scholarly journals Did the Construction of the Bhumibol Dam Cause a Dramatic Reduction in Sediment Supply to the Chao Phraya River?

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 386
Author(s):  
Matharit Namsai ◽  
Warit Charoenlerkthawin ◽  
Supakorn Sirapojanakul ◽  
William C. Burnett ◽  
Butsawan Bidorn
Keyword(s):  
Saltwater Intrusion ◽  
River System ◽  
Sediment Supply ◽  
Sediment Flux ◽  
Hydroelectric Power ◽  
Chao Phraya River ◽  
The Impact ◽  
Total Sediment ◽  
Hydroelectric Power Generation

The Bhumibol Dam on Ping River, Thailand, was constructed in 1964 to provide water for irrigation, hydroelectric power generation, flood mitigation, fisheries, and saltwater intrusion control to the Great Chao Phraya River basin. Many studies, carried out near the basin outlet, have suggested that the dam impounds significant sediment, resulting in shoreline retreat of the Chao Phraya Delta. In this study, the impact of damming on the sediment regime is analyzed through the sediment variation along the Ping River. The results show that the Ping River drains a mountainous region, with sediment mainly transported in suspension in the upper and middle reaches. By contrast, sediment is mostly transported as bedload in the lower basin. Variation of long-term total sediment flux data suggests that, while the Bhumibol Dam does effectively trap sediment, there was only a 5% reduction in sediment supply to the Chao Phraya River system because of sediment additions downstream.

scholarly journals Impact of sediment–seawater cation exchange on Himalayan chemical weathering fluxes

2016 ◽  
Vol 4 (3) ◽  
pp. 675-684 ◽  
Author(s):  
Maarten Lupker ◽  
Christian France-Lanord ◽  
Bruno Lartiges
Keyword(s):  
Cation Exchange ◽  
Chemical Weathering ◽  
Sediment Load ◽  
Relative Proportion ◽  
River System ◽  
Exchange Capacity ◽  
Sediment Flux ◽  
Continental Scale ◽  
The Impact

Abstract. Continental-scale chemical weathering budgets are commonly assessed based on the flux of dissolved elements carried by large rivers to the oceans. However, the interaction between sediments and seawater in estuaries can lead to additional cation exchange fluxes that have been very poorly constrained so far. We constrained the magnitude of cation exchange fluxes from the Ganga–Brahmaputra river system based on cation exchange capacity (CEC) measurements of riverine sediments. CEC values of sediments are variable throughout the river water column as a result of hydrological sorting of minerals with depth that control grain sizes and surface area. The average CEC of the integrated sediment load of the Ganga–Brahmaputra is estimated ca. 6.5 meq 100 g−1. The cationic charge of sediments in the river is dominated by bivalent ions Ca2+ (76 %) and Mg2+ (16 %) followed by monovalent K+ (6 %) and Na+ (2 %), and the relative proportion of these ions is constant among all samples and both rivers. Assuming a total exchange of exchangeable Ca2+ for marine Na+ yields a maximal additional Ca2+ flux of 28  ×  109 mol yr−1 of calcium to the ocean, which represents an increase of ca. 6 % of the actual river dissolved Ca2+ flux. In the more likely event that only a fraction of the adsorbed riverine Ca2+ is exchanged, not only for marine Na+ but also Mg2+ and K+, estuarine cation exchange for the Ganga–Brahmaputra is responsible for an additional Ca2+ flux of 23  ×  109 mol yr−1, while ca. 27  ×  109 mol yr−1 of Na+, 8  ×  109 mol yr−1 of Mg2+ and 4  ×  109 mol yr−1 of K+ are re-absorbed in the estuaries. This represents an additional riverine Ca2+ flux to the ocean of 5 % compared to the measured dissolved flux. About 15 % of the dissolved Na+ flux, 8 % of the dissolved K+ flux and 4 % of the Mg2+ are reabsorbed by the sediments in the estuaries. The impact of estuarine sediment–seawater cation exchange appears to be limited when evaluated in the context of the long-term carbon cycle and its main effect is the sequestration of a significant fraction of the riverine Na flux to the oceans. The limited exchange fluxes of the Ganga–Brahmaputra relate to the lower than average CEC of its sediment load that do not counterbalance the high sediment flux to the oceans. This can be attributed to the nature of Himalayan river sediment such as low proportion of clays and organic matter.

