Pluvial flooding in urban areas across the European continent

Abstract

Pluvial flooding is a result of overland flow and ponding before the runoff enters any watercourse, drainage system or sewer, or cannot enter it because the network is full to capacity, usually caused by intense rainfall. River and coastal floods get the most attention since they are largest and last the longest, while pluvial floods are relatively marginalized in research. Therefore, the main goal of this research was to show risk posed by pluvial floods, their connection to current global climate change processes, present effects of flooding in European cities, as well as what we can expect in the future. Furthermore, the aims were to present and get more familiar with scientific projects, strategies, directives and measures devised both on national and international levels, that deal with urban pluvial flood issues across the European continent. Climate change projections indicate that there will be an increase in the frequency and intensity of rainfall events throughout Europe and along with ongoing urbanization, the problem of pluvial flooding will most certainly require more attention, which it is starting to receive. Some countries have already developed their strategies and initiatives and implemented both structural and non-structural measures, such as spatial planning, constructional measures, information systems, reducing land sealing through policies, building codes and standards, on-site improvement of retention, infiltration, evaporation, and rainfall water recycling with the use of green roofs, permeable or porous pavements, rain gardening or urban rainwater harvesting. At the same time, there are numerous research papers, studies, conferences and workshops devoted to the problem of pluvial flooding and its management carried out in an attempt to properly deal with this hazard.

Impact of Climate Change on Extreme Rainfall Events and Pluvial Flooding Risk in the Vojvodina Region (North Serbia)

“…Similar to the results of this study, numerous other studies across Europe indicate that future climate change is expected to intensify heavy rainfall events and pluvial floods, with projections suggesting an increase in both the frequency and intensity of these events [55]. These changes are confirmed to escalate under various climate scenarios (RCP 4.5 and RCP 8.5), emphasizing the growing challenge of pluvial flooding, which will require greater attention [56,57]. Additionally, analyses predict a 47% rise in flood volumes for 10-year events and nearly a doubling of flood frequency, turning what was historically a 5-year event into a 2-year event [58].…”

Urban expansion of the largest cities in Bosnia and Herzegovina over the period 2000-2018

“…The data demonstrate, moreover, how artificial patches and barriers fragment landscape more and more, endangering thereby biodiversity and decreasing green surfaces (Hardi et al, 2020). Urbanization with an increase of non-permeable surfaces and lack of natural drainage created additional flooding issues that did not previously exist and that never before there had been so many human assets that were in the way of floods like today (Prokić et al, 2019).…”

Flood Risk in Urban Areas: Modelling, Management and Adaptation to Climate Change. A Review

“…While river floods have been extensively analyzed in recent years, following the implementation of various floods directives (such as the EU Floods Directive 2007/60/CE), far less attention has been paid to pluvial flooding [143], probably because this type of flooding is much more complicated to evaluate and forecast than river flooding. Numerical models for pluvial flooding that consider the interaction between the surface runoff and the sewer network, although currently available for practical applications [84,86,[93][94][95]144], are more complex than river-flood models, and the required input data are more comprehensive (including the capacity and location of drain inlets, manholes, sewers, and other data about the sewer network that in the majority of urban settlements are not available).…”