74 research outputs found
Stuw in de Jamuna, Bangladesh: Stuwcomplex op de lokatie "Jamuna-brug" nabij Sirajganj
No full textDoel van dit projekt is het aanwijzen van een lokatie voor het bouwen van een stuwcomplex, waama er een ontwerp voor de stuw wordt gemaakt en er wordt gekeken naar een manier om de bouw van het stuwcomplex uit te voeren. Tevens wordt aandacht besteed aan het opwekken van energie door middel van een energiecentrale. In het afstudeerrapport van W.J.M.Lamers (1994) zijn een aantal mogelijke lokaties voor de bouw van een stuwcomplex bestudeerd. Hierin wordt geconcludeerd dat de lokaties Madarganj en Bera het meest geschikt zijn voor de bouw van h.et stuwcomplex. In dit rapport is de lokatie Sirajganj, ter plaatse van de in aanbouw zijnde geleidedammen voor de Jamuna-brug, als derde mogelijke lokatie bestudeerd. De lokaties "Jamuna-brug" bij Sirajganj, Madarganj en Bera hebben elk hun voor- en nadelen, maar het grote voordeel van de lokatie bij de Jamuna-brug is dat het dwarsprofiel van de rivier de Jamuna al voor een belangrijk deel is vastgelegd door de geleidedammen, zodat een stabiele lokatie voor de bouw van een stuwcomplex min of meer gegarandeerd is. Het vinden van een lokatie, daar waar de rivier de Jamuna een stabiele ligging heeft, is een van de belangrijkste problemen bij het aanwijzen van een geschikte lokatie voor de bouw van een stuwcomplex. De stabiele lokatie ter plaatse van de Jamuna-brug is van dusdanig grote invloed dat gekozen is voor het situeren van het stuwcomplex bij "lokatie Jamuna-brug", Sirajganj.Hydraulic EngineeringCivil Engineering and Geoscience
Jamuna bridge project river works
No full textIn this part of the graduation report concerning the Jamuna Bridge Project in Bangla Desh, the main issues are the following : - An elaborate inventarisation of parameters and qualities of the Jamuna River system which are of consequence for the design concept of the river training works as weIl as the bridge itself. In this context special attention is given to the stability of the river in the past and the prediction of water- and bedlevels. - The development of a design philosophy and criterium for the lay-out of the bridge works. In this respect the length of the required training works versus the bridge length is of essential importance. - The determination of the principal design criteria for the structural design of the river training works. The aim of this part of the study is to arrive at a first configuration of the required training works. Due to the limited time span it was not possible to refine the configuration, i.e. a reconsideration of assumptions, starting points and design criteria as the scheme in appendix I suggests. In fact it is this scheme which has been run through one time. Also this report does not pretend to give a complete elaboration of all factors concerning the design of training works. It is therefore often only indicated that certain factors should be included in the design process possibly leading to another solution.Hydraulic EngineeringCivil Engineering and Geoscience
Jamuna Bridge Project: Mitigatory measures on the closure of the Dhaleswari River
No full textIn Bangladesh a bridge is designed over one of wortd's largest braiding rivers: the Jamuna River. In the floodplain a river, the Dhaleswari River, originates from the Jamuna River by several intake channels. The eastern bridge approach will close one off the main intake channels. Goal of the study was: - Determinè the effect of the closure on the downstream area - Design some mitigatory measures on the closureHydraulic EngineeringCivil Engineering and Geoscience
Stuw in de Jamuna, Bangladesh
No full textIn Bangladesh moet de voedselproduktie worden vergroot. Met een bevolkingsdichtheid van rond de 760 inwoners per vierkante kilometer is Bangladesh een dichtbevolkt land. De bevolking is in de afgelopen decennia fors gegroeid en deze groei duurt voort. De voedselproduktie heeft de bevolkingsgroei niet bij kunnen houden. Om Bangladesh zelfvoorzienend te maken moet de voedselproduktie daarom flink opgevoerd worden. Een van de mogelijkheden om dit te doen is de aanleg van een grootschalig irrigatiesysteem. Dit kan gedaan worden door in de rivier de Jamuna een stuw te bouwen die in de droge tijd het water opstuwt en tijdens hoogwater wordt gestreken. Er is dan in de droge tijd meer water beschikbaar en door de hogere waterstand is het maken van inlaatwerken voor irrigatiewater eenvoudiger. Doel van dit project is het uitvoeren van een voorstudie voor de bouw van een dergelijke stuw. Behalve voor het vormen van een reservoir voor irrigatiewater kan de stuw gebruikt worden voor andere doeleinden. Met name energieopwekking is een reële optie, omdat de afvoer in de Jamuna altijd groter is dan de voor irrigatie noodzakelijke aftap. Eerst is uitgezocht welke stuwhoogte kan worden toegepast en hoe lang de fase van stuwen moet duren. Van invloed zijn daarop de behoefte aan irrigatiewater, de afmetingen van het reservoir, de gevolgen van sedimentatie en de te behalen energieopbrengst bij toepassen van waterkracht. Dit afstudeerwerk is een voorstudie naar een Stuw. Hierbij zijn de gegevens van de rivier, behoefte aan irrigatiewater, afmetingen van het reservoir, gevolgen van sedimentatie, stuwpeil en beheer van het reservoir, mogelijke locaties, indeling van het stuwcomplex en uitvoering meegenomen.WaterbouwHydraulic EngineeringCivil Engineering and Geoscience
Taming the Jamuna: Effects of river training in Bangladesh
