The main scientific goal of this work is the presentation of the role of selected geophysical methods (Ground-Penetrating Radar GPR and Electrical Resistivity Tomography ERT) to identify water escape zones from retention reservoirs. The paper proposes a methodology of geophysical investigations for the identification of water escape zones from a retention fresh water lake (low mineralised water). The study was performed in a lake reservoir in Upper Silesia. Since a number of years the administrators of the lake have observed a decreasing water level, a phenomenon that is not related to the exploitation of the object. The analysed retention lake has a maximal depth between 6 and 10 m, depending on the season. It is located on Triassic carbonate rocks of the Muschelkalk facies. Geophysical surveys included measurements on the water surface using ground penetration radar (GPR) and electrical resistivity tomography (ERT) methods. The measurements were performed from watercrafts made of non-metal materials. The prospection reached a depth of about 1 to 5 m below the reservoir bottom. Due to large difficulties of conducting investigations in the lake, a fragment with an area of about 5,300 m 2, where service activities and sealing works were already commenced, was selected for the geophysical survey. The scope of this work was: (1) field geophysical research (Ground-Penetrating Radar GPR and Electrical Resistivity Tomography ERT with geodesic service), (2) processing of the obtained geophysical research results, (3) modelling of GPR and ERT anomalies on a fractured water reservoir bottom, and (4) interpretation of the obtained results based on the modelled geophysical anomalies. The geophysical surveys allowed for distinguishing a zone with anomalous physical parameters in the area of the analysed part of the retention lake. ERT surveys have shown that the water escape zone from the reservoir was characterised by significantly decreased electrical resistivities. Diffraction hyperboles and a zone of wave attenuation were observed on the GPR images in the lake bottom within the water escape zone indicating cracks in the bottom of the water reservoir. The proposed methodology of geophysical surveys seems effective in solving untypical issues such as measurements on the water surface.
The purpose of this article is to present a new bell type water well construction with circulating treatment and its application. The construction of the water well has been developed and research has been conducted using physical and electrical modelling as well as in the practical field. Researches in this work are of analytical and experimental character. As the results of the research, optimal physical parameters of the constructions have been found and analytical empirical formulae have been derived to calculate hydraulic parameters. Recommendation for application has been presented. The results received in this work can be used for the application of well construction. Further research is required to improve the physical and the hydraulic parameters of the proposed construction. The work has scientific and practical interest.
Geographical names are extremely helpful in giving evidence of early settlements and their inhabitants due to their solid anchorage in the landscape, even in the case of population changes. Through the investigation of these place names, information can be gathered not only on the name giver, but also on the settlers who took on the names later on. Therefore, it is considered that any linguistic investigation has to start from the river and place names of a region. The utilization of geographical names yields the following findings: — The centre of Old Slavic names is situated on the northern slope of the Carpathian Mountains, approximately between Bukovina and Krakow; it is based on a substrate of older, Indo-European hydronyms. — The expansion of the East Slavic tribes bypasses the Pripyat Marshes and extends further through Central Russia and especially to the North and the East. — West Slavic settlers reach their new settlement areas through migration from Bohemia and further on to Saxonia and Thuringia, and also through Western Poland to Brandenburg and Mecklenburg-Western Pomerania. — The migration of the South Slavs takes place in two big, yet separate flows, on the one hand through the Moravian Gate to Slovenia, Hungary and Croatia, and on the other hand on the Eastern edge of the Carpathian Mountains to Serbia and Bulgaria.