One of the principal challenges for cities on the Mediterranean coast is the management of urban runoff after episodes of intense rainfall. This problem is aggravated by the effects of climate change, with the increase in the frequency and intensity of extreme weather phenomena in this region. In light of this situation, the local governments, in collaboration with the concessionaire companies providing supply and sewage services, are committed to adopting measures aimed at a more efficient management of non-conventional water resources. Examples of good practice for reducing urban flood risk and adapting to climate change are those actions developed in the tourist municipalities of Alicante, Torrevieja, and Benidorm, where measures have been implemented or have been planned and integrated with green spaces, with a commitment to sustainability, such as sustainable urban drainage systems (SUDS) or Nature-Based Solutions (NBSs). This study analyses these case studies, based on a detailed review of the technical projects that contemplate each of the actions. Furthermore, several field trips were made with technical personnel who are familiar with the measures adopted. The results show that the implementation of these systems contributes to advancing the reduction of urban flood risk and the adaptation to climate change, creating more resilient and safer urban spaces for the citizens residing in them.

The management of runoff during torrential rainfall events is a significant problem in urban areas of southeast Spain. The increase in soil sealing and the occupation of areas prone to flooding have aggravated this problem. Due to this situation, municipal administrations, in collaboration with the concession holder for the supply of water and sewage services, Hidraqua Gestión Integral de Aguas de Levante SA, are committed a more efficient management of non-conventional water resources. An example of this can be found in the municipalities of Rojales, Daya Nueva, and San Fulgencio. These towns are located in the Bajo Segura region of the province of Alicante, where various initiatives have been implemented that break away from the traditional paradigm of rigid infrastructures. These initiatives include green spaces or areas, and sustainable urban drainage systems (SUDS) or nature-based solutions (NBS). This article presents various case studies. Firstly, in the town of Rojales, where several actions are being undertaken to improve the management of wastewater and rainwater and provide a solution to unauthorised dumping, as well as encouraging the use of reclaimed water with the creation of a recreational green area, El Recorral Park. Secondly, in the case of Daya Nueva, the Europa Park constitutes a recreational green area, Europa Park, facilitates runoff drainage by SUDS and NBS. Finally, the creation of a floodable pond in the municipality of San Fulgencio encourages the use of wastewater, thus avoiding the discharge of this non-conventional water resource into the sea. In addition, the pond facilitates the appropriate management of runoff water. The working method in this article has been twofold: firstly, bibliographical references have been consulted from other national and international areas; and secondly, the technical projects in the case studies have been analysed in detail. Several field trips have been made to the selected municipalities, accompanied by the technical personnel in charge of the execution of the projects, to examine the measures adopted. The results show that the implementation of these systems contributes to adapting to climate change and creates more resilient urban spaces.

Las proyecciones climáticas y estudios llevados a cabo muestran a la cuenca mediterránea como una región muy afectada por los efectos del calentamiento global. Con este trabajo se pretende conocer mediante una revisión bibliográfica cuales están siendo los principales efectos observados en las precipitaciones, temperaturas y fenómenos extremos en la fachada mediterránea de la península ibérica, y hasta qué punto el mar Mediterráneo está contribuyendo a ese cambio en las condiciones climáticas. Los resultados han mostrado que existen ciertas variables climáticas, como las noches tropicales y las precipitaciones intensas, que en las últimas décadas están aumentando en el área de estudio. La razón se debe a varios factores, aunque el continuo incremento de la temperatura superficial del mar Mediterráneo parece que está jugando un papel diferenciador contribuyendo a la “mediterraneización” de esta región.

The precipitation in the Mediterranean region, characterised by its annual variability and concentration in high-intensity events, is a key factor in territorial planning and the management of runoff in urban areas, particularly on the Spanish Mediterranean coast. This study focuses on the province of Alicante, applying the “daily precipitation concentration index (CI)” in 26 meteorological stations for the period 1981–2020, with the aim of analysing the statistical structure of precipitation on an annual scale. It measures the irregularity and intensity of precipitation according to the concentration of most of the annual total in a few days. Furthermore, it examines the synoptic situations and trajectories of the air masses on days of torrential rain using the HYSPLIT model. This is essential to identify the origin of moist air masses, to understand the meteorological mechanisms that intensify extreme rainfall events, and to identify recurrent patterns that explain their frequency and characteristics. The results reveal extreme CI values of between 0.58 in the interior of the province and 0.71 in the southern pre-coastal area, with a value of 0.68 in the city of Alicante. On average, the CI is 0.65, indicating that 25% of days with more rain have a concentration of around 75% of total precipitation, while 10% of the days represent 45% of the total. With respect to the origin of air masses, the most relevant in the mid-troposphere (500 hPa) are those from the north of Africa, particularly during the final periods of their trajectory, with flows from the east on the surface.

Cartografías para la acreditación del riesgo de inundaciones: SNCZI y PATRICOVA en la Comunidad Valenciana (España)