scholarly journals Effects of Dam Construction in the Wang River on Sediment Regimes in the Chao Phraya River Basin

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2146
Author(s):  
Warit Charoenlerkthawin ◽  
Matharit Namsai ◽  
Komkrit Bidorn ◽  
Chaipant Rukvichai ◽  
Balamurugan Panneerselvam ◽  
...  
Keyword(s):  
River Basin ◽  
River Flow ◽  
Sediment Load ◽  
Annual Runoff ◽  
Sediment Supply ◽  
Dam Construction ◽  
Average Annual Runoff ◽  
Chao Phraya River ◽  
The Impact ◽  
Total Sediment

The Wang River is one of the major tributaries of the Chao Phraya River (CPR) system in Thailand as the key riverine sediment source supplying the Chao Phraya Delta that has experienced severe shoreline retreat in the past six decades. Historical and observed river flow and sediment data measured during 1929–2019 were used to assess the variation in total sediment load along the Wang River and evaluate the effects of three major dam constructions on sediment supplied from the Wang River to the CPR. Results indicated that sediment loads increased toward downstream. Variation in long-term total sediment load (TSL) along the river suggested that construction of the Kiew Lom Dam in 1972 did not cause a reduction in sediment yield in the Wang River Basin because it impounded less than 20% of the average annual runoff, while the Mae Chang and Kiew Koh Ma Dams caused downstream sediment reduction. These three dams are located in the upper and middle river basins, and their effects on sediment load in the Wang River are ameliorated by additional sediment supplied from the lower basin. Results confirmed that construction of these three major dams in the Wang River did not greatly impact sediment supply from the Wang River to the CPR system. The dam site and sediment load variation along the river are the primary factors controlling the impact of the dam construction.

scholarly journals Stratigraphy of the Anthropocene

2011 ◽  
Vol 369 (1938) ◽  
pp. 1036-1055 ◽  
Author(s):  
Jan Zalasiewicz ◽  
Mark Williams ◽  
Richard Fortey ◽  
Alan Smith ◽  
Tiffany L. Barry ◽  
...  
Keyword(s):  
Sediment Flux ◽  
Relative Timing ◽  
Sequence Stratigraphic ◽  
The Earth ◽  
Time Space ◽  
Marine Realm ◽  
Physical And Chemical ◽  
The Impact ◽  
Long Term Preservation

The Anthropocene, an informal term used to signal the impact of collective human activity on biological, physical and chemical processes on the Earth system, is assessed using stratigraphic criteria. It is complex in time, space and process, and may be considered in terms of the scale, relative timing, duration and novelty of its various phenomena. The lithostratigraphic signal includes both direct components, such as urban constructions and man-made deposits, and indirect ones, such as sediment flux changes. Already widespread, these are producing a significant ‘event layer’, locally with considerable long-term preservation potential. Chemostratigraphic signals include new organic compounds, but are likely to be dominated by the effects of CO 2 release, particularly via acidification in the marine realm, and man-made radionuclides. The sequence stratigraphic signal is negligible to date, but may become geologically significant over centennial/millennial time scales. The rapidly growing biostratigraphic signal includes geologically novel aspects (the scale of globally transferred species) and geologically will have permanent effects.

scholarly journals Bedrock incision by bedload: insights from direct numerical simulations

2016 ◽  
Author(s):  
Guilhem Aubert ◽  
Vincent J. Langlois ◽  
Pascal Allemand
Keyword(s):  
Numerical Approach ◽  
Sediment Supply ◽  
Sediment Flux ◽  
Analytical Models ◽  
Water Stream ◽  
Direct Measurements ◽  
Bedload Sediment ◽  
Discrete Element Simulations ◽  
High Sediment

Abstract. Bedload sediment transport is one of the main processes that contribute to bedrock incision in a river and is therefore one of the key control parameters in the evolution of mountainous lanscapes. In recent years, many studies have addressed this issue through experimental setups, direct measurements in the field or various analytical models. In this article, we present a new direct numerical approach: using the classical methods of discrete element simulations applied to granular materials, we compute explicitely the trajectories of a number of pebbles entrained by a turbulent water stream over a rough solid surface. This method allows us to extract quantitatively the amount of energy that successive impacts of pebbles deliver to the bedrock, as a function of both the amount of sediment available and the Shields number. We show that we reproduce qualitatively the behaviour observed experimentally by Sklar and Dietrich (2001) and observe both a "tool-effect" and a "cover- effect". Converting the energy delivered to the bedrock into an average long-term incision rate of the river leads to predictions consistent with observations in the field. Finally, we reformulate the dependency of this incision rate with Shields number and sediment flux, and predict that the cover term should decay linearly at low sediment supply and exponentially at high sediment supply.

