Changes in flood damage with global warming in the east coast of Spain

Abstract

Abstract. Flooding is one of the main natural hazard in the world and causes huge economic and human impacts. Assessing the flood damage in the Mediterranean region is of great importance, especially because its large vulnerability to climate change. Most past floods affecting the region were caused by intense precipitation events, thus the analysis of the links between precipitation and flood damage is crucial. The main objective of this paper is to estimate changes in the probability of damaging flood events with a global warming of 1.5, 2 and 3 °C above preindustrial levels and taking into account different socioeconomic scenarios in two western Mediterranean regions, namely Catalonia and the Valencian Community. To do this, we analyse the relationship between heavy precipitation and flood damage estimates from insurance datasets in those two regions. We consider an ensemble of seven regional climate model simulations spanning the period 1976–2100 to evaluate precipitation changes and to drive a logistic model that links precipitation and flood damage estimates, and thus to derive statistics under present and future climates. Furthermore, we incorporate population projections based on 5 different socioeconomic scenarios. The results show a general increase in the probability of a damaging event for most of the cases and in both regions of study, with larger increments when higher warming is considered. Moreover, this increase is higher when both climate and population change are included. When population is considered, all the periods and models show a clearly higher increase in the probability of damaging events, which is statistically significant for most of the cases. Our findings highlight the need for limiting the global warming as much as possible, as well as the importance of including variables that consider change in both climate and socioeconomic conditions in the analysis of flood damage.

Convective precipitation trends in the Spanish Mediterranean region

“…A similar situation occurs in the Aitana mountain range, in the CHJ, where 18% of the annual precipitation has a 5-min intensity rate is greater than 35 mm/h, which is the threshold used to define convective precipitation, reaching 35% in September. However, the role of the Coastal mountain range is very important, since it encourages the most violent precipitation phenomena, with high intensities throughout the entire episode, usually causing sudden surface water floods and flash floods (Llasat et al, 2016: Cortès et al, 2019. In particular, it is no surprise that in some summer months more than 90% of the events are convective.…”

“…The increase in convective precipitation might not be detected in the maximum daily precipitation, since it is usually related to short episodes in which the precipitation amount is less than 100 mm. In this sense, Cortès et al (2019) selected the threshold of 40 mm as the minimum precipitation for flash floods in the study region, showing that the precipitation caused by these events will increase in the future.…”

“…Floods in Central Europe have increased mainly in the summer, and the authors consider that thermodynamic conditions play a major role at present, favouring the feeding of convective processes. Although they have only taken into account river floods and not flash floods in ungauged catchments (those included in the papers by Llasat et al, 2013 andCortès et al, 2019), they also find an increase in the Mediterranean that is associated with an increase in evaporation and convective activity. The present paper is good proof of this increase in convective precipitation.…”

Floods evolution in the Mediterranean region in a context of climate and environmental change

“…On the other hand, a reduction of peak discharges in the Guadalquivir basin (less precipitation and more evapotranspiration) is clear, and the events with a return period of 2 years will be less frequent in the future in the Guadiana and Guadalquivir rivers. Cortès et al (2019) show changes in the probability of flood damage in eastern Spain (specifically in the autonomous communities of Catalonia and Valencia) as a result of global warming of 1.5º, 2º and 3º C above pre-industrial levels and bearing in mind different population scenarios. The model uses a set of seven regional climate model simulations from the EURO-CORDEX project (Jacob et al, 2014), and considers 5 different socioeconomic scenarios that include projections of population, urbanization and Gross Domestic Product on a global and national scale (O 'Neill et al, 2014).…”

Actas del XIX Congreso de Tecnologías de la Información Geográfica. TIG al servicio de los ODS Zaragoza, 12 a 14 de septiembre de 2022

“…El cambio climático está jugando también un papel especialmente relevante, por sus implicaciones ambientales en relación con la alteración creciente de las condiciones térmicas y pluviométricas, materializada sobre todo en un incremento de la temperatura, de la duración e intensidad de las sequías y de la torrencialidad las lluvias (MEDECC, 2019;Cortés et al, 2019;Camarasa, 2020;Olcina, 2020;Blöschl et al, 2020;Ollero et al, 2021;. Kampf et al (2018) y Martínez-Salvador et al (2021) resaltan también la importancia de conocer los umbrales necesarios para generar los flujos de avenida, por su aplicabilidad en modelizaciones hidrológicas predictivas y en la determinación y cartografía de áreas con peligro de inundabilidad.…”