A method for quantifying the flow resistance exerted due to a single spur dike located in an open channel is presented. The work was carried out in a rigid bed flume, with the model spur dike being simulated using various sizes of a rectangular plate. The drag force exerted by the spur dike plate for both submerged and un-submerged flow conditions was directly measured using a specially-designed apparatus and also by applying the momentum equation to a control volume that included the plate. The results indicate that an increase in the blockage due to the spur dike plate is the main parameter responsible for an increase in the spur dike drag coefficient, hence the associated flow resistance. Based on the present experimental results, relationships are given to estimate the backwater effect due to a single spur dike. RÉSUMÉOn présente une méthode pour quantifier la résistance exercée par un épi unique situé dans un canal ouvert. Les études ont été effectuées dans un canal à fond fixe, avec un épi simulé à l'aide d'une plaque rectangulaire de différentes tailles. La traînée exercée sur la plaque épi submergée ou non a été directement mesurée en utilisant un appareil spécialement conçu et également en appliquant l'équation des quantités de mouvement à un volume de contrôle incluant la plaque. Les résultats indiquent qu'une augmentation dans le blocage par la plaque épi est le principal paramètre responsable de l'augmentation de la traînée de l'épi, donc de l'augmentation de la résistance à l'écoulement. Basées sur les présents résultats expérimentaux, des relations sont données pour estimer l'effet d'un épi unique sur la ligne d'eau.
Storm water detention ponds are usually designed to store-and-release the runoff of extreme rainfall events based on a selected return period, e.g., 100 years. The design storm is typically a recorded historical event or one that is extracted from historical intensity-duration-frequency (IDF) curves. In essence, the selected storm and the resulting design are deterministic. In this research, the inevitable natural weather variability and its impact on the uncertainty of extreme events are simulated and quantified. This study builds on the results of a previous study where a stochastic weather generator, LARS-WG, was used to generate an ensemble of series with a 30-year length of hourly rainfall in the city of Saskatoon, Canada, based on the statistical properties of historical rainfall. Here, the most critical day (24-h rainfall) of each of the series is identified as a possible realization of the design storm. The runoff of each realization of the storm events is routed to a storm water pond in Saskatoon using the XPSWMM model. The critical runoff volume collected in the pond throughout the 24-h duration is also identified. Empirical probability distributions are fitted to the critical values of runoff volumes collected in the pond and compared with the current design storage. Exceedance probabilities and expected flood risk are estimated from the probability distributions for the baseline period (1960-1990), as well as under three projected future (2014-2100) scenarios of climate change (RCP 2.6, 4.5, and 8.5). Along with the magnitude of expected risk, this method provides the probability of the infrastructure's failure due to uncertainty. The proposed risk-based approach presented in this study provides a way for municipalities to quantify the risk associated with their selected design values and for tangible and meaningful interpretation of the risks that projected climate change might pose on storm water infrastructure. The main finding of this study is that the distribution of rain throughout the storm event may play a more important role than the total rainfall depth when water ponding/flooding is the major concern. It is further concluded that risk analysis must be tailored to the type of infrastructure under consideration.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.