ZABAGED | VTEI

Czech Land Use and CN analyzer: an open tool for generating CN layers and calculating direct runoff from design rainfall in QGIS

Ing. Josef Jehlička, Ing. Martin Landa, Ph.D. and doc. Ing. Petr Kavka, Ph.D. – 2/2026

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.

Where does a settlement end? Defining urban areas for more than just runoff analyses

Ing. Luděk Strouhal, Ph.D. and doc. Ing. Petr Kavka, Ph.D. – 4/2025

The article presents a methodology for the spatial delineation of significant urban areas in the Czech Republic, primarily for the purposes of hydrological analyses and flash flood risk assessment. First, the definition of urban areas was refined in relation to existing terminology, followed by the development of a comprehensive procedure for creating layers of urban and natural features using the planimetric layers of the Fundamental Base of Geographic Data of the Czech Republic (ZABAGED®) supported by additional open data sources.