Volumetric and landscape-ecological diachronic analysis of a historical artificial water reservoir Evička in Slovakia

The present study focuses on the analysis and evaluation of the changes in the retention volume of the water reservoir Evička, the ecosystems of littoral, sublittoral and profundal zone as well as the changes in the land cover of the riparian zone and reservoir basin. The changes in reservoir volume were determined on the basis of a comparison of the actual bottom’s topography, acquired through field surveying with the bottom’s topography from the maps for a 40-year period (1971-2011). The volume of the sediments deposited in the water reservoir Evička for given period is 10917 m^3. The changes in the landscape structures of riparian zone and reservoir basin, identified on the basis of the analysis of aerial measurement pictures, orthophotomap and field survey, were evaluated for the period of 1949-2012, i.e., 63 year. It is evident from the analysis of the landscape structure changes in the whole reservoir basin that the area of developed surfaces increased by 11.2% and the surface area of water reservoir Evička decreased by 1165 m^2 during that period. We interpret these facts as the result of a negative anthropogenic effect, mainly by building activity within the reservoir basin and near the water reservoir. At the same time, the contribution presents possible measures for the management of water reservoir Evička and its surroundings.