Title : Critical infrastructure vulnerability to climate change: a geospatial analysis
Abstract:
All infrastructure are prone to climate extremes, especially those connected to flooding from extreme precipitation, sea level rise and storm surges. Critical Infrastructure, (CI) are vital to promote economic growth and ensure national security and public health, especially during and after disasters, pandemics and other crisis. Due to their important role for the smooth operation of modern societies, governments often invest high amounts to improve their functionality, durability and sustainability ignoring, however, to build or increase resilience towards climate extremes. Recent flooding disasters due to extreme precipitation (eg. Germany, Netherlands and Belgium in July 2021) have proven that even developed countries are unprotected to large floods and that there is not adequate adaptation towards extreme weather events. Although huge progress has been done regarding flooding management with the development of flood projection maps, in practice they are very complicated and are often outdated and inaccurate. So, there is an urgent need for less complicated approaches for vulnerability assessment to flooding events from climate extremes, which could be commonly used by all stakeholders and decision makers.
Geospatial data could contribute to the definition of “vulnerability zones” for each climate hazard. The elevation and the distance from water masses, which could generate flooding events after climate extremes, are key elements in geospatial analysis of vulnerability to climate hazards. More specifically, when assessing CI vulnerability to sea level rise and storm surges, two factors should be taken into account: (i) the distance from the shoreline and (b) the elevation from the sea level. Similarly, the vulnerability assessment to extreme precipitation requires primarily (i) the distance from water masses, such as rivers and/or lakes, and then (ii) the elevation of the assets in relation to the elevation of the water masses. Despite adaptation measures may reduce significantly the level of vulnerability, there is lack of evidence regarding the CI and thus it should not be used in the vulnerability assessment procedure, as it could give inaccurate results.
A retrospective analysis of past extreme climatic events has concluded that elements that lay at a distance varying between 1- 3km and elevations up to 3m, are very exposed to sea level rise and storm surges. For the low-laying regions, all infrastructure built in the zone of approximately 15km from the coastline and elevation 3m are also considered very vulnerable. Similarly, CI built close to rivers/lakes at distances smaller than 1km, face extreme vulnerability to flooding from river/lake overflow, due to extreme precipitation. Riverine flooding is more extensive at sharp “U” of the rivers and inundation may extent to approximately 3km-4km, when the land elevation is lower or close to the river elevation. Riverine flooding is very often enhanced by Creeks or smaller streams that are connected to the main river and may cause inundation deeper than 3m.
Despite the several flooding projection maps, they are inadequate in accurate vulnerability assessment, so the need for mapping the vulnerability through the development of “vulnerability zones” based on specific geospatial metrics, could contribute to more efficient flooding management. Knowing a-priori the “vulnerability zone” each asset lays in, could facilitate decision making for existing and future infrastructure and contribute to the prioritization of the needs for adaptation and resilience financing and investment.
