Abstract: Coastal zones have always been preferential areas for human settlement, mostly due to their natural resources. However, human occupation poses complex problems and requires proper management tools. Numerical models rank among those tools and offer a way to evaluate and anticipate the impact of human pressures on the environment. This work describes the preliminary implementation of a 3-dimensional computational model for the coastal zone in Sines, Portugal. This coastal area is under significant pressure from human activities, and the model implementation targets the location of a fish aqua-culture. The model aims to reproduce the hydrodynamics of the system, as part of an ongoing project to simulate the dynamics of the aquaculture area. So far, the model application shows promising results.

Abstract: The Douro is one of the largest rivers of the Iberian Peninsula, representing the most important buoyancy source into the Atlantic Ocean on the northwestern Portuguese coast. The main goal of this study is to contribute to the knowledge of physical processes associated with the propagation of the Douro River plume. The general patterns of dispersion in the ocean and how the plume change hy-drography and coastal circulation were evaluated, considering the main drivers involved: river discharge and wind. Coastal models were implemented to charac-terize the propagation of the plume, its dynamics, and its impact on coastal circu-lation. Different numerical scenarios of wind and river discharge were analyzed. The estuarine outflow is sufficient to generate a northward coastal current without wind under moderate-to-high river discharge conditions. Under easterly winds, the propagation pattern is similar to the no wind forcing, with a northward current speed increasing. A southward coastal current is generated only by strong west-erly winds. Under upwelling-favorable (northerly) winds, the plume extends offshore with tilting towards the southwest. Southerly winds increase the velocity of the northward current, being the merging of the Douro and Minho estuarine plumes a likely consequence.

Abstract: Understanding the impact of sea level rise on coastal areas is crucial as a large percentage of the population live on the coast. This study uses computational tools to examine how two major consequences of sea level rise: salt intrusion and an increase in water volume affect the hydrodynamics and flooding areas of a major estuary in the Iberian Peninsula. A 2D numerical model created with the software MOHID was used to simulate the Guadiana Estuary in different scenarios of sea level rise combined with different freshwater flow rates. An increase in salinity was found in response to an increase in mean sea level in low and intermediate freshwater flow rates. An increase in flooding areas around the estuary were also positively correlated with an increase in mean sea level.

Abstract: The ecosystem function of local fisheries holds great societal importance in the coastal zone of Cartagena, Colombia, where coastal communities depend on artisanal fishing for their livelihood and health. These fishing resources have declined sharply in recent decades partly due to issues of coastal water pollution. Mitigation strategies to reduce pollution can be better evaluated with the support of numerical hydrodynamic models. To model the processes of hydrodynamics and water quality in Cartagena Bay, significant consideration must be dedicated to the process of light attenuation, given its importance to the bay’s characteristics of strong vertical stratification, turbid surface water plumes, algal blooms and hypoxia. This study uses measurements of total suspended solids (TSS), turbidity, chlorophyll-a (Chl-a) and Secchi depth monitored in the bay monthly over a 2-year period to calculate and compare the short-wave light extinction coefficient (Kd) according to nine different equations. The MOHID-Water model was used to simulate the bay’s hydrodynamics and to compare the effect of three different Kd values on the model’s ability to reproduce temperature profiles observed in the field. Simulations using Kd values calculated by equations that included TSS as a variable produced better results than those of an equation that included Chl-a as a variable. Further research will focus on evaluating other Kd calculation methods and comparing these results with simulations of different seasons. This study contributes valuable knowledge for eutrophication modelling which would be beneficial to coastal zone management in Cartagena Bay.