Performance-Based Planning to Reduce Flooding Vulnerability Insights from the Case of Turin (North-West Italy)

Abstract

Climate change impacts urban areas with greater frequency and exposes continental cities located on floodplains to extreme cloudbursts events. This scenario requires developing specific flooding vulnerability mitigation strategies that improve local knowledge of flood-prone areas at the urban scale and supersede the traditional hazard approach based on the classification of riverine buffers. Moreover, decision-makers need to adopt performance-based strategies for contrasting climate changes and increasing the resilience of the system. This research develops the recent Flooding Risk Mitigation model of InVEST (Integrated Evaluation of Ecosystem Services and Trade-off), where cloudburst vulnerability results from the soil’s hydrological conductivity. It is based on the assumption that during cloudburst events, all saturated soils have the potential for flooding, regardless of the distance to rivers or channels, causing damage and, in the worst cases, victims. The model’s output gives the run-off retention index evaluated in the catchment area of Turin (Italy) and its neighborhoods. We evaluated the outcome to gain specific insight into potential land use adaptation strategies. The index is the first experimental biophysical assessment developed in this area, and it could prove useful in the revision process of the general town plan underway.

Mainstreaming climate resilience: A GIS-based methodology to cope with cloudbursts in Turin, Italy

“…Once there was shown to be discrepancies between the predictions, it was necessary to understand these differences. As a starting point, it was assumed that a possible key to model cloudburst vulnerability was to consider the degree of alteration of the natural waterways (Salata et al, 2021). In a highly urbanized environment characterized by vast sealed surfaces, the most vulnerable areas were likely to be those where the difference between the canalization system and the natural one is higher.…”

“…This approach, significantly simplifying the overall planning processes by integrating data visualization techniques with traditional assessment procedures, is theoretically "grounded" on the research work carried out by different authors in various fields. The most important contribution comes from the work on vulnerability assessments through ecosystem services (ES) mapping, investigated in recent years by some authors (Salata et al, 2021). Such studies have pioneered GIS to model the built environment and ES-specific software outputs to measure biophysical performance.…”

“…InVEST is an open-source modelling software suite jointly developed by Stanford University, the University of Minnesota, the Nature Conservancy, and the World Wildlife Fund (Salata et al, 2021). The tool is specially designed for Ecosystem Services assessments and territorial and town planning evaluation, offering a variety of pre-configured models to choose from.…”

Adapting Cities to Pluvial Flooding: The Case of Izmir (Türkiye)

“…In this study, the session was launched using a depth rainfall of 70 mm as the modeling parameter. This value was chosen because it is far less than the values recorded in the rain event of 13-14 November 2020 and significantly more than 50 mm, considered the minimum threshold of "cloudburst" [44]. According to Türkiye's meteorological agency, Meteoroloji Genel Müdürlü g (MGM), between 13 and 14 November 2020, 42.1 mm of rain fell in the town of Menderes during a single rain event.…”

Research Progress of Urban Floods under Climate Change and Urbanization: A Scientometric Analysis

“…For example, China's urbanization rate increased from 10.64% in 1949 to 63.89% in 2020 (see National Bureau of Statistics of China http://www.stats.gov.cn/tjsj/ndsj/#, accessed on 8 March 2021). Urbanization greatly reduces the permeable area of the urban underlying surface, causing a lot of urban rainwater to flow onto the ground or into the artificial drainage system, instead of naturally being infiltrated into the ground and absorbed by the soil [14,15]. When the rainfall exceeds the capacity of the drainage system, especially in some areas with deterioration and insufficiency of the capacity of urban drainage infrastructure and lack of excellent urban planning strategies [16,17], stormwater has no way to go, but must stay on the ground to form urban waterlogging [18,19].…”