No full textThe 10 km wide Jamuna river in Bangladesh is one of the most morphologically active rivers in the world, with bank erosion rates of up to 500 m per year (Mutton and Haque 2004). Such extreme river migration in the center of Bangladesh, one of the most densely populated and impoverished regions in the world, displaces roughly 60,000 people per year (Mutton and Haque 2004). To alleviate this, the Government of Bangladesh has committed to stabilizing and narrowing it’s major rivers with the Flood and Riverbank Erosion Risk Management Investment Program (FRERMIP) (ADB 2016). FRERMIP is investigating numerous training scenarios and final stabilized widths (4-8 km). These scenarios are combinations of works (spur dikes, dredging) at different locations and activation rates (i.e. construction schedules) which FRERMIP seeks to optimize for cost, navigation, bank erosion prevention and flood mitigation. However, little is understood about how these proposals may affect the sediment balances in Bangladesh. The Jamuna combines with the Ganges and Upper Meghna to form the world’s second largest delta: the Bengal delta. Due to the high sediment load delivered from these Himalayan rivers, accretion rates in the delta have been in the order of 5 km2/yr (Sarker et al. 2011). Changes in the supplied sediment to the delta may reduce this accretion, amplifying the consequences of sea level rise. A better understanding of how proposed trainings will affect the sediment supply to the delta can help decision makers weigh the pros and cons of implementation, and prepare for these impacts on the delta. </p
Stabilization of the Lower Jamuna River in Bangladesh: Hydraulic and Morphological Assessment
No full textThis paper presents a hydraulic and morphological analysis of the Lower Jamuna in Bangladesh with a focus on two key bifurcations that are important for stabilization of the Lower Jamuna reach. We used ground measurements, historical data, multispectral satellite images from various sources as well as numerical models. We carried out hydraulic analyses of the changes and their peculiarities, such as flow distributions at the bifurcation and hysteresis of the stage–discharge relationships. We supplemented our analysis by using numerical models to simulate discharge distribution at the bifurcations under various flow and riverbed conditions. We developed an advanced and automated satellite image processing application for the Lower Jamuna, referred to as Morphology Monitor (MoMo), using the Google Earth Engine. MoMo was found to be an effective tool for a rapid assessment and analysis of the changes in deep-channel and sandbar areas. It is also useful for monitoring and assessing riverbank and char erosion and accretion, which is important not only for morphological but also ecological impact assessment. The application can be adapted as an operational tool as well. Furthermore, we assessed the evolution of deep channels at the bifurcations based on regularly and extensively measured bathymetry data. The analysis was carried out in complement with morphological modeling, particularly for short-term prediction. In this paper we present the major findings of the analysis and discuss their implications for adaptive river management.Rivers, Ports, Waterways and Dredging Engineerin
Performance review of Jamuna Bridge River Training Works 1997-2009
No full textRecently a review was made of the performance of the Jamuna Bridge River Training Works (RTW), crossing the braided Brahmaputra River in Bangladesh. The RTW are functioning since 1997. The review was carried out to identify any improvements which could possibly be made both in the design proper and in the supporting studies for forthcoming bridge projects. In the review period of 13 years, the RTW were not fully tested, as during none of the years was the design discharge approached or was the upstream channel pattern characterized by extreme outflanking. Although the yearly maintenance required until 2009 is on the average only 0.13% of the capital costs of the RTW, still some unexpected phenomena were observed. The design scour depths were exceeded substantially, and scour holes of almost 45 m below average flood levels were observed. The scour occurs during outflanking and additional studies are needed to understand the cause and possible remedies. Locally substantial shifting of the rock of the slope protection is observed, leaving the underlying geotextile exposed. Regular inspection and maintenance as specified is needed to keep the RTW in optimal condition
The Jamuna-Brahmaputra River, Bangladesh
No full textBangladesh is dominated by three great rivers – the Jamuna-Brahmaputra, Ganga and Meghna – that combine to feed sediment into one of the World’s largest deltas in the Bay of Bengal (Figure 21.1). Bangladesh has been shaped by, and is dependent upon, its rivers, which provide fertile soils and a diverse flora and aquaculture but also bring significant flood hazard and risk to infrastructure for a large and growing population. Current anthropogenic stresses, in terms of changing climate, water diversions, pollution and sediment extraction, are posing new pressures to the river and its inhabitants (Best, 2019). The people of Bangladesh have adapted their lifestyle for centuries to live with river flooding – frequently moving their temporary bankside homes, planting on newly emergent river bars, and sometimes raising their homesteads above water level in flood periods (Paul, 1997). However, a growing population, coupled with the expansion of infrastructure and economic development, has resulted in an increase in the intensity of flood damage (FPCO, 1995; Paul, 1997; CPD, 2004). The lives of many millions of Bangladeshi citizens are reliant on these rivers, with up to 2.3 million people living on the riverine islands alone (Schmuk-Widmann, 2001). Bangladesh’s rural economy relies upon annual ‘normal’ floods to bring moisture and fresh