Michał Wasilewicz

Abstract

Accurate determination of amounts of rainfall in a catchment area, in the context of duration and exceedance probability, forms the basis for the design and verification of drainage (sewerage) systems in cities, and for stormwater management based on hydrodynamic models. Existing rainfall models are the ones used most commonly in supplying simulation models. The development and implementation of PMAXTP models by Poland’s Institute of Meteorology and Water Management (IMGW-PIB) in 2022 (based on rainfall data from 100 rain gauges from the period 1986-2015), covering the entire territory of Poland, has ensured free access to current and reliable information regarding local maximum amounts of rainfall (unit intensities).

This study presents the results of analyses comparing rainfall amounts with specific characteristics (durations ranging from 5 to 4320 minutes and probabilities from 2 to 50%), as determined using the probabilistic PMAXTP model for the Warsaw-Bielany Meteorological Station, as set against corresponding values from the Błaszczyk and Bogdanowicz-Stachý models used commonly in Poland. Given doubts cited in the study as regards correctness of method and data, it is advisable to extend support to a position presented by various researchers, that the Błaszczyk model for the design of sewer systems be discontinued. On the other hand, in general the maximum amounts of rainfall (quantiles) from the probabilistic PMAXTP model for the Warsaw-Bielany Station are seen to exhibit lower values as compared with corresponding data from the prob abilistic Bogdanowicz-Stachý model (for the central region), for rainfall durations ranging from 15 to 1440 minutes, and for all assumed levels of probability of rainfall. The differences between amounts of rainfall predicted by the two models do achieve significance in some cases. The authors also found that the amounts of rainfall considered from the PMAXTP model in relation to the upper confidence interval are also lower than the corresponding values from the Bogdanowicz-Stachý model, where rainfall duration is in the 15- to 720-minute range (denoting the values used most commonly in practice). In such a situation, use of the PMAXTP model for the Warsaw-Bielany Station in the designing of a sewer system would generally suggest lower diameters of pipe than would the values obtained using the Bogdanowicz-Stachý model. The advice is thus for the modelling of drainage systems for other areas of Poland to first compare amounts of rainfall from the PMAXTP model with data from other (including local) rainfall models. Our analyses also included verification as to the spatial variability of rainfall from the PMAXTP models, in relation to the performance of the sewer system in the area around Warsaw’s Chopin Airport. Equally, corresponding values were found to be similar in a comparison of amounts of rainfall suggested by the PMAXTP model for one of that project’s 100 measurement stations (i.e. Warsaw-Bielany) and the synoptic Warsaw-Okęcie Station (approximately 13 km away, and located within the studied catchment area of Warsaw’s Potok Służewiecki) – in this case determined through interpolation of data from measurement stations. The studied catchment area of 17.8 km² was also found to be characterized by minimal variability in the quantile values for rainfall with the rainfall event considered (p=20%, t=15 min).

However, significant differences in amounts of rainfall generated by the PMAXTP models are to observed between the Warsaw-Bielany and Świder measurement stations, located about 27 km apart. The quantile rainfall amounts for the Świder Station exceed the corresponding upper confidence-interval rainfall values for the Warsaw-Bielany Station. These differences in rainfall confirm that the use of local maximum-rainfall models in designing sewer systems is justified. Hydrodynamic simulations in the SWMM model determined that choice of rainfall models adopted impacted significantly on maximum values for flows in the catchment studied. The flows obtained under the catchment loading with the Bogdanowicz-Stachý model are substantially greater than those from the PMAXTP model; while the value obtained in response to rainfall using the Błaszczyk model stands out significantly. Information was further obtained concerning overloads in specific stormwater drains in the vicinity of Chopin Airport, as well as rainwater overflows from that area’s network of drains. All of this denotes the wisdom and justification of the hydraulic efficiency of systems of sewers and drains being verified using a hydrodynamic model.

Keywords: PMAXTP rainfall model, Bogdanowicz-Stachý model, Błaszczyk model, maximum rainfall, SWMM hydrodynamic model, stormwater sewer system

Mariusz Paweł Barszcz [mariusz_barszcz@sggw.edu.pl], Szkoła Główna Gospodarstwa Wiejskiego w Warszawie, Instytut Inżynierii Środowiska
Ewa Kaznowska [ewa_kaznowska@sggw.edu.pl], Szkoła Główna Gospodarstwa Wiejskiego w Warszawie, Instytut Inżynierii Środowiska
Michał Wasilewicz [michal_wasilewicz@sggw.edu.pl], Szkoła Główna Gospodarstwa Wiejskiego w Warszawie, Instytut Inżynierii Środowiska

Citation

APA: Barszcz, M., Kaznowska, E., & Wasilewicz, M. (2024). Analiza wysokości opadów maksymalnych z modelu PMAXTP i ich zastosowanie do weryfikacji działania miejskiego systemu odwodnienia. Przegląd Geograficzny, 96(4), 473-494. https://doi.org/10.7163/PrzG.2024.4
MLA: Barszcz, Mariusz Paweł, et al. "Analiza wysokości opadów maksymalnych z modelu PMAXTP i ich zastosowanie do weryfikacji działania miejskiego systemu odwodnienia". Przegląd Geograficzny, vol. 96, no. 4, 2024, pp. 473-494. https://doi.org/10.7163/PrzG.2024.4
Chicago: Barszcz, Mariusz Paweł, Kaznowska, Ewa, and Wasilewicz, Michał. "Analiza wysokości opadów maksymalnych z modelu PMAXTP i ich zastosowanie do weryfikacji działania miejskiego systemu odwodnienia". Przegląd Geograficzny 96, no. 4 (2024): 473-494. https://doi.org/10.7163/PrzG.2024.4
Harvard: Barszcz, M., Kaznowska, E., & Wasilewicz, M. 2024. "Analiza wysokości opadów maksymalnych z modelu PMAXTP i ich zastosowanie do weryfikacji działania miejskiego systemu odwodnienia". Przegląd Geograficzny, vol. 96, no. 4, pp. 473-494. https://doi.org/10.7163/PrzG.2024.4