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.

Frequency and magnitude variability of Yalu River flooding: numerical analyses for the last 1000 years

Abstract: . Accurate determination of past flooding characteristics is necessary to effectively predict the future flood disaster risk and dominant controls. However, understanding the effects of environmental forcing on past flooding frequency and magnitude is difficult owing to the deficiency of observations (data available for less than 10 % of the world's rivers) and extremely short measurement time series ( years). In this study, a numerical model, HYDROTREND, which generates synthetic time series of daily water discharge at a river outlet, was applied to the Yalu River to (1) reconstruct annual peak discharges over the past 1000 years and estimate flood annual exceedance probabilities and (2) identify and quantify the impacts of climate change and human activity (runoff yield induced by deforestation and dam retention) on the flooding frequency and magnitude. Climate data obtained from meteorological stations and ECHO-G climate model output, morphological characteristics (hypsometry, drainage area, river length, slope, and lapse rate), and hydrological properties (groundwater properties, canopy interception effects, cascade reservoir retention effect, and saturated hydraulic conductivity) form significant reliable model inputs. Monitored for decades, some proxies on ancient floods allow for accurate calibration and validation of numerical modeling. Simulations match well the present-day monitored data (1958–2012) and the literature records of historical flood events (1000–1958). They indicate that flood frequencies of the Yalu River increased during 1000–1940, followed by a decrease until the present day. Frequency trends were strongly modulated by climate variability, particularly by the intensity and frequency of rainfall events. The magnitudes of larger floods, events with a return period of 50 to 100 years, increased by 19.1 % and 13.9 %, respectively, due to climate variability over the last millennium. Anthropogenic processes were found to either enhance or reduce flooding, depending on the type of human activities. Deforestation increased the magnitude of larger floods (100- and 50-year floods) by 19.2 %–20.3 %, but the construction of cascade reservoirs in 1940 significantly reduced their magnitude by 36.7 % to 41.7 %. We conclude that under intensified climate change and human activities in the future, effective river engineering should be considered, particularly for small- and medium-sized mountainous river systems, which are at a higher risk of flood disasters owing to their relatively poor hydrological regulation capacity.

Green approaches in river engineering - supporting implementation of Green Infrastructure

Abstract: Working together with natural systems, which are powered by a diversity of life within them, provides a range of benefits to society, ranging from carbon storage, clean water and air to reduction of climate change impacts and protection against floods and other environmental hazards. This realisation has led to the concept of Green Infrastructure (GI): a network of natural and semi-natural features that intersperses and connects villages, towns and cities. Rivers are part of this green network, which has the potential to provide higher resilience and cost-effectiveness as well as more social and environmental benefits than conventional infrastructure. This document focuses on river engineering (which is concerned with river works) and therefore, we consider the river or watercourse as a natural or semi-natural corridor or infrastructure element. In this context, GI approaches are those that promote the conservation or restoration of the natural (green) character of our rivers. These approaches are fundamental to improving the water quality, morphology and ecosystems of rivers as well as contributing to an overall strategy to help people and communities adapt to the impacts of climate change.

Rehabilitation of the River Rhine : proceedings of the International Conference on Rehabilitation of the River Rhine, 15-19 March, 1993, Arnhem, The Netherlands

Abstract: Biological communities in the river as affected by environmental changes emission and fate of pollutants control of accidental spills and clean-up measures assessment of ecotoxicological effects restoration of fish stocks and river floodplains ecological river engineering conclusions and recommendations. (Part contents).