Assessment of flood hazard areas at a regional scale using an index-based approach and Analytical Hierarchy Process: Application in Rhodope–Evros region, Greece

Abstract

The present study introduces a multi-criteria index to assess flood hazard areas in a regional scale. Accordingly, a Flood Hazard Index (FHI) has been defined and a spatial analysis in a GIS environment has been applied for the estimation of its value. The developed methodology processes information of seven parameters namely flow accumulation, distance from the drainage network, elevation, land use, rainfall intensity and geology. The initials of these criteria gave the name to the developed method: "FIGUSED". The relative importance of each parameter for the occurrence and severity of flood has been connected to weight values. These values are calculated following an "Analytical Hierarchy Process", a method originally developed for the solution of Operational Research problems. According to their weight values, information of the different parameters is superimposed, resulting to flood hazard mapping. The accuracy of the method has been supported by a sensitivity analysis that examines a range for the weights' values and corresponding to alternative scenarios. The presented methodology has been applied to an area in north-eastern Greece, where recurring flood events have appeared. Initially FIGUSED method resulted to a Flood Hazard Index (FHI) and a corresponding flood map. A sensitivity analysis on the parameters' values revealed some interesting information on the relative importance of each criterion, presented and commented in the Discussion section. Moreover, the sensitivity analysis concluded to a revised index FHIS (methodology named FIGUSED-S) and flood mapping, supporting the robustness of FIGUSED methodology. A comparison of the outcome with records of historical flood events confirmed that the proposed methodology provides valid results.

Assessing Flood Hazard at River Basin Scale with an Index-Based Approach: The Case of Mouriki, Greece

“…FIGUSED-S has been developed by the authors [11] and is an index-based model operating in a GIS environment. FIGUSED-S defines flood hazard areas and originally had a regional focus.…”

“…The main steps in flood risk management are the following [9]: flood planning mitigation measures (before flood), response measures (during flood) and recovery (after flood). Different methods and techniques have been applied, including simulation (e.g., HEC-RAS software package), index methods, statistical analysis and hybrid methods in a geographic information system (GIS) environment [10][11][12]. GIS is recognized as a powerful means to integrate and analyze data from different sources.…”

“…The aim is to define flood hazard zones, where mitigation and protection measures should be prioritized. The developed methodology has been presented in the authors' previous work [11], which was developed aiming to provide flood hazard assessments and mapping at a regional scale. However, an integrated flood protection plan presupposes higher discretization of hazard maps so as to be economically affordable and describable in terms of environmental processes.…”

Analysis of Flood Risk Due to Sea Level Rise in the Menor Sea (Murcia, Spain)

“…Lithology and geomorphology are closely linked with the resistance of the materials, their permeability, texture or alterability [36]. The elevation of the terrain slope and distance factors play a fundamental role as obstacles to the water advance [37], while the coastal factor provides an insight about the evolution trend of the coast line as well as helping to identify coastal hazards [38]. Bathymetry affects the behavior of the waves and as [39] explains, this kind of data helps to improve the coastal management.…”

Landslide Susceptibility Mapping in Vertical Distribution Law of Precipitation Area: Case of the Xulong Hydropower Station Reservoir, Southwestern China

“…The pairwise comparison of the analytic hierarchy process (AHP) is based on expert opinions and thus introduces a degree of subjectivity for the criteria of significance [36]. However, it is sometimes criticized for its subjectivity.…”