Abstract

This article deals with the analysis of engineering-geological zones, flood lands and radon hazard. The main reason of the study is the insufficient use of engineering-geological data for land planning and designing activities of competent authorities. The applied method makes use of the possibilities of geographical information systems, terrain research, documentation and study of archives. The research is localized in the selected area of the city of Ostrava affected by former mining of black coal. An appreciable factor for the characterization of engineering-geological conditions in the monitored areas is an analysis of potential flooding of the current and future development. The potential danger characterized by the 100-years flood concerns 5.2% of the studied area, while 18.1% of this area is currently built up and the rest are fields and meadows (28.3%) and forests (24.8%). This implies that neither people nor state administration respected the natural conditions in the interest area. For future developers, investors, building offices, it is also important to pay more attention to the radon hazard because of health safety for the future users of the environment. It can be orientation determined, based on the radon hazard maps that can be used along with other specific purpose maps, especially the map of engineering-geological zoning for the foundation engineering needs. The significance of the radon hazard evaluation in the form of maps permits consideration of this geo-factor further during the selection of places of future constructions. In the study area there are two categories of radon index, that is, one is medium and one transient, while the medium category is bound to the indiscriminate flysch sediments zone and the rest falls in the category with a transient radon index. Based on the observed orientation map category, vital attention must be paid to the implementation of measures preventing radon leaks from the bedrock (special insulation of foundations, etc.).

Key words: Engineering-geological zones, flood lands, radon hazard, mining area, landscape planning, geographical information systems (GIS).