A critical evaluation of the methods for the determination of required volumes for detention tank

Rzeszow University of Technology, Department of Infrastructure and Water Management, al. Powstańców Warszawy 6, 35-959 Rzeszów, Poland

^* Corresponding author: mstarzec1990@prz.edu.pl

Abstract

Simplified methods allow a straightforward and quick determination of parameters of interest. A simplified method of calculation to be used must provide sufficiently accurate simulation results. This paper presents the results of tests completed to evaluate the effects of the parameters which describe a sewer catchment area and network on the value of T_p, a parameter applied in the Dziopak method [18]. The results of 2997 hydrodynamic simulations allowed to formulate an artificial neural network the application of which enabled the determination of the value of T_p dependent on the design parameters of a sewer catchment area and network. The artificial neural network had a very low error R² = 0.9972 between the expected and determined values of T_p. The completed tests indicated a relationship by which an increase of the rainfall duration, a parameter used in the dimensioning of detention tank, is concomitant to an increase in the value of T_p. The calculations made so far included an assumption that the T_p value is constant irrespective of the design rainfall duration for the dimensioning of detention tank; this assumption has led to gross calculation errors. The paper also provides proof that the inclusion of these relationships allows a more precise determination of the service volume required for a multi-chamber detention tank.