Czech Land Use and CN analyzer: an open tool for generating CN layers and calculating direct runoff from design rainfall in QGIS
The SCS–CN method is one of the most widely used hydrological methods in the Czech Republic for estimating direct runoff from precipitation events in small catchments. Its practical application is sensitive to the quality and consistency of input data, in particular land use (LU), soil char-acteristics defined by the hydrological soil group (HSG), and appropriately specified design rainfall. The tool, designed to utilise open data in the Czech Republic as a plug-in for the QGIS GIS platform, automates the preparation of input data and the subsequent SCS–CN analysis. Land use is derived from ZABAGED data in combination with LPIS data. HSG and design rainfall are obtained via download services provided at rain.fsv.cvut.cz.
Web services for the provision of design rainfall
In the field of GIS support for hydrological modelling there has been distinct evolution towards so called web services, which enable the users to obtain necessary input data for modelling in a fast and effective way. With respect to design rainfall data – one of the key component – the deficit has been considerable.