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The main aim of the study was to determine whether the amount and share of incidental water in wastewater inflows to the sewage treatment plant increased with the age and development of the sewage system. The object of the study is a small sewerage system located in southern Poland, in the Lesser Poland Province, 15 km north-east of the Kraków city. Analysis of a 15-year observation series of daily wastewater flows, from 01.01.1994 to 31.12.2018, allowed a reliable assessment of the actions taken by the sewage system operator to reduce sources of incidental water inflow to the sewage network. The study showed that the percentage share of incidental waters in the annual wastewater inflow to the analysed treatment plant decreased from 35.9% in 2004 to 8.4% in 2018. This reduction should be treated as a success of the remedial actions of the sewage system operator. However, the study showed at the same time that in 2017 alone, 56 709 m3 of incidental water flowed into the analysed sewerage system, compared to 166 075 m3 of wastewater. A similar case was repeated in 2013, when 53 060 m3 of incidental water and 132 860 m3 of real wastewater flowed into the treatment plant. These cases show that all remedial measures by the network operator are still insufficient when heavy and long-duration precipitation occurs in a given year.

W pracy przedstawiono wyniki analiz z wykorzystaniem dwóch modeli - konceptualnego modelu Wackermana oraz syntetycznego hydrogramu jednostkowego NRCS-UH - do określenia przepływów w zlewni rzeki Słonka, znajdującej się na obszarze Polski. Wybrane modele charakteryzują się łatwością określenia danych wejściowych do modelu, co jest istotne w aspekcie obliczeń inżynierskich. Obliczenia wykonano dla przepływów o prawdopodobieństwie wystąpienia przekroczenia wynoszącym: 0,5%, 1%, 2%, 5%, 10%, 20% i 50 dla różnych poziomów uwilgotnienia zlewni.

The aim of this study is to present the application of statistical methods to assess the possibility of grouping precipitation according to their elevation above sea level and precipitation levels in the temperate climate of Poland. The country was divided into regions with similar levels of precipitation using cluster analysis by Ward’s method. The study was performed with meteorological data on average monthly precipitation of 53 meteorological stations from 1981 to 2010. The selection of stations was dictated by the need to consider the variability in amounts of annual precipitation throughout the country. The data was used to calculate average annual precipitation total as well as average precipitation total in the summer half-year (from May to October) and the winter half-year (from November to April) for Poland, from 1981 to 2010. Statistical method was performed and six clusters were generated, for the elevation of the stations and average annual precipitation as well as average precipitation for hydrological half-years. The average annual precipitation for the clusters ranged from 530 mm (cluster 5) to 820 mm (cluster 2). The average precipitation for the winter hydrological half-year ranged from 190.1 mm (cluster 1) to 288.8 mm (cluster 5). The average precipitation for the summer hydrological half-year ranged from 326.3 mm (cluster 5) to 605 mm (cluster 2). The conclusions from the analysis carried out in the study are that: (1) grouping by means of Ward’s method can be used to distinguish homogeneous areas with the same levels of precipitation; (2) both precipitation and the elevation, at which meteorological stations are located, are the basis for distinguishing clusters in Ward’s method.

The aim of the study was to compare two grouping methods for regionalisation of watersheds, which are similar in respect of low flow and chosen catchments parameters (physiographic and meteorological). In the study, a residual pattern approach and cluster analysis, i.e. Ward's method, were used. The analysis was conducted for specific low flow discharge q95 (dm3·s-1·km-2). In the analysis, 50 catchments, located in the area of the upper and central Vistula River basin, were taken. Daily flows used in the study were monitored from 1976 to 2016. Based on the residual pattern approach (RPA) method, the analysed catchments were classified into two groups, while using the cluster analysis method (Ward's method) - into five. The predictive performance of the complete regional regression model checked by cross-validation R2 cv was 47% and RMSEcv = 0.69 dm3·s-1·km-2. The cross validation procedure for the cluster analysis gives a predictive performance equal to 33% and RMSEcv = 0.81 dm3·s-1·km-2. Comparing both methods, based on the cross-validated coefficient of determination (R2 cv), it was found that the residual pattern approach had a better fit between predicted and observed values. The analysis also showed, that in case of both methods, an overestimation of specific low flow discharge q95 was observed. For the cross-validation method and the RPA method, the PBIAS was -10%. A slightly higher value was obtained for the cross-validation method and models obtained using cluster analysis for which the PBIAS was -13.8%. [ABSTRACT FROM AUTHOR]

