Possibilities of the semi-distributed and distributed models in forest hydrology on example of the Ostravice basin

The impact of forest on the rainfall-runo conditions and erosion processes is of- ten discussed in both scienti c papers and land planning issues. Long-term stud- ies of rainfall-runo conditions and erosion processes in small forest catchments are a traditional approach to study of these landscape relations. But several aspects give a support to the usage of geographic information systems (GIS) and numerical hydrologic models -- rainfall-runo , hydrodynamic and dynamic erosion models. Using this ensemble on larger areas beyond the spatial extent of a small forest wa- tershed is one of them. The possibility of long-term simulations and prediction of the future runo and erosion conditions is the second main reason for using these analysis tools. Using capabilities of the GIS and numerical models is the approach demonstrated on the Ostravice basin and real hydrosynoptic situations. Several rainfall-runo episodes were selected -- common regional rainfalls with low ante- cedent watershed saturation and convective ash rainfall with higher watershed saturation. The results, which were achieved by the utilization of various meth- ods of the hydrologic transformation in the watershed scale (Horton, Green-Ampt, SCS-CN) and semi-distributed (HYDROG, HEC-HMS) and distributed models (SIMWE, MIKE SHE) con rm the in uence of forest land cover on the rainfall- runo relations. Final testing of the model results illustrates a good correspond- ence of the semi-distributed and distributed models.