erosion

Some aspects of catchment protection upstream of future reservoirs

Protected areas of natural water accumulation have been long monitored and protected. So far, little attention has been paid to the catchment area which will be the future source of water for these water reservoirs from the point of view of influencing their quality. This article focuses on certain diffuse (non-point) processes that may lead to pollution and thus to limited use of accumulated water. It describes the methodology for identifying critical points in the vicinity of the future reservoir, where an excessive amount of sediment loads will enter the aquatic envi-ronment during torrential rainfall events. This will lead to sedimentation of the reservoir as well as to the input of dissolved pollutants. The methodology was applied to all 61 selected sites; the results are clearly presented in Tab. 1 and further discussed. As another non-point aspect, the representation of so-called Nitrate Vulnerable Zones within the reservoir catchment areas is evaluated. Although these areas are assessed in terms of excessive nitrate levels in water, other undesirable compounds used in agriculture may also occur there. As a third aspect, the article describes the status of the land consolidation process in the monitored catchments and discusses their contribution to catchment protection. In conclusion, it is stated that it would be necessary to enshrine into legislation the protection of LAPV catchments, especially for those reservoirs intended for drinking water supply.

Verifying the applicability of methods for modelling erosion and connectivity of sediments in the Slavíč catchment in the Moravian-Silesian Beskydy mountains based on geomorphological mapping of fluvial processes

As part of the research activities of the Hydrology Department of CHMI Ostrava, field investigations and measurements are being carried out in several catchments to verify the outputs of GIS tools, empirical formulas, and mathematical models focused on surface runoff, fluvial erosion, and sediment transport. The main emphasis is placed on the influence of deforestation and land use changes on rainfall-runoff relations and fluvial erosion, especially within the framework of the NAZV “DEFOREST” and “CLIMCFOR” projects, in which CHMI collaborates with the Forestry and Game Research Institute (VÚLHM), the Bishopric of Ostrava-Opava, and Water Management Development, and Construction joint stock Company (VRV). The presented article deals with the possibilities of analysing fluvial processes and disconnectivity of flows in the Slavíč catchment in the Moravian-Silesian Beskydy Mountains. ESRI ArcGIS and GRASS GIS tools were used for these analyses. Field verification of outputs took place at several sampling points within the main stream Slavíč.