: 41-48
Lviv Polytechnic National University
Lviv Polytechnic National University, Department of Hydraulics and Sanitary Engineering

The theoretical analysis and comparison of the nonlinear reservoir method and the sector method of calculating the stormwater runoff hydrographs from the urbanized catchments are carried out in the paper. The key advantages of the sector method are in taking into account the variable depth and flow velocity of the surface flow. A comparison of stormwater surface runoff hydrographs for completely impervious square drainage subcatchments, obtained by the nonlinear reservoir method and by the sector method, is performed. The accuracy of the numerical implementation of the sector method was controlled by the deviation of the calculated volume of the stormwater runoff comparing to the corresponding theoretical value. The relative difference between the two indicated volumes for the entire investigated range of values of the input parameters did not exceed 0.002 %. It was established that the stormwater runoff hydrographs, obtained by the sector method, comparing with similar hydrographs for the nonlinear reservoir method are generally
characterized by considerably more intensive growing of the flow rate at the first stage of the hydrograph and the same quick reduction of the discharge after the rainfall event. The maximum calculation flow rates of the stormwater surface runoff hydrographs using the sector method for completely impervious square drainage subcatchments for the climatic conditions of the city of Lviv at the return period P = 1 year are 1.29 times higher than the corresponding volume discharges obtained using the nonlinear reservoir method. The invariance of generalized non-dimensional stormwater runoff hydrographs, modelled by the nonlinear reservoir method and by the sector method, was obtained for the following input parameters: absolute dimensions of square subcatchments, longitudinal slope of the territory and the roughness coefficient of the subcatchment’s surface.

1. Borah D. K. (2011), “Hydrologic procedures of storm event watershed models: a comprehensive review and comparison”, Hydrological Processes, Vol. 25, p. 3472–3489.

2. James W. and Rossman L. (2010), Water systems models. User’s guide to SWMM 5, 13th ed., CHI Press Publication, Ontario, Canada, 905 p.

3. Tkachuk S. G. and Zhuk V. M. (2012), Reghuljuvannja doshchovogho stoku v systemakh vodovidvedennja: monoghrafija. [Stormwater management in sewerage systems: monograph], Lviv: Vydavnyctvo Lvivskoji politekhniky, 216 p. [in Ukrainian].

4. Wang K. H. and Altunkaynak A. (2012), “Comparative case study of rainfall-runoff modeling between SWMM and fuzzy logic approach”, Journal of Hydrologic Engineering, Vol. 17, No. 2, p. 283−291.

5. Xiong Y. and Melching C. S. (2005), “Comparison of kinematic-wave and nonlinear reservoir routing of urban watershed runoff”, ASCE Journal of Hydrologic Engineering, Vol. 10, No. 1, p. 39−49.

6. Zhuk V. M. (2007), “Hidrohrafy prytoku dlia doshchiv postiinoi v chasi intensyvnosti ta liniinykh baseiniv stoku” [Runoff hydrographs for the rainfalls of constant intensity and linear catchments], Visnyk of Lviv Polytechnic National University “Theory and Practice of Construction”, N 602, p. 61–65 [in Ukrainian].

7. Zhuk V. M. and Matlay I. I. (2012), “Hidrohrafy prytoku doshchovykh stichnykh vod z priamokutnykh v plani urbanizovanykh baseiniv stoku dlia doshchiv postiinoi v chasi intensyvnosti” [Stormwater hydrographs from rectangular urbanized catchments for the rainfalls with constant intensity in time], Problems of Water Supply, Sewerage and Hydraulics, Vol. 19, Кyiv: KNUBA, p. 31–38 [in Ukrainian].

8. Zhuk V. M. (2015), “Vlyianye konfiguratsii malykh urbanizirovannykh basseinov stoka na gidrografy pritoka dozhdevykh stochnykh vod” [Influence of the configuration of small urbanized catchments on the stormwater hydrographs], Motrol. Commission of Motorization and Energetics in Agriculture, Vol. 17, No. 6, p. 111−117 [in Russian].