The paper presents an attempt to forecast heavy metal pollution of sediments of four designed reservoirs in southern Poland. For this purpose, concentration of dissolved heavy metals (lead, cadmium and nickel) was determined in water of watercourses on which the designed reservoirs will be constructed and also in sediments and water flowing into six reservoirs that are already in use. Based on the results of the heavy metal concentrations of six exploited reservoirs, a relationship was developed between heavy metal concentration in the sediment as a function of the concentration of these metals in the inflowing water. Using these relationships, the forecast concentrations of these metals in the sediments of the designed reservoirs were estimated. The mean concentrations of these metals in the planned reservoirs were 20.5 mg.kg-1 for lead, 3.4 mg.kg-1 for cadmium and 14.8 mg.kg-1 for nickel. No dangerous pollution of analyzed metal of water inflows to the planned reservoirs was found. The calculated geoaccumulation index indicates that in terms of the lead and nickel concentrations, sediments in the planned reservoirs will be unpolluted to moderately polluted, while for cadmium concentrations - they will be moderately to strongly polluted. [ABSTRACT FROM AUTHOR]

The main aim of the study was to determine whether the amount and share of incidental water in wastewater in- flows to the wastewater treatment plant increased with the age and development of the sewage system. The object of the study is a small sewerage system located in southern Poland, in the Lesser Poland Province, 15 km northeast of the Kraków city. The analysis of a 15-year observation series of daily wastewater flows, from 01.01.1994 to 31.12.2018, allowed a reliable assessment of the actions taken by the sewage system operator to reduce the sources of incidental water inflow to the sewage network. The study showed that the percentage share of incidental waters in the annual wastewater inflow to the analysed treatment plant decreased from 35.9% in 2004 to 8.4% in 2018. This reduction should be treated as a success of the remedial actions of the sewage system operator. However, the study showed at the same time that in 2017 alone, 56 709 m³ of incidental water flowed into the analysed sewerage system, compared to 166 075 m³ of wastewater. A similar case was repeated in 2013, when 53 060 m³ of incidental water and 132 860 m³ of real wastewater flowed into the treatment plant. These cases show that all remedial measures by the network operator are still insufficient when heavy precipitation occurs in a given year for a long period of time. [ABSTRACT FROM AUTHOR]

