Flood maps and their potential role in local spatial planning: A case study from Slovakia

Abstract

The article is focused on the creation of flood maps for ungauged basins (i.e. local spatial scale areas), using a hydrologic-hydraulic approach, geographic information systems (GIS) and remote sensing techniques, and their role in local spatial planning. The case study is represented by the Turniansky potok catchment which was not mapped in the preliminary flood risk assessment (EU Floods Directive) as an area with existing potential risk. The design discharges were estimated by applying the regional formula. The design discharge with 100-year return period was chosen for hydraulic modeling using the one-dimensional HEC-RAS model. The basis for creating the flood vulnerability map for the selected hydraulic domain was the current land use. Each land use category was assigned a category of acceptable risk (low, medium, high). Furthermore, the vulnerability was defined by digitizing buildings within the hydraulic domain. The role of the created flood maps, as regulatory tools in local spatial planning (i.e. local development plan of municipality), was highlighted and discussed. The importance of flood maps is primarily seen in limiting the irresponsible expansion and densification of construction in the areas near the watercourse which were assigned the low acceptable risk.