Hydrological Analysis of a Dyke Pumping Station for the Purpose of Improving Its Functioning Conditions

Abstract

This paper presents a methodology of calculating the water transfer capacity of a dyke pumping station in flood wave conditions in order to improve its functioning, especially with regards to the safety of the areas being drained. The exemplary analysis was carried out for a pumping station situated on a small right-bank tributary of the Odra River in the southwest part of Poland, which, due to the inadequate capacity of its pumps, extensively flooded the surrounding areas in May and June 2010. Hydrological analyses were conducted in order to determine the rate of the designed and control flows using a spatial regression equation, and as a comparison, the rainfall-runoff method was also used. The corresponding flood-wave hydrographs were also determined, which included total precipitation using the German Association For Water Resources and Land Improvement (DVWK) method, effective precipitation using the Natural Resource Conservation Service curve number (NRCS-CN) method, as well as hypothetical waves using the instantaneous unit hydrograph (IUH) method. Flood-wave routing was carried out and alternative solutions for both the output of the required pumps and the retarding reservoir capacity were highlighted on this basis. The paper presents the possibility of a correct pump capacity selection, and in turn, the size of the pumping station retarding reservoir that results from this selection. This will enable pumping station exploitation costs or maintenance costs of the retarding reservoir to be considerably reduced.

Developing a mathematical framework in preliminary designing of detention rockfill dams for flood peak reduction

“…In this study, the inlet flood hydrograph into the reservoir is produced by Gamma Probability Distribution Function (Machajski & Kostecki, 2018). The PDF of the gamma distribution is:…”

“…Where m is the dimensionless shape factor of the inlet hydrograph, t p is the time of inlet flood hydrograph to reach the peak value; I p is the peak of input hydrograph. Several researchers have used this function to simulate inlet flood hydrograph in hydrologic studies (Aksoy, 2000;Gray, 1961;Machajski & Kostecki, 2018;Nash 1959). For example, Nash (1959), Gray (1961), Bhunya, Ghosh, Mishra, Ojha, and Berndtsson (2005) and Singh, Mishra, and Jain (2014) used this equation to derive unit hydrograph model of the flood.…”