The purpose of the paper is to analyze the spatial variability of precipitation in Poland in the years 1981–2010. The average annual rainfall was 607 mm. Precipitation in Poland is characterized by high spatial and temporal variability. The lowest annual precipitation was recorded in the central part of the country, where they equaled 500 mm. The highest annual precipitation totals were determined in the south, equaling 970 mm. The average precipitation in the summer half-year is 382 mm (63% of the annual total). On the basis of data from 53 climate stations, maps were made of the spatial distribution of precipitation for the period of the year and winter and summer half-year. The kriging method was used to map rainfall distribution in Poland. In the case study, cross-validation was used to compare the prediction performances of three periods. Kriging, with exponential type of semivariogram, gave the best performance in the statistical sense. Their application is justices especially in areas where landform is very complex. In accordance with the assumptions, the mean prediction error (ME), mean standardized prediction error (MSE), and root mean-square standardized prediction error (RMSSE) values are approximately zero, and root-mean-square prediction error (RMSE) and average standard error (ASE) reach values well below 100. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum Polonorum. Formatio Circumiectus is the property of Wydawnictwo Uniwersytetu Rolniczego im. Hugona Kollataja w Krakowie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Scientiarum Polonorum. Formatio Circumiectus is the property of Wydawnictwo Uniwersytetu Rolniczego im. Hugona Kollataja w Krakowie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the paper the possibility of using statistical method for data agglomeration, i.e. nonhierarchical cluster analysis for low flow grouping was made. The study material included daily flows from the multi-year period of 1963-983 collected for 19 catchments, located in the upper Vistula basin. Regions with the same flow were determined with the use of nonhierarchical cluster analysis (K-means). Groups were characterized by low flow and selected physiographic and meteorological features of the catchments. The procedure of catchments assigning to the clusters was started from two clusters and finished at five. The next moving and assigning of catchments into clusters resulted in a cluster in which there was only one catchment (for five clusters). Another objects' delineation did not give an objective effects, based on which it was difficult to determine a clear criterion of assigning each catchments into the clusters. The last step involved development of the models reflecting correlation and regression relationships. The identified clusters comprised catchments similar in terms of unit runoff, watercourse length, mean precipitation, median altitude, mean catchment slope, watercourse staff gauge zero, area covered by coniferous forests, arable lands, and soils. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum Polonorum. Formatio Circumiectus is the property of Wydawnictwo Uniwersytetu Rolniczego im. Hugona Kollataja w Krakowie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Scientiarum Polonorum. Formatio Circumiectus is the property of Wydawnictwo Uniwersytetu Rolniczego im. Hugona Kollataja w Krakowie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Scientiarum Polonorum. Formatio Circumiectus is the property of Wydawnictwo Uniwersytetu Rolniczego im. Hugona Kollataja w Krakowie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of the study is to evaluate the mean annual precipitation in the mountain river catchment area, in the period between 1984-2012. Data on daily rainfall totals was obtained from IMGW PIB in Warsaw, and it came from two weather stations: one in Nowy Sącz, and the other in Krynica. It has been demonstrated that during the multi-year period covered by the study, there were variations in terms of precipitation levels; the year 1987 should be considered extremely dry, while 2010, extremely wet - in the latter year, extreme rainfall was noted. In the analysed multi-year period, within the total annual precipitation, rain dominated during the first half year, which undoubtedly affects the hydrological regime of the Kamienica river. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum Polonorum. Formatio Circumiectus is the property of Wydawnictwo Uniwersytetu Rolniczego im. Hugona Kollataja w Krakowie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The main objective of the paper is to estimate the influence of time of concentration (TC) on maximum flow in an urbanized watershed. The calculations of maximum flow have been carried out using the Rational method, Technical Release 55 (TR55) procedure based on NRCS (National Resources Conservation Services) guidelines, and NRCS-UH rainfall-runoff model. Similarly, three methods were used to calculate the overland flow component of the TC: the Kerby method, the Morgali and Linsley method and the NRCS travel time method. The TC was calculated in a watershed located in Krakow city in Poland, małopolskie voivodeship. Total area of the watershed has about 180 ha. It's a highly urbanized watershed with a significant land cover (29.6% of total area) influencing the runoff, in the form of an impervious industrial area. The highest value of time of concentration was achieved for Morgali and Lindley method in case of the subwatershed with dominant pervious areas, as opposed to the NRCS method for the subwatershed with dominant impervious areas. The highest value of TC was obtained for NRCS method. With reference to the whole watershed, the highest values of the time of concentration were obtained for the MorgaliandLindley method and the lowest for the Kerby formula. Based on this study, authors recomended the Kerby method for estimating TC for overland surface dominated areas because this method requires only a small number of input parameters, that are straightforward to estimate. [ABSTRACT FROM AUTHOR]

Our paper evaluates the effectiveness of pollutant removal from stormwater in a semi-natural treatment plant and develops stochastic models of their transformations in a soil bed. The examined wastewater treatment facilities consisted of reduction chambers and a retention-infiltration reservoir. The following indicators of pollution were subjected to analysis: BOD5, COD, total suspended solids, and chlorides. It was shown that COD, total suspended solids, and chlorides are the indicators that have the greatest impact on stormwater quality. However, the possibility of removal of the analyzed pollutants from stormwater is affected by the sedimentation process occurring in the reduction chambers and in the retention-infiltration reservoir, as well as by the process of infiltration through the soil bed. The developed models of pollutant transformation during wastewater infiltration through the bed were presented as the regression equations, where the selected pollution indicators in the filtrate were the dependent variable, while the analyzed pollution indicators in water from the retention-infiltration reservoir, coefficients of constant reaction kinetics determined for each variable, and the time of infiltration of wastewater through the soil bed were adopted as independent variables. [ABSTRACT FROM AUTHOR]