Morphological variations in subsidence basin and importance for land use planning: undermined Karvina region (Czech Republic)

Abstract

The study area has been greatly affected by mining activities and other anthropogenic activities since it falls within the so-called Ostrava-Karvina Coal District. Morphological variations in time by temporal variations in subsidence basins by underground mining activities in the Moravia-Silesian Region in the north-east of the Czech Republic was investigated in this article. Subsidence was observed in the four time intervals of 1983-1990, 1983-1995, 1983-2000, and 1983-2005. Relationships between estimated subsidence during time period of 2003-2010 and municipality land use plans were identified by overlay analyses. There is a clear impact on the land use plans caused by varying thoroughness of the urban planners. As the result of the observations in these periods, underground mining activities considerably had a negative impact on the current built-up area. Despite this, the built-up area erected on the most affected subsidence interval of “500-1200 cm” during the last time period of 1983-2005 is only 1%. According to the Land Use Plan Categorization, development planned for the most impacted subsidence interval of “500-1200 cm” is in the U_V_0 category of Unspecified Production Zone and also in the U_DL_2 zone of mining interest. This development area covers 1.54% of the overall planned development. Analyses related with slope deformation in the study area imply that there are three active areal shaped slide areas, one so-called other areal shaped slide area (55.6 ha) and three active very small slide areas. A possible risk is posed by the active areal shaped slide areas which have an overall surface area of 12.05 ha. As the main results of this study; it was found that the subsidence distribution implies trends which confirm that the area unaffected by subsidence impacts decreased over time due to the expansion of the subsidence basin, and thus a re-distribution of impacts occurred in the study area. These impacts were caused by black coal mining in the Karvina Mine, the CSA Plant and in allotments of Karvina-Doly I, Doubrava and Darkov. As another result; the analyses showed that impacts of subsidence in the area had not properly considered in the planning of future development.