Coastal Risk Module - Class 6 - 04/12/2023

4 Dezembro 2023, 09:00 Maria da Conceição Pombo de Freitas

Coastal Risks Module – Risk associated to the cross-shore dynamics of beaches – retreat and vertical swash reach. Impacts of storms in beach profiles. Seasonal morphologic variability of beach profiles. Coastal dunes. Definition, forcing factors, regional and local. Functions/Services of coastal dunes. The role of vegetation. The dune life cycle.

Praia da Rainha dune beach profiles 1 and 2 performed with DGPS in the field – exercise in Excel - Construction of a cross-sectional topographic profile, identification of the morphosedimentary domains. Comparison with the profiles performed between 2001 and 2019.

Coastal Risk Module - Field Trip Classes 4 and 5 - 27/11/2023

27 Novembro 2023, 11:00 Maria da Conceição Pombo de Freitas

Coastal Risk Module - Field trip on the coast between Cova do Vapor and Fonte da Telha. Models of human occupation, geomorphology and coastal risk on the Costa da Caparica plain. Topographic survey of the beach profile using DGPS in RTK mode. Estimation of the mean diameter and calibration of sediments using a visual comparison chart. Erosion rates on this coastline and coastal protection: groins, sea walls, artificial nourishment, dune recovery (REDUNA project). Projection of the Areas threatened by the sea (erosion and flooding) on this stretch of coast in 2 time periods: 2050 and 2100.

Coastal Risk Module - Class 3 - 20/11/2023

20 Novembro 2023, 09:00 Maria da Conceição Pombo de Freitas

Coastal Risks Module - Cliff retreat and slope mass movements. Rock fall and rockslide, planar and rotational - characteristics, attributes of the rock massifs affected, examples, importance in terms of hazard and risk.

Methods for characterizing the evolution of cliffs: terrestrial LiDAR method; comparison of iconographic documents: photos and maps - advantages and disadvantages. Selection of reference points and a shoreline indicator, identification and marking of the indicator and fixed references on the base document. Procedures for determining average retreat and retreat rates, lost area and volume involved in retreat processes.

Space and coastal risk management on cliff coastlines. Prevention actions, programmed and reactive retreat, intervention. Prevention: setback lines on cliff coasts, launched towards the land side of the crest (cases of resistant or soft massifs), and towards the seaside of the foot: empirical relationships with the height of the cliff. Examples from the national coastline.  Warning signs. Intervention: dismantling of unstable blocks, control solutions based on the containment of erosion materials (rockfall nets, tensioned, dynamic barriers) and stabilization: revetments (shotcrete, revetment with neat block walls, rockfill of the foothills). Examples from the national coastline.

Accumulation coasts - beach-dune systems. Beach: concept; limits, relationship with the coastal domain, functions/services. Composition and size of constituent particles. Morpho-sedimentary domains: submarine and subaerial beach. Morphology of submarine beach – sand bars, ridge and runnel. The subaerial beach: beach face and berms.

The longitudinal dynamics of beaches and the relationship with the oblique approach of waves. Decomposition of incident energy into transverse and longitudinal components. Angular mismatch between the directions of the surge and rebound of oblique waves when they surge and rebound over a beach; consequences: establishment of a drift current and sediment transport (littoral drift). 

The cross-shore dynamics of beaches as a factor in coastal hazard and risk. Profile retreat during storms, vertical reach of the drift. Lowering and emptying of the subaerial beach, barefooting of structures, exposure of building foundations. Overtopping, flooding and the direct impact of breaking waves on elements at risk at the back of the beach.

Flood Risk - Classe 3

13 Novembro 2023, 11:00 Maria do Rosário da Encarnação de Carvalho

Planos de Gestão de risco de inundação: objectivos, metodologia, critérios.

Flood risk management plans: objectives, methodology, criteria.

Coastal Risks Module - class 2 - 13/11/2023

13 Novembro 2023, 09:00 Maria da Conceição Pombo de Freitas

Wave regime on the west coast and the Algarve coast. Wave energy and power. Distribution of wave energy over time. Storms. Storm surge - concept, causes, consequences. Rise in mean sea level (MSL). Causes of MSL variation - tectonics, isostasy and climate. Climatic variations and major climatic events over the last 20,000 years - Last Glacial Maximum, Bolling-Allerod, Younger Dryas, Climatic Optimum, Roman Warm Period, Dark Period, Medieval Warm Period, Little Ice Age. MSL rise curves over the last 20,000 years. Current MSL variation and projection until the end of the 21st century (NOAA, IPCC, MOd.FC).
Rocky coastline - cliffs and abrasion platforms - general concepts. Cliffs - morphological elements, characterization, active processes. Shore platforms - morphological elements, characterization, active processes. Cliff retreat processes. External processes: shear, abrasion, compression - decompression. Intrinsic resistance factors: lithology, fracturing, weathering. The cycle of under-excavation, instabilization, collapse, debris removal. Toe protection and return interval between successive collapses. Cliff retreat and slope mass movements - concept, nomenclature. Types of movement: toppling, rock fall, rockslide, planar and rotational.  Toppling - characteristics, attributes of the rock massifs affected, examples in the Portuguese coast, importance in terms of hazard and risk.