The Effects of Sea Level Rise on Salinity and Tidal Flooding Patterns in the Guadiana Estuary

Lara Mills,Flávio Martins,João Janeiro

doi:10.1007/978-3-030-45263-6_2

Abstract

Sea level rise is a worldwide concern as a high percentage of the population accommodate coastal areas. The focus of this study is the impact of sea level rise in the Guadiana Estuary, an estuary in the Iberian Peninsula formed at the interface of the Guadiana River and the Gulf of Cadiz. Estuaries will be impacted by sea level rise as these transitional environments host highly diverse and complex marine ecosystems. Major consequences of sea level rise are the intrusion of salt from the sea into fresh water and an increase in flooding area. As the physical, chemical and biological components of estuaries are sensitive to changes in salinity, the purpose of this study is to further evaluate salt intrusion in the Guadiana Estuary caused by sea level rise. Hydrodynamics of the Guadiana Estuary were simulated in a two-dimensional numerical model with the MOHID water modeling system. A previously developed hydrodynamic model was implemented to further examine the evolution of salinity transport in the estuary in response to sea level rise. Varying tidal amplitudes, freshwater discharge from the Guadiana River and bathymetries of the estuary were incorporated in the model to fully evaluate the impacts of sea level rise on salinity transport and flooding areas of the estuary. Results show an overall increase in salinity and land inundation in the estuary in response to sea level rise.

Highlights

Sea level changeGlobal mean sea level is rising at a rate of approximately 3.2 millimeters per year (Church et al )
The objective of this study is to evaluate the evolution of hydrodynamics and changes in salinity distribution in response to various sea level rise scenarios in a major estuary in the Iberian Peninsula, the Guadiana Estuary
Of relevance are the results of a study by Mills et al ( ) as the present study builds upon the methodologies used to simulate hydrodynamics and changes in salinity distribution with respect to sea level rise

Summary

Introduction

Global mean sea level is rising at a rate of approximately 3.2 millimeters per year (Church et al ). According to the most recent report from the Intergovernmental Panel on Climate Change (IPCC), the rate of global mean sea level rise has been increasing over the last two centuries and continues to accelerate. Sea level rise will affect coastal areas, which should be a concern considering 10% of the world’s population live within 10 m elevation of the present sea level (Carrasco et al ). Direct consequences of sea level rise on coastal areas include an increase in flooding area, an increase in erosion, and an increase in salinity and changes in ecosystems (Nicholls et al ). Of relevance to the present study is the impact of sea level rise on estuaries, where rivers intersect sea and freshwater mixes with saltwater. Effects of sea level rise on estuaries

Objectives

Methods

Results

Discussion

Conclusion