GIS and soil property-based development of runoff modelling to assess the capacity of urban drainage systems for flash floods

The extreme precipitation resulting from climate change has been causing increasingly serious damage in populated areas over the past 10–15 years. The torrents of flash floods cause significant financial damage to both the natural environment and man-made structures (such as roads and bridges). The determination of the physical geographic parameters of this phenomenon (e.g. the amount of runoff water) is significantly affected by technical uncertainties, usually due to the lack of monitoring systems. However, the application of modern geospatial tools can improve the quality of input data needed for runoff modelling. In the present study, an existing runoff model (the Stowe model) developed by ESRI was further enhanced with field measurements, soil parameters, GIS, and remote sensing data, resulting in the creation of the model named ME-Hydrograph. Finally, the two models were compared, and we examined the capacity of an urban stormwater drainage system through surface runoff modelling. The aim of the research was to create a runoff model that can be easily and quickly used. The application of this geospatial model presented in the study can be useful not only in the examination of urban stormwater drainage but also in contributing to the understanding and management of flash floods that occur in Hungary. Additionally, it can aid in the development of risk mapping related to flash floods in the country.