Recognising tectonic and climatic signals in the Paleogene stratigraphy offshore Norway

2020 ◽  
Author(s):  
Tor O. Sømme ◽  
Jakob Skogseid ◽  
Patricia Embry ◽  
Helge Løseth
Keyword(s):  
Seismic Data ◽  
Supply System ◽  
Sediment Supply ◽  
Sediment Flux ◽  
Similar Process ◽  
System Response ◽  
Seismic Reflection Data ◽  
Shelf Slope ◽  
Depositional System

<p>Landscapes and their sediment routing systems can be exposed to various tectonic and climatic perturbations that affect sediment production, transport and delivery to nearby sedimentary basins. Here we investigate a Paleogene depositional system offshore western Norway that was subjected to long-term (~10 Myr) tectonic perturbation and significant hinterland erosion. Superimposed on this long-term uplift, the system was also subjected to a short-lived climatic perturbation during the Paleocene-Eocene Thermal Maximum (PETM), which lasted ~200 kyr. Regional 3D seismic reflection data is integrated with high resolution well data to map the stratigraphic response to these different scales of perturbations on the depositional system. The initiation of the tectonic perturbation is marked by an angular unconformity in seismic data. A rapid increase in sediment flux followed, causing initial progradation of a shelf-slope wedge. Sediment supply estimates indicate that the tectonic uplift caused an order of magnitude increase in sediment flux to the basin, which peaked in the latest Paleocene. This period coincided with the PETM, which is documented by biostratigraphic data as a discrete event within the overall regressive system. Although the PETM often is characterised by increased continental runoff, no increase in sediment supply is evident from seismic data. This work shows that the system response to tectonic and climatic perturbations may vary along strike, depending on the size of the routing systems and the antecedent topography prior to hinterland uplift. A low supply system may produce a tectonically-linked shelf-slope wedge that is of similar thickness as a climatically-linked wedge in a high supply system. This study documents how the same routing system responded to perturbations operating at different spatial and temporal scales and may help recognise similar process-response relationships in other areas.</p>

scholarly journals The Amur River Water During the Winter Low-water Period: The Many-year dynamics of the Sulfates Content and Runoff.

2020 ◽  
pp. 82-93
Author(s):  
Keyword(s):  
Power Plants ◽  
Hydroelectric Power ◽  
Amur Basin ◽  
Amur River ◽  
Economic Changes ◽  
Large Cities ◽  
The Amur River ◽  
The Many ◽  
The Impact

ulfates are the dominant ions among the major ones in the Amur region’s sewage. Therefore, the purpose of the research is to study the long-term dynamics of the content and runoff of sulfates in the Amur River in the winter low-water, based on the materials of Roshydromet for 1943-1976 and the author’s data for 1999-2019.Significant variations in the main areas were found due to both the diversity of natural conditions and anthropogenic influence in the areas of large cities and localities. The impact of the construction of hydroelectric power plants, significant economic changes in the Chinese part of the Amur basin, as well as the closure of pulp and paper and microbiological industries in the Russian part of the Amur basin on the long-term dynamics of the content and flow of sulfates is estimated. The maximum content of sulfates in the Amur River was observed after the accident at the Jilin chemical plant in China in December 2005. The influence of major floods on the increase in the flow of sulphates in the winter low-water was established.

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 Mathematical model in assesment of saltwater intrusion in Saigon – Dong Nai river system (Southern Vietnam) due to sea level rise

2014 ◽  
Vol 17 (3) ◽  
pp. 94-102 ◽  
Author(s):  
Thong Chi Ho ◽  
Ngo Van Dau ◽  
Giang Song Le ◽  
Oanh Thi Phi Tran
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Saltwater Intrusion ◽  
River System ◽  
Vital Role ◽  
Ho Chi Minh City ◽  
Regulatory Regime ◽  
Water Regulation ◽  
Before And After ◽  
The Impact

SaiGon –DongNai (SG-DN) river system plays a vital role in developing the southern key economic triangle including Ho Chi Minh City, DongNai and BinhDuong provinces. Saltwater intrusion results from many factors and complex movements in SG–DN river system, in the midst of which are sea level rise and water regulation of upstream reservoirs. Theses causes have gradually changed the hydraulic regimes of the river system. As a result, saltwater intrusion has become seriously. In this article, the authors used mathematical models to investigate the change of saltwater boundary of the river system before and after the impact of sea level rise and the regulatory regime of the reservoirs. The findings contributed to the predicted scenarios where sea level rise and salinity boundary could be controlled through the regulation of upstream reservoirs.