sediments to the floodplain soils (Paul, 1997): for instance, two of the three seasonal rice varieties (aus and aman) cannot survive without floodwater and the fish caught both on the floodplain during flood season and from the many floodplain ponds (‘beels’) provide the main source of protein for many rural populations (Chowdhury, 1994; Paul, 1997; de Graff, 2003; Shankar et al., 2004). However, the effect of ‘abnormal’ floods can be devastating and result in appreciable damage to crops and houses, severe bank erosion with consequent loss of homesteads, schools and land, and loss of human lives, livestock and fisheries (BDER, 2004; Shankar et al., 2004). For example, in the 1998 flood, over 70 % of the land area of Bangladesh was inundated, affecting 31 million people and 1 million homesteads (Chowdhury, 2000). The 1998 flood, which had an unusually long duration from July to September, claimed 918 human lives and was responsible for damaging 16 000 and 6000 km of roads and embankments, respectively, and affecting 6000 km2 of standing crops (Chowdhury, 2000). In the 2004 floods, over 25 % of the population of Bangladesh, or 36 million people, was affected by the floods; 800 lives were lost; 952 000 houses were destroyed and 1.4 million badly damaged; 24 000 educational institutions were affected, including the destruction of 1200 primary schools; 2 million government and private tubewells were affected, and over 3 million latrines were damaged or washed away, this increasing the risks of diarrhoea, cholera and other waterborne diseases. Also, 1.1 million ha of rice crop was submerged and lost before it could be harvested, with 7 % of the yearly aus (early season) rice crop lost; 270 000 ha of grazing land was affected, 5600 livestock perished together with 254 000 poultry and 63 Mt of lost fish production (BDER, 2004; CPD, 2004). In the districts that are dominated by the Brahmaputra-Jamuna River, the 2004 flood damage to infrastructure (homes, roads, culverts), tubewells and latrines, with ensuing unemployment of many of the population, were some of the areas of critical impact. The total cost of the damage caused by the 2004 flood is estimated at $7 billion (CPD, 2004)
Bioavailability of Iron and Zinc from Soya Protein Matrix
No full textThis Dissertation / Report is the outcome of investigation carried out by the creator(s) / author(s) at the department/division of Central Food Technological Research Institute (CFTRI), Mysore mentioned below in this page
Development of the first spill channel after the Dhaleswari closure
No full textIn Bangladesh a bridge is under construction over the Jamuna River, one of world's largest braiding rivers. The Dhaleswari river system is fed by the Jamuna through smaller rivers, called spill channels, because they only carry discharge during the monsoon. One of the functions of the northern Dhaleswari offtake is the supply of water to the Compartmentalization Pilot Project, which is located downstream. In autumn 1994 this offtake was closed, because of construction of the reclamation of the eastern bridge approach. Therefore the Dhaleswari Committee made a design for a substitute link channel. But during the monsoon of 1995 the First Spill Channel, which used to be a very small channel situated immediately south of the Jamuna Bridge site, developed to the size of the northern Dhaleswari intake. So the main topic of this study is: should the First Spill Channel remain open or should the plans be executed for the proposed link channel more to the south? In order to answer this question the following issues are relevant. (1) Can the First Spill Channel replace the discharge of the former northern intake? (2) Is it necessary to take action against the meandering behavior of the First Spill Channel in order to protect the Jamuna Bridge site? If so, what measures should be taken? For a start a detailed description, based on regular observation, survey and a theoretical analysis of the development of the spill channel, is done. This information is used for making a hydrodynamical and a morphological computer model. After comparing the results of the hydrodynamical model for the situation of before the closure with a model of the new situation, it can be concluded that the discharge into the Dhaleswarl river system will be restored. From the morphological model it can be concluded that the spill channel can either be subjected to erosion or siltation in the future, because the model is very sensitive to the sediment inflow from the Jamuna, which depends strongly on the morphological situation in the Jamuna in front of the entrance. Moreover, this situation is changing rapidly, because of the bridge building activities. Therefore this aspect is also included in the study. The computer models are restricted to one-dimensional changes, while it appeared that the bank erosion plays a significant role. Therefore a separate study is done on the meandering of the spill channel bends, the entrance and in particular the sediment distribution at this bifurcation point. On the long-term the spill channel can certainly endanger the southern embankment of the site and the approach road for the bridge. Meanwhile maintenance of the discharge through the First Spill Channel is of importance for the CPP. Therefore some suggestions are done which minimize the probability of siltation and reduce the meander development of the First Spill Channel. It appears that a short~term solution can be found in a new design of the entrance and for the long-term protection of the southern embankment of the reclamation and the approach road is probably necessary.Hydraulic EngineeringCivil Engineering and Geoscience
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