Adam Krajewski

Curve Number Estimation for a Small Urban Catchment from Recorded Rainfall-Runoff Events

Abstract Runoff estimation is a key component in various hydrological considerations. Estimation of storm runoff is especially important for the effective design of hydraulic and road structures, for the flood flow management, as well as for the analysis of land use changes, i.e. urbanization or low impact development of urban areas. The curve number (CN) method, developed by Soil Conservation Service (SCS) of the U.S. Department of Agriculture for predicting the flood runoff depth from ungauged catchments, has been in continuous use for ca. 60 years. This method has not been extensively tested in Poland, especially in small urban catchments, because of lack of data. In this study, 39 rainfall-runoff events, collected during four years (2009–2012) in a small (A=28.7 km2), urban catchment of Służew Creek in southwest part of Warsaw were used, with the aim of determining the CNs and to check its applicability to ungauged urban areas. The parameters CN, estimated empirically, vary from 65.1 to 95.0, decreasing with rainfall size and, when sorted rainfall and runoff separately, reaching the value from 67 to 74 for large rainfall events.

Selected mechanical properties of Scots pine wood from antique churches of Central Poland

Scots pine (Pinus sylvestris L.) wood is the most frequently used building material in old churches of Central Poland. In the article, the density and compressive strength of Scots pine heartwood samples taken from old churches from the sixteenth, seventeenth, and eighteenth century were examined. The properties of the old wood were compared with contemporary wood of similar density. The results showed better quality of the ancient wood as compared to modern wood.

Predicted small catchment responses to heavy rainfalls with SEGMO and two sets of model parameters

Abstract Predicted small catchment responses to heavy rainfalls with SEGMO and two sets of model parameters. The study tests the ability of hydrological part of SEGMO (SedimentGraph Model), i.e. lumped parametric rainfall-runoff procedure of SEGMO to simulate design storm runoff in a Korean catchment. The aim of the investigation is to predict responses of small catchment of the Jeungpyeong river, located in central part of South Korea, with the area of 133.6 km2, to 100-year rainfall events, applying SEGMO and using two parallel approaches for model parameter estimation. The fi rst approach is based on catchment characteristics and USDA-SCS procedures, which is suitable for ungauged basins, and the other one is based on rainfall-runoff measurements. The way of estimation of model parameters has been demonstrated. Finally, the model outputs are compared. The difference in largest peak discharges obtained from SEGMO with the two sets of model parameters, i.e. when estimated on the base of catchment characteristics and USDA-SCS procedures, and on the base of rainfall-runoff measurements were relatively small, approaching 37%. This investigation can be seen as checking the uncertainties in model parameter estimation and their infl uence on fl ood fl ows. Streszczenie Przewidywane reakcje zlewni rzecznej na wysokie opady przy wykorzystaniu modelu SEGMO z dwoma zbiorami parametrów. Powodzie powodują straty społeczne, środowiskowe oraz ekonomiczne. Ryzyko związane z wystąpieniem powodzi wzrasta wraz z obserwowanymi zmianami klimatu i dotyczy coraz szerszego kręgu mieszkańców globu. W związku z tym, politycy, planiści i projektanci potrzebują informacji o skali zjawiska, które może wystąpić. Informacja ta musi być jednocześnie jak najbardziej wiarygodna. W zlewniach obserwowanych hydrologicznie istnieje możliwość zastosowania metod statystycznych w celu oszacowania przepływów maksymalnych prawdopodobnych. Alternatywą w małych zlewniach, gdzie zwykle brak wieloletnich danych pomiarowych, a które są również bardziej podatne na zmiany wpływające na ich reakcje, jest stosowanie modeli opad - - odpływ. W pracy przedstawiono zastosowanie modelu SEGMO do wyznaczenia reakcji rolniczo- leśnej zlewni Jeungpyeong, o powierzchni około 134 km2, położonej w centralnej części Korei Południowej na opad prawdopodobny o p = 1% i różnym czasie trwania. Obliczenia wykonano w dwóch wariantach, określając parametry modelu: (1) na podstawie charakterystyki zlewni (jak dla zlewni nieobserwowanej) oraz (2) na podstawie pomiarów opad-odpływ. Przeprowadzone badania potwierdziły użyteczność modelu do symulacji reakcji zlewni na opady maksymalne, wysoką zgodność parametru CN wyznaczania opadu efektywnego, ustalonego jako wartość tablicową z wartości z danych pomiarowych, oraz dobrą zgodność wyników (maksymalnych przepływów) uzyskanych z zastosowania dwóch ww. sposobów ustalenia parametrów modelu. Wskazano na istotne elementy dalszych badań

Modeling Suspended Sediment Concentration in the Stormwater Outflow from a Small Detention Pond

AbstractDetention ponds constructed in urban areas should perform two major functions: reduce flood flows and improve quality of runoff by trapping sediments and related pollutants. Providing tools...

Preliminary research on mortality of wood destroying Anobiidae (Coleoptera) following the application of p-dichlorobenzene in combination with low oxygen atmosphere fumigation

Abstract Experiments were undertaken in connection with the need, indicated in the literature, for the proper choice of a substance enhancing the effect of a low oxygen atmosphere used as a means of controlling wood boring insects in museum collections and historical objects. A low oxygen atmosphere itself causes the death of wood boring insects after a relatively long period of application. Thus, attempts were made to use p-dichlorobenzene to accelerate the effects of a low oxygen atmosphere in the control of wood boring insects. The experiments were performed as a continuation of preliminary research on the effect of p-dichlorobenzene on Anobiidae in an aerobic atmosphere. The paper present the results of gassing Anobium punctatum and Ptilinus pectinicornis (Coleoptera: Anobiidae) larvae with 1,4-dichlorobenzene in a low oxygen atmosphere of nitrogen and argon. The experiments were performed in laboratory conditions at a temperature of 20°C on larvae extracted from wood. The results do not show a faster elimination of larvae of either species using p-dichlorobenzene in a low oxygen atmosphere as compared to using p-dichlorobenzene in an aerobic atmosphere. Complete eradication of larvae in the test groups was obtained after 48 hours when using p-dichlorobenzene in nitrogen. The results obtained when using p-dichlorobenzene in argon appear to be worse at fumigation times shorter than 48 hours.

Susceptibility of hornbeam and Scots pine woods to destruction by the subterranean termite Reticulitermes lucifugus ROSSI, 1792 (Blattodea: Isoptera)

Abstract The article presents the results of tests of the degree of damage to Scots pine (Pinus sylvestris) and hornbeam (Carpinus betulus) woods by the termite Reticulitermes lucifugus. Both wood species are classified as “susceptible to destruction by termites” in the EN 350-2:2000 standard. The procedures described in the ASTM D 3345-08 standard (2009) were applied in the experiments. During laboratory coercion tests, wood samples from these two species were damaged to a degree between light attack and moderate attack with penetration. Recent Scots pine sapwood was damaged to a heavy degree. The results can be associated with the much higher density of hornbeam wood as compared to Scots pine sapwood. The mortality rate of the termites in the test containers with both wood species was similar and low, no greater than 10%. In the light of the results, the classification of the susceptibility of native wood species to termite feeding, as stated in the EN 350-2:2000 standard, appears to be oversimplified.