The aim of the presented research was to examine the concentration of biogenic compounds and heavy metals in the bottom sediments of the Sulejów Reservoir (Central Poland) from October 2018. Based on the obtained research results, maps of the spatial distribution were prepared. The following parameters were analyzed: total phosphorus (TP), total Kjeldahl nitrogen, total organic carbon (TOC), ratio of total organic carbon to nitrogen (C:N), organic matter content as well as Cd, Cr and Pb concentrations. The sediments were collected at 28 sampling sites, covering the whole area of the reservoir. The differences in the content of individual biogenic compounds result from the composition of the debris applied by the supplying rivers, as well as the content of this elements in the water, long retention time (40 days) and depth from which the tested sediments were taken. The distribution of examined compounds was largely influenced by the agricultural activity in the studied area, as well as the presence of ports and recreational points. Based on the measurements, the highest amounts of biogenic components deposit in sediments of deep parts in slow-flowing waters, in stagnation zones, areas adjacent to arable land, and the sites where fine-size fractions prevail in the deposited material. Biogenic compounds in sediments of the Sulejów Reservoir showed a pattern of gradual increase along the reservoir from lower values in the back-water part. A similar relationship is visible for heavy metals. Referring to the ecotoxicological criteria, it can be stated that bottom sediments from the Sulejów Reservoir collected in 2018 are not toxicologically contaminated in terms of cadmium, lead and chromium content.

The paper presents results of water quality monitoring conducted within the frame of the MONSUL project. The main goal was to analyse and assess the impact of factors determining the ecological status of a dam reservoir on the basis of the Sulejow Reservoir located in Central Poland. The project implementation plan based on comprehensive research-based monitoring covered the following parameters characterising the ecological potential of the reservoir: water temperature, pH, oxygen concentration, chlorophyll “a” and blue-green algae, concentration of ammonium ion, nitrate nitrogen phosphates as well as total organic carbon, chemical oxygen demand and biochemical oxygen demand. The parameters were measured with a mobile and stationary monitoring system and supplemented by an off-line analysis of water samples in the laboratory. The study was carried out during two seasons: May–October 2015 and April–November 2016; the results were analysed also with regard to the weather conditions. Despite the similar temperatures of water and air in the analysed seasons, significant differences were observed for atmospheric precipitation; 2015 was a dry year, and the climatic water balance for the analysed area was negative, which caused limited surface runoff and decreased the concentrations of nutrient in the reservoir waters. Data from continuous monitoring, supplemented with the results of laboratory measurements, indicated that the values of TOC (Total Organic Carbon) and COD (Chemical Oxygen Demand) parameters were within the purity class I; exceedances refer to the BOD (Biochemical Oxygen Demand) value, which confirmed the presence of biodegradable organic compounds in the reservoir waters. The values of chlorophyll “a” and the presence of algae during the vegetation season testify to eutrophication of the Sulejow Reservoir.

The authors analyze topography changes related to the construction and operation of the Bełchatów Brown Coal Open Mine and Power Plant, one of Europe’s larger open-pit mines, situated in central Poland. In order to achieve this, a DEM (Digital Elevation Model) is prepared, based on archival materials from the pre-investment period. Source materials include German topographical maps, issued in 1944 by the Supreme High Command of the German Army (Oberkommando des Heeres/Generalstab). The second model of the same area is prepared based on DEM data included in the Topographical Database available by CODGiK (Main Centre of Geodetic and Cartographic Documentation). The preparation of two terrain models from different periods make it possible to evaluate the changes in the morphometry. Both models are compared using ArcGIS (ESRI) tools. The comparative analysis of the models allows for observing topography changes resulting from anthropogenic transformations related to the construction of the Brown Coal Open Mine Bełchatów and Power Plant complex.

The article is an attempt to present the attractiveness of the recreational area of Łagiewnicki Forest in Łódź as regards the diversity of its relief. The work is based on an analysis of digital elevation models, using GIS techniques and direct observations. Based on an analysis of the relief, the authors have proposed a new tourism trail focused on the ‘morphometric assets’ of the area.

The level of unemployment in a region can be a good illustration of its socio-economic development. The choice of the data modeling method, both in terms of spatial and time-spatial approaches depends on the results of exploratory data analysis. The aim of the research is to investigate which methods of GIS spatial analysis can be used for the cartographic presentation of the variability of the unemployment rate in Poland, broken down into provinces (voivodeships) and districts in terms of time and space. This goal will be achieved by performing an exploratory analysis of data on the unemployment rate in Poland for the period 2004–2022 in order to select the methods of cartographic presentation and transfer in spatial and time-spatial terms, along with selected cartographic methods in the GIS of the level of unemployment in Poland. This study, excluding data analysis based on statistical tests, focuses on examining the distribution of unemployment rates in Poland by districts and provinces from 2004 to 2022. This leads to the selection of optimal methods for the visualization and analysis of spatial data. The use of data analysis methods based on statistical tests and the examination of the distribution of data on the unemployment rate in Poland at county (district) and province (voivodeship) level for the period 2004–2022 will be performed in order to validate the results of the research. The selection of optimal methods of visualization and analysis of spatial data is intended to be a model for use in other areas of research.