In article sensitivity analysis of NRCS-UH model on changes of entrance parameters were made. Influence of precipitation hietogram shape, CN parameter and lag time on changes of Qmax1% flows in uncontrolled catchment were studied. Izwór stream catchment were chosen to analysis. It is typical mountainous and forest catchment - 86% of its surface is covered by forest. All calculation were made with use of HEC-HMS 3.4 program. In NRCS UH model, catchment have been divided into particular catchments, for which a weighted average of CN parameter and also lag time have been evaluated. These parameters were an entrance parameters for further calculations. Influence of changes of parameters size and results got from model were established by changing their size about 10% in comparison to exit values and then simulations were executed. There were assumed that parameters in model will be modify till ±50% of entrance values. Calculations showed that HRCS UH model is most sensible on changes of precipitation hietogram shape and CN parameter, which characterized the retention of catchment. In turn, modify of lag time does not influence in fact on change of maximum flow values.
...
This article shows analyzes the possibility of reducing the 1% frequency flood wave with use of dry storage reservoirs. Analyses were carried out in the Serafa catchment, where due to a very high degree of sealing creates a risk of flooding for residents, which showed even the flood of May 2010. The increase in the degree of sealing due to faster response to the rainfall catchment area and, consequently, higher peak flows. An alternative to increase the degree of sealing the catchment are measures to improve water retention. One such method is the construction of dry storage reservoirs. In this article was analyzing the work of these variants reservoirs - in the first scenario assumed a reservoir on the Serafa river, in the second - two dry reservoirs, one on the outlet in Malinówka tributary and second - as in variant I. The capacity of the reservoirs resulted from the anal-ysis of topographic maps and digital terrain model and the small retention program for the Malopolska Voivodeship. All calculations were carried out in the HEC-HMS. In the case of the analyzed catchment was the most preferred variant II. Calculations showed that this variant is possible to reduce the maximum ...
