Fluvial and Coastal Interactions under Mediterranean Climate Conditions

Water-management issue

Deltaic systems are unique landscapes of a high environmental value in continuous transformation due to the sculpting action of marine and fluvial dynamics. In the last two centuries, the growth of tourism and its occupation for agricultural and industrial activities, has favoured the irrational use of their resources. Sometimes they are also suffering severe erosion problems due to the regulation of their rivers’ flows. Mediterranean deltas such as those at the Guadalfeo and Adra river mouths (Spain) are especially vulnerable to sea level rise, which is one of the most important causes of delta retreat around the globe. Therefore, the present issues found in these systems and the erosion in the adjacent coasts will become aggravated in a climate change scenario that includes sea level rise and changes in the frequency and persistence of storms and precipitation events.
We propose to analyse changes in physical processes such as sea waves, fluvial discharges and sediment transport, that interact and control the dynamics of these zones as well as the integrity of the physical environment and ecologic condition under different climate change scenarios to contribute to the quality and usability of climate services at fluvial, coastal and transition zones of semiarid watersheds in this region.

Temporal and spatial scale

The time scale of the study depends on the specific problem under consideration. The results of this work will focus on time scales of O(1-10 year) for applications such as beach nourishment projects or operational reservoir planning, while flooding studies deal with climate change projections until 2100.

The management of those coastal areas depend on a local delegation of the Spanish ministry with competences in coastal zones (Provincial Coastal Service of Granada and Provincial Coastal Service of Almería) and also on the regional government. The first ones work with spatial scales O(100 m²) in the coast of Granada and Almería while the regional government decision-making process usually includes spatial scales of O(100 – 100,000 km²) in Andalucía in the coastal and fluvial areas.

Climate Indicators

Pan-European and local indicators

Historical and projected data of maritime and hydrological variables such as sea level pressure, sea level height, significant wave height, wave period, wave direction, wind velocities, wind directions, temperature, precipitation, radiation, river flow, reservoir discharges at a local and regional scale in the south of Spain.

Case study workflow

Assessment of needs and applications – Identification of the end-users’ needs and applications of the study. Revision of the state of art of the climate services and variables available for the study at different spatial and temporal scales and the models to develop the methodology. Definition of the indicators needed in the study.

Analysis of coastal and river mouth dynamics – Assessment of the current state of the coastal dynamics in the Gualdalfeo and Adra river mouths. This step includes the use of downscaling and statistical techniques, calibration and validation of numerical models for wave propagation, stochastic analysis and simulation, among others.

Maritime climate projections and impacts – Extraction of projections from the selected European and national Climate Services. Modeling of new variables when needed. Analysis of the trends of the variables and the associated impacts on the coastal area. Development of indicators to assess vulnerability and risk to climate change and its uncertainty.

Development of end-user tools and feedback – Development of user friendly visualization and assessment tools such as erosion maps, flood extent, vulnerability and risk maps to quantify climate change impacts and uncertainties. Discussion with the end-users/clients and inclusion of their feedback into the results presentation.

Recommendations and adaptions – Development of a series of recommendations to climate change adaptation to help end-users in their decision-making processes.

Importance and Relevance of Adaptation

In traditional coastal engineering design, maritime extreme events are quantified by means of the return period of a single variable such as the significant wave height. Different local and regional authorities use climate services with historical data to assess extreme events for flooding and erosion planning but are not currently using climate change projections. This work offers the inclusion of multivariate statistical techniques for long-term climate simulation using an ensemble of projections to assess the uncertainty. Therefore, this study will be a step-forward for the implementation of climate change impacts in the current decision-making processes of local authorities.

Scientific Publications

Planned publication outcomes:

Multivariate statistical model to simulate storm evolution. 36^th International Conference on Coastal Engineering ICCE18. Baltimore, USA.
Suspended sediment dynamics by event typology and its siltation effects in a semi-arid snowmelt-driven basin. 9^th International Conference on Fluvial Hydraulics. Lyon-Villeurbanne, France.
Reservoir sedimentation impact downstream in a semi-arid basin with greenhouses cultivation. 9^th International Conference on Fluvial Hydraulics. Lyon-Villeurbanne, France.
Storm characterization and simulation in the Mediterranean coast of Spain. – In preparation for its submission to Coastal Engineering.
Coastal flooding induced by extreme events including sea-level rise scenarios and their uncertainty. – Journal Paper
Long-term coastal adaptation to climate change in the Mediterranean Coast of Spain. – Journal Paper
Adaptation to flooding events in a climate change scenario in the Mediterranean Coast of Spain – International Conference presentation