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.

a b s t r a c tThe paper presents a research monitoring platform implemented for the Sulejow dam reservoir located in Central Poland; the goal was to assess the quality status of the reservoir's waters during the vegetation season of 2015. Article presents the results of mobile field measurements together with laboratory analyses of biogenic parameters, in order to provide a broad picture of changes in water quality during the analysed period. Changes in water quality were evaluated based on the following parameters: chlorophyll a, ammonium ions, pH, water temperature, blue-green algae concentration, conductivity and dissolved oxygen. Analysis was complemented by laboratory measurements of the chemical parameters: nitrates, phosphates, 5-d biochemical oxygen demand, chemical oxygen demand and total organic carbon. Extensive mobile experiments enabled the mapping of the distribution of contaminants in the lake (ArcGIS). Chlorophyll a exceeded allowable values during the entire vegetation season; furthermore, the high water temperatures, high concentrations of dissolved oxygen and low concentrations of biogenic compounds illustrate the advanced eutrophication of the reservoir. Present conditions prevent any recreational use of the reservoir and generates not only environmental but also economic losses.

This paper discusses the challenges to a wider access to archival cartographic materials. The aim of the study is to present and evaluate the preparation of historical maps for presentation in geoportals. The authors use the example of two maps from the early twentieth century, without information on the spatial relations, to trace the course of their processing into a form that allows them to be published in spatial data structures. The descriptions of subsequent stages include theoretical and practical aspects of the procedure. Particular attention was paid to the factors affecting the accuracy of spatial fit that affects the ability to use them further.

The authors have undertaken the development of DEM based on the archived materials from the time when the area of present Sulejów Lake was not an artificial water reservoir. The source materials used were Area Map of Administrative Districts in the scale of 1:25,000 from 1961 and a 1:1,000 documental map attached to the study Sulejowski Reservoir-study of sedimentation and updating of depth. The effect of this work was the creation of a Digital Geomorphological Model of the area that presently does not exist. In the second stage of works a bottom model of Sulejów Lake was made based on data gathered during echo sounding research conducted in 2008 by the Institute of Meteorology and Water Management, which comprises 36 profiles. Both models were then compared with tools available in the ArcGis program by ESRI. The analysis revealed differences resulting from processes that occurred during the construction and 40 years of existence of the reservoir.

Keywords: online monitoring; dam reservoir; water quality; multi-parameter probe; eutrophication