Flood Risk Evaluation in Ungauged Coastal Areas: The Case Study of Ippocampo (Southern Italy)

Abstract

The growing concentration of population and the related increase in human activities in coastal areas require numerical simulations to analyze the effects of flooding events that might occur in susceptible coastal areas in order to determine effective coastal management practices and safety measures to safeguard the inhabited coastal areas. The reliability of the analysis is dependent on the correct evaluation of key inputs such as return period of flooding events, vulnerability of exposed assets, and other risk factors (e.g., spatial distribution of elements at risk, their economic value, etc.). This paper defines a methodology to assess the effects of flooding events associated with basin run-off and storm surge in coastal areas. The assessment aims at quantifying in economic terms (e.g., loss of assets) the risk of coastal areas subject to flooding events. The methodology proposed in this paper was implemented to determine the areas subject to inundation on a coastal area in Southern Italy prone to hydrogeological instability and coastal inundation. A two-dimensional hydraulic model was adopted to simulate storm surges generated by severe sea storms coupled with intense rainfalls in order to determine the areas subject to inundation in the low-land area along the Adriatic coast object of this study. In conclusion, the economic risk corresponding to four different flooding scenarios was assessed by correlating the exceedance probability of each flooding scenario with the potential economic losses that might be realized in the inundated areas. The results of the assessment can inform decision-makers responsible for the deployment of risk mitigation measures.

Evaluation of Design Storms and Critical Rainfall Durations for Flood Prediction in Partially Urbanized Catchments

“…Furthermore, because of a strongly interconnected rainfall-runoff process, as well as a rapid advancement of computational technology and the availability of high-resolution topographic data [3], pluvial floods are now simulated using integrated hydrological-hydraulic methods consisting of time-dependent 2D models and so-called rain-on-grid approaches [2,[4][5][6][7]. However, a reliable flood prediction in small ungauged catchments remains difficult because of the lack of field observations needed to calibrate models [8][9][10][11].…”

The Assessment of Urbanization Effect and Sustainable Drainage Solutions on Flood Hazard by GIS

“…For example, Apollonio et al 2020 stated that the reliability of flood risk assessment depends on key inputs such as the return period and the spatial distribution of elements. Accordingly, they distributed element structures, infrastructure as input, buildings, other structures, roads, and specialized/unspecialized land use as output [37]. In this study, a similar assumption was accepted.…”

An Overview of Flood Risk Analysis Methods

“…South America (5%) [37][38][39][40][41] and Africa (4%) [42][43][44][45][46] showed less research interest (Figure 2). Following a detailed analysis of each region, we found that the most researched areas were: the United States, representing 13.19% of the total articles analyzed and 71.72% of the articles located in North America [47][48][49]; the United Kingdom, with 90 articles representing 17.92% of the articles in Europe and 6.78% of the total papers [50][51][52]; Italy and Spain, accounting for 5.27% of the entire articles and 13.94% of the scientific papers published in Europe, respectively [53][54][55]; and China, accounting for 5.27% of the total articles and 20.11% of the articles in Asia [56][57][58]. A significant percentage of publications also came from India, representing 16.6% of all Asian scientific articles and 4.37% of the total publications [59][60][61].…”