Global assessment of storm disaster-prone areas

Abstract

Background Advances in climate change research contribute to improved forecasts of hydrological extremes with potentially severe impacts on human societies and natural landscapes. Rainfall erosivity density (RED), i.e. rainfall erosivity (MJ mm hm-2 h-1 yr-1) per rainfall unit (mm), is a measure of rainstorm aggressiveness and a proxy indicator of damaging hydrological events. Methods and findings Here, using downscaled RED data from 3,625 raingauges worldwide and log-normal ordinary kriging with probability mapping, we identify damaging hydrological hazard-prone areas that exceed warning and alert thresholds (1.5 and 3.0 MJ hm-2 h-1, respectively). Applying exceedance probabilities in a geographical information system shows that, under current climate conditions, hazard-prone areas exceeding a 50% probability cover ~31% and ~19% of the world’s land at warning and alert states, respectively. Conclusion RED is identified as a key driver behind the spatial growth of environmental disruption worldwide (with tropical Latin America, South Africa, India and the Indian Archipelago most affected).

Flood and Landslide Damage in a Mediterranean Region: Identification of Descriptive Rainfall Indices Using a 40-Year Historical Series

“…In addition to the feared effects of climate change, in terms of supposed extreme exacerbation confirming the so-called "wet-gets-wetter and dry-gets-drier" paradigm, in which most regions which are expected to be wetter, and dry regions drier [7], the urbanization of areas prone to either landslides or floods can play an important role in worsening the situation. Concerning landslides, rapid urbanization, especially in developing nations, will put more people in the path of landslides, and informal housing practices such as uncontrolled slope cutting can increase the chances of landslide occurrences [8].…”

“…Because of their extremely different mechanisms, destructive power, and possibilities of forecasting and prevention, floods and landslides are analyzed separately in the scientific literature. Articles that focus on a single type of phenomena-floods or landslides-are the majority, while papers analyzing their simultaneous occurrence during DHEs are quite rare [7,10]. Actually, to plan effective defensive strategies from DHEs, it cannot be ignored that rainfall events simultaneously trigger landslides and floods, and frequently flood impact is even amplified by simultaneous storm surges [11].…”

“…Indicators and indices represent successful tools for decision making and are often utilized to reduce the communication gap between the scientific community, decision makers, and the population at risk [7]. Indicators and indices are frequently used as synonyms, although they have different meanings.…”

“…The main merit of the indicators is to summarize large amounts of detailed localscale territorial data into a synoptic view that is more easily comparable to data about other features characterizing the same territory. In the natural-hazard literature, indicators and indices are used as tools to assess and summarize risk, vulnerability, exposure, and other aspects related to disaster management [7,16,17]. In the literature, several studies are present regarding rainfall indices, particularly about extreme events and their eventual trends in the Mediterranean basin, which is considered a hotspot of climate change.…”

“…Moreover, in order to provide useful tools supporting national risk-mitigation policies, ISPRA elaborated sets of indicators which summarize at the national scale the landslide and flood risk mapped at municipal scale in the Piano di Assetto Idrogeologico (PAI, River Basin Plans, www.isprambiente.gov.it, accessed on 21 July 2023). Similarly, Donnini et al [7] introduced indicators at the municipal level to differentiate Italian territories based on the spatial distribution of landslides, thus supplying a picture of slope-instability severity that can be used to support decision makers to evaluate and manage landslide-mitigation activities. Moreover, concerning DHEs, several indices have been introduced to assess and compare their severity [1,13], such as the index of damaged area, which is the sum of the area of damaged municipalities divided by the area of the region and the number of victims [1,21,22].…”