Papers by Katarzyna Krężałek
The aim of the study was to determine the values of selected quantiles of probability distributio... more The aim of the study was to determine the values of selected quantiles of probability distribution of annual maximum daily rainfall in the area of central Poland, and their variability. The material for the study consists of measurement data from the multiannual period 1966–2010 gathered by 29 weather stations. Four types of probability distribution functions have been selected to be possibly used as mathematical models of random properties of annual maximum daily rainfall: Weibull, loggamma, gamma and log-normal. The parameters of probability distributions were estimated using the maximum likelihood method, and the best fitting probability distribution was selected for each station separately using the Akaike criterion. The results are presented in the form of a table of annual maximum daily rainfall with probabilities of exceedance p = 1%, p = 10%, p = 50% for the analyzed weather stations, and graphically in the form of precipitation fields and isohyetal maps drawn for the above ...
Acta Scientiarum Polonorum Formatio Circumiectus
The purpose of the work was to present the results of simulation studies of river runoff carried ... more The purpose of the work was to present the results of simulation studies of river runoff carried out with the use of a conceptual model specially developed for this purpose for an urbanized lowland catchment. Different variants of forecasts were developed of the impact of introducing various forms of urbanization on the formation of river runoff during freshets in the small, lowland catchment of upper Mławka river, covering the area of 66 km 2. For the needs of the research, classification of urbanized areas was made based on their location within the catchment, and the method of discharging rainfall runoff. Particular variants differed from one another as to the location of sealed areas, the degree of urbanization of the catchment, the initial waterlogging of the catchment, as well as the basic precipitation assumed for calculations. They provided the foundations for the assessment of the impact of various forms of urbanization of the catchment area on the formation of freshets, taking into account the catchment's natural properties, such as the occurrence of variable source areas. The subject of the analysis was not only the total runoff volume, but also its components-surface, subsurface and groundwater runoff. Analysis of the results of river runoff simulation, taking into account the components of this runoff, leads to the conclusion that the total increase of direct runoff volume and its peak value are caused not only by direct supply from sealed surfaces, but also from indirect impact, causing changes in the runoff regime in areas not covered by urbanization. Sealed and channelled areas located beyond the maximum range of active (variable source) areas, on which direct runoff does not occur in natural conditions, increase the runoff area in the scale of the catchment area as a whole. To compare, the peak freshet values for variants associated with urbanization and channelling outside the variable source areas are between 20% and 40% higher than in the case of analogous conditions and the sealing of the same area in the area of direct runoff.
Acta Scientiarum Polonorum Formatio Circumiectus
The aim of the work is to present a new hydrological model, developed at the Institute of Technol... more The aim of the work is to present a new hydrological model, developed at the Institute of Technology and Life Sciences (Instytut Technologiczno-Przyrodniczy), which can be used to simulate and study the formation of total runoff and its components from a small lowland agricultural catchment, in various meteorological conditions, taking into account the different initial retention status of the catchment and the impact of urbanized areas on the said runoff. The study involved the necessity of choosing the type of the model, and the manner of describing hydrological processes. Based on studying subject literature, as well as on the results of previous research and observations conducted in the upper Mławka river catchment (left tributary of the Wkra river), it was assumed that the most appropriate tool for prognostic and simulation purposes would be a conceptual model, that-in its structure and description of hydrological processes-would take into account the theory of active areas (variable source areas). It was assumed that a simple model would be developed as far as possible, that would create the possibility of simulating hydrographs of total runoff, surface runoff, subsurface runoff, and ground runoff from a natural catchment, and from catchments which have been urbanized to varying degrees. The work also includes the presentation of proposed principles for the classification of urbanized areas, taking into account their location within the catchment area and the way of draining rainwater, as well as a description of adequate modules of the model that would make it possible to simulate the runoff from the urbanized sub-catchments. The model is described by the state-space representations (differential equations) and output equations. It works with a one-hour time interval. The input is total precipitation and reference evapotranspiration. On the output end, we receive the total runoff hydrograph, and the hydrographs of the components of this runoff. The model includes 10 optimized parameters, occurring in procedures simulating processes in the natural, non-transformed part of the catchment, and 10 measurable parameters used to describe partially urbanized catchments. The article presents the results of identifying the parameters for the model, and of its verification. For this purpose, 5 hydrographs of total runoff were used, between 192 and 432 hours long, including storm surges. They were recorded in the catchment of the upper-course Mławka river. The obtained values of the criterion functions lead us to conclude that the quality of the model is very good. The model has been used for simulation studies of the impact of urbanization of the agricultural catchment on the parameters of river runoff (Krężałek 2018).
Journal of Water and Land Development, 2010
Evaluation and verification of the WetSpa model based on selected rural catchments in Poland The ... more Evaluation and verification of the WetSpa model based on selected rural catchments in Poland The paper presents results of calibration and verification of the WetSpa model, which enables the modelling of rainfall-runoff process based on mass and energy balance in the soil-plantatmosphere system in the catchment. It is a model with distributed parameters, using the structure of raster GIS model to determine the spatial diversity of the catchment environment. This enables simulation of runoff from the catchment, including: precipitation, evapotranspiration, interception of plant surface and soil cover, infiltration and capillary rise in soil and groundwater runoff. Simulated processes depend on the required non-distributed parameters, which were calibrated based on hydrometeorological data from the three rural catchments with different physical and geographical characteristics: Mławka, located in the Wkra basin in Central Poland and the rivers Kamienna and Sidra, which are tributaries...
Acta Scientiarum Polonorum Formatio Circumiectus, 2018
The aim of the work is to present a new hydrological model, developed at the Institute of Technol... more The aim of the work is to present a new hydrological model, developed at the Institute of Technology and Life Sciences (Instytut Technologiczno-Przyrodniczy), which can be used to simulate and study the formation of total runoff and its components from a small lowland agricultural catchment, in various meteorological conditions, taking into account the different initial retention status of the catchment and the impact of urbanized areas on the said runoff. The study involved the necessity of choosing the type of the model, and the manner of describing hydrological processes. Based on studying subject literature, as well as on the results of previous research and observations conducted in the upper Mławka river catchment (left tributary of the Wkra river), it was assumed that the most appropriate tool for prognostic and simulation purposes would be a conceptual model, that-in its structure and description of hydrological processes-would take into account the theory of active areas (variable source areas). It was assumed that a simple model would be developed as far as possible, that would create the possibility of simulating hydrographs of total runoff, surface runoff, subsurface runoff, and ground runoff from a natural catchment, and from catchments which have been urbanized to varying degrees. The work also includes the presentation of proposed principles for the classification of urbanized areas, taking into account their location within the catchment area and the way of draining rainwater, as well as a description of adequate modules of the model that would make it possible to simulate the runoff from the urbanized sub-catchments. The model is described by the state-space representations (differential equations) and output equations. It works with a one-hour time interval. The input is total precipitation and reference evapotranspiration. On the output end, we receive the total runoff hydrograph, and the hydrographs of the components of this runoff. The model includes 10 optimized parameters, occurring in procedures simulating processes in the natural, non-transformed part of the catchment, and 10 measurable parameters used to describe partially urbanized catchments. The article presents the results of identifying the parameters for the model, and of its verification. For this purpose, 5 hydrographs of total runoff were used, between 192 and 432 hours long, including storm surges. They were recorded in the catchment of the upper-course Mławka river. The obtained values of the criterion functions lead us to conclude that the quality of the model is very good. The model has been used for simulation studies of the impact of urbanization of the agricultural catchment on the parameters of river runoff (Krężałek 2018).
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Papers by Katarzyna Krężałek