|DyEPlume - Estuarine Dynamics and Plume Propagation in the Portuguese Coast – Impacts of Climate Change|
João Miguel Dias
Programme - PTDC/MAR/107939/2008
Execution dates - 2010-06-01 - 2013-05-31 (36 Months)
Funding Entity - Fundação para a Ciência e Tecnologia
Funding for CESAM - 79220 €
Total Funding - 140698 €
Proponent Institution - Universidade de Aveiro
Instituto Superior Técnico (IST)/ Marine Environment and Technology Center (MARETEC)
Estuaries impact the adjacent marine environment through the estuarine plumes, affecting a wide range of physical and biogeochemical variables. Major rivers inject freshwater onto the adjacent shelf where mixing of these river plumes takes place, affecting the transport and transformation of dissolved and particulate materials at the coastal margin. Therefore, extreme events of river discharge associated to torrential rain episodes and to different wind scenarios, affect the balance of these systems (coupled estuary-near-shelf system).
According to recent climate change scenarios presented on 2007 report of the Intergovernmental Panel on Climate Change southern Europe will tend to become dryer despite winter torrential rain events becoming more frequent, increasing freshwater discharges. Consequently, erosion processes and material loads are expected to increase, leading to an aggravation of light-limiting conditions to phytoplankton and consequently to primary production. In coastal regions, changes in wind speed and direction are known to alter turbulence and upwell nutrients to the euphotic layer.
Changes in meteorological patterns can affect these transition systems making them vulnerable to storm-surge events which, in turn, may induce strong currents and unstratify the water column. Sea level rise is also expected to cause changes inside estuaries (intertidal areas), affecting the hydrodynamics of these transition systems.
Given these scenarios, there should be a national interest in addressing the following issues:
- How will the estimated global sea level rise affect the hydrodynamic of some of the highly populated Portuguese estuarine regions?
- What is the impact of extreme freshwater events on estuarine circulation and on the propagation of the estuarine plume?
- How does plume propagation affects fine sediment distribution and consequently how is primary production distribution in estuaries and near coastal waters affected?
This proposal intends to perform the integrated study of coupled estuarine-near coastal systems in terms of hydro and biogeochemical patterns, with especial emphasis on estuarine plumes dynamics of three of the main Portuguese estuaries (Douro and Tagus estuaries and Ria de Aveiro).
These estuaries are inserted in heavily populated regions and in the vicinity of important commercial and fishing ports (Leixões, Aveiro and Lisbon). Moreover they represent three different types of estuaries: (1) a river dominated estuary (Douro); (2) a costal lagoon (Ria de Aveiro) and (3) a classical shaped estuary (Tagus).