Social Perception of Geo-Hydrological Risk in the Context of Urban Disaster Risk Reduction: A Comparison between Experts and Population in an Area of Southern Italy

Abstract

The perception of risk is influenced by how the signals about impacts of events are collected, selected, and interpreted. Empirical data suggest that significant differences in the perception of risk occur within the non-expert population itself, as well as between experts and non-expert population. The paper seeks to examine the risk perception of citizens living in an area subject to high hydro-geological risk of Calabria (Southern Italy), and understanding if local policy makers are aware of how local residents perceive risk. Quantitative and qualitative methods were employed to analyze the perception of experts, stakeholders and citizens on the following research topics: (i) perception of geohydrological risk, involvement in past events and behavior exhibited; (ii) information, communication, preparedness, and feeling of safety and trust. The results of the survey showed the communication gap between experts and people, evidencing the need for local authorities and experts to disseminate the culture of awareness on the risk and to increase the safety level of the citizens by means of participated actions aimed at reducing urban disaster risk.

Pre-Disaster Retrofit Decisions for Sustainable Transportation Systems in Urban Areas

“…Equation (8) is tenable at this point. As shown in Table 10, the ratios of travel time for the minimum impedance path of post-disaster to pre-disaster between OD pairs (17,13) and (19,20) are less than the time reliability coefficient γ t 0.8. Thus, Equation (8) is proved and the travel time reliability constraints are satisfied by the retrofit decision plan.…”

“…For post-disaster connectivity of the transportation system, it is not realistic to verify all OD pairs because of the large scale in this case. OD pairs (2,10), (13,17), and (19,20) are selected for analysis.…”

“…To satisfy connectivity constraints, the pre-disaster retrofit decision plan is supposed to ensure the accessibility between OD pairs, i.e., that there exists at least one valid path between any OD pair under possible disaster scenarios. Combined with Table 7, Table 8 lists connective paths (represented by node numbers) between OD pairs (2,10), (13,17), and (19,20) in disaster scenarios ω 1 , ω 2 , ω 3 , and ω 4 . There are other connective paths between these OD pairs that are not listed in the table.…”

“…It is not realistic to verify travel time reliability constraints of all OD pairs because of the large scale in this case. OD pairs (17,13) and (19,20) are chosen to represent all OD pairs to verify travel time reliability constraints.…”

“…It is necessary to select links [18] of transportation systems for pre-disaster retrofit in order to cope with various disaster scenarios that could occur in disaster risk areas. In a word, for urban disaster risk reduction [19,20] and sustainable development of transportation systems, this paper studies pre-disaster retrofit decisions for transportation systems in urban areas.…”