Width control on event scale bedload dynamics in bedrock-confined channels

2021 ◽  
Author(s):  
Kristen Cook ◽  
Jens Turowski ◽  
Niels Hovius
Keyword(s):  
Random Sequence ◽  
Bedload Transport ◽  
Sediment Supply ◽  
Sediment Flux ◽  
Channel Width ◽  
Sediment Grain Size ◽  
Event Scale ◽  
Narrow Channels ◽  
Coarse Sediment ◽  
The Impact

<p>In mixed bedrock-alluvial rivers, the response of the system to a flood event can be affected by a number of factors, including coarse sediment availability in the channel, sediment supply from the hillslopes and upstream, flood sequencing, and coarse sediment grain size distribution. However, the impact of along-stream changes in channel width on bedload transport dynamics remains largely unexplored. We combine field data, theory, and numerical modeling to address this gap. Observations from two flood events in the Daan River gorge in western Taiwan suggest that coarse sediment evacuation and re-deposition can cause intra-flood changes of up to several meters in channel bed elevation that are distinct from measured before/after bed changes. We hypothesize that this could be related to the abrupt change in width between the 1 km long bedrock gorge and the river upstream and downstream. An analysis of the theoretical relationships between discharge, channel width, and bedload transport capacity shows that for a given slope, narrow channels transport bedload more efficiently than wide ones at low discharges, while wider channels are more efficient at high discharges. We used the model sedFlow to explore this effect, running a random sequence of floods through a channel with a narrow gorge section bounded upstream and downstream by wider reaches. Channel response to imposed floods is complex, as high and low discharges drive different spatial patterns of erosion and deposition, and the channel may experience both of these regimes during the peak and recession periods of each flood. Our modeling suggests that width differences alone can drive substantial variations in sediment flux and bed response, without the need for variations in sediment supply or mobility. Further, the deposition or erosion that takes place within a flood is often not reflected in the before/after changes to the bed, and this disconnect increases with increasing flood size.</p>

scholarly journals Appraising the Impact of Naraj Barrage on Sedimentation of Chilika Lagoon; the Soft Computing Model for Prediction

2020 ◽  
pp. 31-41
Author(s):  
Siba Prasad Mishra ◽  
Ananta Charan Ojha
Keyword(s):  
Sediment Transport ◽  
Suspended Sediment ◽  
Learning Algorithm ◽  
River System ◽  
Suspended Sediment Transport ◽  
Chilika Lagoon ◽  
Surrounding Environment ◽  
Ensemble Machine Learning ◽  
The Impact ◽  
Total Sediment

Estimation of suspended sediment transport in a catchment area is very important to manage water resources, construction of dam and barrage, as well as to protect the surrounding environment. The daily monsoon sediment and flow were observed physically and quantity of total sediment input by the two major rivers of the south Mahanadi deltaic rivers to Lagoon Chilika were calculated during pre Naraj barrage (FY 2000 to 2003) and post Naraj Barrage period (FY’s 2004, 2012, 2013) establishing an observatory in the rivers the Daya and the Bhargovi.[b] The non-linear complex relationship between quantity of suspended sediment transport and volume of river-discharge inflicts challenge to the estimation process. In this paper, two southern-most distributaries, the Daya and the Bhargovi of the Mahanadi River System which flow into Chilika lagoon are studied. Random Forest, an ensemble machine learning algorithm is used to estimate the transport of sediment by these two distributaries using predictive modeling. Predicted figures based on the gathered data from these distributaries during pre-barrage period 2000-2003 have been compared with the observed data gathered in post-barrage years 2004, 2012 and 2013. Comparative data suggests that the construction of Naraj barrage has significantly reduced the concentration of sediment influx into Chilika lagoon while controlling the discharge through effective barrage management.

Sign in / Sign up

Export Citation Format

Share Document