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Modeling hydrological response of the catchment to various precipitation events
ŠVANDA, Dominik
This thesis deals with the simulation of the hydrological response of a river basin to various precipitation events. The hydrological response was simulated in the Olešenský brook basin. The outflow of water from the landscape is influenced by many different factors at the same time. Among the most important factors are, for example, the slope of the terrain, land use, saturation of the soil profile withwater, anthropogenic influences, vegetation cover and last but not least the geological and soil conditions, the shape and area of the river basin, climatic conditions etc. explained and described in detail. Several methods are used to calculate the water runoff from the landscape, in which case the CN curve method was used to calculate the direct runoff from the landscape. By using the BPEJ map, land use and maximum daily precipitation totals with a probability of repeating N years (2, 10, 20, 50 and 100 years) obtained from the rainfall station Týn nad Vltavou, calculations were performed first in a numerical (vector) way and then the maps of direct water runoff from the catchment area were created in a raster way performed in ArcMap software. In the next step, various scenarios were simulated that influenced the outflow of water from the catchment. The first scenario was a change in soil saturation with water, resp. water content in the soil (dry, medium and wet). It has been found that the outflow of water from the basin and the peak flow were both fundamentally changed. Second scenario was grassing of all arable land in the basin, where the actual state compared to the theoretical state. This change reduced the CN curve values, what in turn reduced the direct water runoff from the landscape. Third and the last scenario was the concept of 20 metres wide infiltration strips along roads, watercourses and water areas. The proposed measure reduced the runoff coefficient values by about 1 % compared to the runoff coefficients at the actual state. In this case, there was no fundamental change as the strips occupy only a small part of the total area. However, infiltration strips still have a positive effect on rainfall-runoff events in the landscape.
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