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Real-Time Operation of Reservoirs during Flood Conditions Using Optimization-Simulation with One- and Two-Dimensional Modeling
Published in Saeid Eslamian, Faezeh Eslamian, Flood Handbook, 2022
Hasan Albo-Salih, Larry W. Mays, Daniel Che
Flood forecasting studies endeavor to produce as accurate as possible future estimates of discharges from a reservoir-river system based on the present state, forecasted rainfall, and the past behavior of the river-reservoir system. Bálint (2002) defined flood forecasting as “an operational, result-oriented activity and as such pays less attention to the modeled system than to the output of the forecasting procedure.” The outputs are peak stage and/or flood crest, flood flow, and stage or discharge hydrographs, and flood volume. Flood forecasting and warning processes provide timely and reliable information to operators. The entire forecasting and warning process should be done in enough lead time to allow the decision-makers to take the possible measures to prevent or minimize the prospective flooding.
Torrential and Flash Flood Warning
Published in Saeid Eslamian, Faezeh Eslamian, Flood Handbook, 2022
Spyros Schismenos, Dimitrios Emmanouloudis, Garry John Stevens, Saeid Eslamian
Most hydrological models for flood forecasting are created for specific climates (e.g., temperate, mild Mediterranean, and damp tropical) and cannot be used effectively in regions with different conditions. Furthermore, these models are primarily designed for rivers and not for torrents, even though it is well known that large differences exist in the hydrologic behavior between them. Torrents develop in mountainous areas, have more intense flooding phenomena, steeper gradients, and more irregular discharges (long periods with little or no water in their channel, and then short periods with large discharges). Therefore, the same models that forecast the behavior of rivers cannot effectively forecast the behavior of torrents without substantial modifications (Emmanouloudis et al., 1970; Myronidis et al., 2009; Schismenos et al., 2020).
International water resources law
Published in Dante A. Caponera, Marcella Nanni, Principles of Water Law and Administration, 2019
Dante A. Caponera, Marcella Nanni
The methods most commonly used for the defence against floods are: construction of dykes, flood walls, levees or embankments to protect land from flood water and to keep it within the usual main channels;increasing the discharge capacity of the main channel by strengthening, widening or deepening it, or by a combination of the three;diverting part or the whole of the flood waters in excess of the carrying capacity of the main channel;constructing reservoirs to hold flood waters temporarily and releasing them later as the channel is capable of carrying them;taking steps to decrease the rate of discharge by improved land use practices, i.e., afforestation, substitution of erosion inducing crops with soil protecting crops;using flood forecasting and early warning systems to minimize loss of life and property;identifying and mapping flood-prone areas, in order to subject them to a special régime.50
Intricate flood flow advancement modelling in the krishna river sub basin, India
Published in ISH Journal of Hydraulic Engineering, 2023
Rangineni Pallavi, K. Rekha Rani, Kulkarni Shashikanth, P. Rajasekhar, Hiteshri Shashtri
Flood forecasting models essentially plan to estimate the water level and discharge of approaching flood. These forecasting models use data of flood flows and stages at strategic points in river basin to predict floods. The conventional method employs flood routing approaches such as river (channel) routing and reservoir routing. These routing techniques mainly aim to predict flood hydrographs at various sections. Furthermore, flood peak attenuation and duration of high water levels form essentially an efficient flood forecasting approach (Chow 1964). In river, during floods, the flow is non-uniform and unsteady. The hydraulic characteristics vary from stage to stage and also from channel to channel inclusive of later flows. The hydraulic routing method essentially involves the solution of Saint-Venant equation, whereas the hydrologic routing is traditionally based on the physical properties of the channel by applying methods such as Muskingum and Muskingum-Cunge (Chow 1964, Refsgaard 1997). However, with the advent of numerical methods and in combination with high-performance computing facilities, the flood modeling capabilities have increased and reliability of estimates has also increased in recent times (Timbadiya et al. 2014).
Coping with and adapting to urban floods: experiences of flood community-dwelling households in Aboabo, Ghana
Published in Urban Water Journal, 2023
Andrews Ofosu, Kabila Abass, Harrison Kwabena Owusu, Razak M. Gyasi
The study recommends a balanced use of structural and non-structural flood control mechanisms for effective flood adaptation. At the community level, drainage systems must be expanded to increase their capacity for detaining and conveying high stream flows. This must be supplemented with feeder channels that connect water into the main drainage system by the AMMA. A key requirement for addressing the flood menace is empowering the institutions to deliver on their mandate. This will require adequate financial injection by the AMMA. It also demands strict enforcement of land use regulations. Besides, an efficient waste management regime must be put in place by the AMMA. More importantly, public education on sustainable waste management practices and land use by key institutional stakeholders such as NADMO, AMMA, and traditional leaders should be sustained. Importantly, an effective system of flood forecasting and early warning is needed to protect vulnerable communities from during floods. A long-term solution will require a planned AMMA-supervised relocation of households dwelling within the River Aboabo flood plain. Supporting this with alternative livelihood programmes to empower these vulnerable households will be a laudable initiative. This, however, may potentially face some practical difficulties associated with the reluctance of households to relocate and funding. The way forward is a risk assessment of the current situation, a careful assessment of the cost and benefits of these initiatives, and broad stakeholder engagement.
An overview of river flood forecasting procedures in Canadian watersheds
Published in Canadian Water Resources Journal / Revue canadienne des ressources hydriques, 2019
Zahra Zahmatkesh, Sanjeev Kumar Jha, Paulin Coulibaly, Tricia Stadnyk
Flooding is the most common natural hazard globally (United Nations 2015). Due to the damage associated with floods, it has been known as the deadliest natural disaster after earthquake and tsunami (Balica et al. 2013). In Canada, floods are known as the most common, widely distributed, and the most costly natural disasters which threaten lives, properties, the economy, infrastructure, and environment (Henstra and Thistlethwaite 2017). Floods can happen at any time of the year, anywhere in Canada, with intensities and damages depending on the size of the watershed, location, and the main streams involved. Reliable and accurate flood forecasting can help to minimize some of the negative impacts associated with flood incidents. Flood forecasting consists of using hydro-meteorological information, meteorological forecasts and other watershed characteristics in a rainfall-runoff or streamflow routing model to estimate flow rates or water levels for a future time window (i.e., a few hours to days) (Jain et al. 2018).