Pluvial Flash Flood Hazard and Risk Mapping in Croatia: Case Study in the Gospić Catchment

Abstract

Since the beginning of the 21st Century, Europe has been affected by destructive floods. European Union Member States have an obligation to develop flood hazard and flood risk maps as support to the Flood Risk Management Plan (FRMP). The main objective of this study is to propose a methodological framework for hazard and risk assessment of pluvial flash floods in Croatia at the catchment level, which can be integrated into the FRMP. Therefore, a methodology based on the source–pathway–consequence approach for flood risk assessment is presented, which complies with the EU Floods Directive. This integrated and comprehensive methodology is based on high-resolution open data available for EU Member States. Three scenarios are defined for a low, medium, and high probability, defined by design storms of different durations. The proposed methodology consists of flood hazard analysis, vulnerability assessment, and risk analysis. Pluvial flash flood hazards are analyzed using a 2D hydrologic–hydraulic model. The flood vulnerability assessment consists of a GIS analysis to identify receptors potentially at risk of flooding and an assessment of susceptibility to potential flood damage using depth–damage curves. Flood risk is assessed both qualitatively in terms of risk levels and quantitatively in terms of direct damages expressed in monetary terms. The developed methodology was applied and tested in a case study in the Gospić catchment in Croatia, which surrounds a small rural town frequently affected by pluvial flash floods.

Kilometer-scale trends, variability, and extremes of the Adriatic far-future climate (RCP 8.5, 2070−2100)

“…Changes in timing and intensity of rainfall events could lead to increased risk of droughts or floods in different parts of the region. Precipitation extremes in the Adriatic region are a subject of interest and concern due to their impact on the environment, society, and economy (Krvavica et al, 2023). Droughts pose serious threats to agriculture, water resources, and ecosystems.…”

Pluvial Flood Susceptibility in the Local Community of the City of Gospić (Croatia)

“…The city of Gospić (Figure 1) is located at 44° N latitude and 15° E longitude in the central part of the Lika river basin [7]. Gospić, with a population of around 11,464 residents [19], exhibits a blend of land use patterns featuring a predominantly rural landscape (agriculture and forestry).…”

“…The issue is most pronounced in urban areas with insufficient urban drainage systems and a high percentage of impervious surfaces. European regions are experiencing an increased frequency of PF, and examples of multiple-affected cities are the city of Rome [3], Palermo [4], Poreč [5], Pariz, London, Berlin [6], and Gospić [7]. PF is called an ʹinvisible hazardʹ because it can occur in areas far removed from water bodies, where flooding is not typically expected [2].…”

Integrating Geographic Information Systems and Hydrometric Analysis for Assessing and Mitigating Building Vulnerability to Flash Flood Risks

“…Regarding flash flood hazard assessment, it can be measured both qualitatively based on risk categories and quantitatively in the form of financial direct losses [20]. In Japan, flooding area data have been accessible since 1993; nevertheless, no research has used these records to investigate the generation processes in urban pluvial flooding [21].…”