River engineering

About: River engineering is a research topic. Over the lifetime, 435 publications have been published within this topic receiving 10286 citations. The topic is also known as: Channelisation.

Three-dimensional mathematical model and its application in the neighborhood of the Three Gorges Reservoir dam in the Yangtze River

Abstract: The calculation of flow and sediment transport is one of the most important tasks in river engineering. The task is particularly difficult because a number of complex physical phenomena should be accounted for more realistically in a model with a predictive power. Three-dimensional calculations of river flow and suspended sediment transport are performed in this paper with application in the Three Gorges Reservoir in the Yangtze River. A period of 76 years after the dam is built is simulated and the results are compared with laboratory measurements obtained by Tsinghua University whereby the model is verified and calibrated. Generally speaking, the calculated results agree well with the experiments, demonstrating that the present model can be used for flow and sediment transport prediction in rivers.

Impacts of River Engineering on Multi-Decadal Water Discharge of the Mega-Changjiang River

Abstract: Knowledge of river engineering impacts on water discharge is significant to flow guidelines and sustainable water resource managements for balancing human consumption and the natural environment. In this study, based on the collected multi-decadal discharge data at Yichang, Hankou, and Datong stations, we determined that in October, Three Gorges Dam contributed 34.4%, 24.5%, and 18.7% to the discharge decrease in the upper, middle, and lower reach, respectively, while Gezhouba Dam contributed 14.5%, 10.7%, and 10%. Danjiangkou Reservoir caused the discharge ratio of Hanjiang to Changjiang to decline from 7.2% during 1954–1973 to 6.3% during 1973–2014. Owing to growing water withdrawal and consumption, we suggest that the distribution of water diversion and consumption should be regulated to prevent the probable occurrence of the severe issue of salt water intrusion in the Changjiang Estuary in 2028.

From asset to threat: trajectory of sediment on the Rhône River

Abstract: Sediment is physical matter and, as such, is usually studied in the physical and natural sciences, such as chemistry, geomorphology, or hydraulics and hydrology. However, sediment is also deeply embedded in society and politics. Sediment flows are affected by river transformation and, in turn, affect river management. This article highlights the changing ways in which society has considered sediment in the Rhone River (France). In the early-modern historical period (16th–18th c.) sediment was generally considered a blessing. However, the contemporary evolution of the Rhone’s industrialisation, river engineering, and governance has challenged this perspective. Today sediment is more likely to be viewed as a threat. The concept of the hydrosocial cycle is a useful framework within which to describe the variety of ways societies have understood river sediment. The variation is caused by, and in turn affects, the meaning and representation of sediment, the structure of land and water governance, the nature of sedimentary and water resources, and the materiality of sediment and water, mediated by technology. This article aims to open the issue of sediment to the social sciences through a dialogue between history, human geography, and political science.

Design Development and Field Application of RCC Jack Jetty and Trail Dykes for River Training

Abstract: While river training structures are important tools to provide solutions to river engineering problems, conventional structures can be expensive and can create adverse environmental impacts. There is a need to develop affordable permeable river training structures. Jack jetties have been in use in the USA for various purposes, although there was no scientific methodology to support design of the structures when used for river training works. Therefore, laboratory studies have been carried out to develop this design methodology, which was verified by field-testing. Trail dykes were also tested in a similar fashion. Both types of structures show promise for use as inexpensive river engineering works.

Dilution Method for Measurements of Unsteady Discharges in Mountain Streams

Abstract: In river engineering problems information on discharges and water levels is essential for many reasons. For irrigation and drinking water purposes it is very important to know how much water can be extracted from a river. Managers of waste water stations need to know how much they can release without exceeding the norms, and information on flood waves in the past help to predict the probability of flood waves in the future. Discharge measurements are therefore necessary. Different methods to measure a river discharge exist, such as the velocity area method, the moving boat method and methods using structures like flumes and weirs. Another method is the dilution method, based on the dilution of a soluble, non-disintegrating substance, to be released in the river. For steady flows, the principles of this method are rather simple, and recommendations on how to perform the measurements already exist (ISO Handbook). However, for unsteady flows, this method is much more complicated, and even its applicability is questionable. Studies on this topic, in which rivers were schematised as prismatic channels have already been carried out. In the present study the practice is the central issue. The applicability of the dilution method is investigated for mountain rivers with irregular cross-sections, big rocks and unsteady discharges. In chapter 2 the principles of the dilution method are explained, and the studies made thus far are outlined, as well as the approach in the present study. In chapter 3 the basic equations for the motion of water and transport processes, necessary for a transport model that can deal with the typical problems of an irregularly shaped mountain river, are formulated. A numerical scheme is derived in chapter 4, resulting into a flow-and-transport-simulating computer program (FATS). Dilution discharge measurements are simulated in imaginary rivers under flood wave conditions . The river discharge is then a time dependent upstream boundary condition, and a few measurements (water levels, concentrations) are generated. In chapter 5 a numerical procedure is developed (FINDQ) to compute the upstream river discharge, which uses only these measurements without any further information on characteristic river parameters. Determination of these parameters is an identification problem, which is solved using the DUD procedure. The quality of the discharge determination can be estimated by comparing the result with the original upstream boundary condition in FATS, supposed to be 'true'. Finally, in chapter 6, attention is paid to the field work and equipment required to obtain real measurements for the discharge determination. Using the FINDQ-DUD algorithm, the river discharge as a function of time can then be computed to a certain degree of accuracy, which is the eventual aim of this study.