lagoonal dengan pengaruh gelombang sangat rendah. Log GR yang menunjukan bentuk funnel, bergerigi dan simetris, mengindikasikan fasies shoreface, lagoon, dan tidal point bar. Arah sedimentasi, cekungan, dan suplai pada pengendapan sedimen Formasi Bojongmanik diinterpretasikan relatif ke utara. Formasi Serpong diendapkan pada sistem sungai bermeander dan tersusun atas endapan point bar, crevasse splay dan floodplain. Hasil analisis ini diharapkan dapat menjadi panduan dalam analisis lanjutan terkait karakterisasi material pondasi. ABSTRACTThe activity of subsurface material composing site foundation characterization is part of nuclear installation siting study. Characterization conducted by several methods, such as understanding the depositional environment of rock formations. As a segment of depositional environment interpretation method, facies model analysis based on electrofacies provides quicker information on depositional system of rock formation. Methodology applied is gamma ray log (log GR) interpretation using relative correlation between log shape variation and sedimentation facies. Based on the analysis, Bojongmanik Formation was deposited on marine-lagoonal environment with very low wave influence. Log GR that shows shape of funnel, serrated, and symmetry, indicate shoreface, lagoon, and tidal point bar facies. The direction of sedimentation, basin, and supply of Bojongmanik Formation interpreted relatively to the north. Serpong Formation deposited on meandering river system, and composed of point bar deposit, crevasse splay, and floodplain deposit. The result of analysis is expected to be guidance in further analysis related to the characterization of foundation materials.

scholarly journals Development of a Numerical Model to Analyze the Formation and Development Process of River Mouth Bars

2021 ◽  
Vol 33 (6) ◽  
pp. 308-320
Author(s):  
Yeon-Joong Kim ◽  
Joung-Woon Woo ◽  
Jong-Sung Yoon ◽  
Myoung-Kyu Kim
Keyword(s):  
Formation Process ◽  
Numerical Models ◽  
Sediment Supply ◽  
Management Approach ◽  
Sediment Discharge ◽  
Duration Of Action ◽  
Sand Bars ◽  
Tidal Sand ◽  
Sand Bar ◽  
Bar Formation

An integrated sediment management approach that includes the recovery of the amount of declined sediment supply is effective as a fundamental solution to coastal erosion. During planning, it is essential to analyze the transfer mechanism of the sediments generated from estuaries (the junction between a river and sea) to assess the amount and rate of sediment discharge (from the river to sea) supplied back to the coast. Although numerical models that interpret the tidal sand bar flushing process during flooding have been studied, thus far, there has been no study focusing on the formation and development processes of tidal sand bars. Therefore, this study aims to construct wave deformation, flow regime calculation, and topographic change analysis models to assess the amount of recovered sediment discharge and reproduce the tidal sand bar formation process through numerical analysis for integrated littoral drift management. The tidal sand bar formation process was simulated, and the wave energy and duration of action concepts were implemented to predict the long-term littoral movement. The river flux and wave conditions during winter when tidal sand bars dominantly develop were considered as the external force conditions required for calculation. The initial condition of the topographic data directly after the Maeupcheon tidal sand bar flushing during flooding was set as the initial topography. Consequently, the tidal sand bar formation and development due to nearshore currents dependent on the incident wave direction were reproduced. Approximately 66 h after the initial topography, a sand bar formation was observed at the Maengbang estuary.

scholarly journals Can gravel augmentation restore thermal functions in gravel-bed rivers? A need to assess success within a trajectory-based BACI framework

2020 ◽  
Author(s):  
Baptiste Marteau ◽  
Kristell Michel ◽  
Hervé Piégay
Keyword(s):  
River System ◽  
Sediment Supply ◽  
Global Changes ◽  
Fundamental Parameter ◽  
Positive Feedbacks ◽  
Gravel Bed ◽  
Channel Adjustments ◽  
Gravel Bed Rivers ◽  
Term Monitoring

Gravel augmentation has become common practice to mitigate the effects of decline in upstream sediment supply in gravel-bed rivers. The success of such rehabilitation schemes relies partly on the monitoring strategy and efforts. When long-term monitoring is lacking, some aspects of rehabilitation initiatives suffer more than others, such as insights into functions and functionalities of the river system. Despite temperature being a fundamental parameter determining the general health of river ecosystems, a limited number of studies have tested whether gravel-augmentation can aid restoring thermal functions. With the help of airborne thermal infrared (TIR) imagery, this paper explores the potential positive feedbacks through the monitoring of gravel augmentation actions, of different magnitude, taken on 3 rivers of the Rhône basin in France. A specific trajectory-based Before-After-Control-Impact (BACI) framework using simple indicators, combined with a TIR-based Control-Impact strategy, was designed to assess the success of thermal function restorations based on dynamic fuzzy references. Results indicate that restoring forms is not sufficient to restore thermal functions. The control-impact strategy shows limitations in the sense that two neighbouring reaches can display similar planform characteristics but different thermal functions; what is observed in a control reach should not necessarily be expected following rehabilitation. When assessing thermal processes, a before-after strategy is needed to either serve as a target or help define an adequate target in accordance with changes in the catchment and channel adjustments and responsiveness. We therefore recommend a trajectory-based BACI assessment to identify current biogeophysical conditions within which rehabilitation can be assessed. From a technical perspective, airborne TIR proved to be useful to rapidly map surface temperature over dozens of kilometres at high resolution, and can be advocated as a powerful tool to monitor and diagnose thermal functions of gravel-bed rivers. With an increasing number of rehabilitation schemes, and increasing pressure of global changes on rivers, we suggest that monitoring of water temperature, even with simple but well-designed sampling strategies, becomes a routine part of river rehabilitation projects.

scholarly journals Million-year lag times in a post-orogenic sediment conveyor

2020 ◽  
Vol 6 (25) ◽  
pp. eaaz8845 ◽  
Author(s):  
R.-H. Fülöp ◽  
A. T. Codilean ◽  
K. M. Wilcken ◽  
T. J. Cohen ◽  
D. Fink ◽  
...  
Keyword(s):  
River Sediment ◽  
River System ◽  
Sediment Supply ◽  
Environmental Forcing ◽  
Murray Darling Basin ◽  
Transit Times ◽  
Lag Times ◽  
Geologic Record ◽  
And Storage ◽  
Multiple Episodes

Understanding how sediment transport and storage will delay, attenuate, and even erase the erosional signal of tectonic and climatic forcings has bearing on our ability to read and interpret the geologic record effectively. Here, we estimate sediment transit times in Australia’s largest river system, the Murray-Darling basin, by measuring downstream changes in cosmogenic 26Al/10Be/14C ratios in modern river sediment. Results show that the sediments have experienced multiple episodes of burial and reexposure, with cumulative lag times exceeding 1 Ma in the downstream reaches of the Murray and Darling rivers. Combined with low sediment supply rates and old sediment blanketing the landscape, we posit that sediment recycling in the Murray-Darling is an important and ongoing process that will substantially delay and alter signals of external environmental forcing transmitted from the sediment’s hinterland.

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