José Simão Antunes do Carmo

Working with Nature by Protecting Sand Dunes: Lessons Learned

Abstract The construction of an underwater effluent damaged the continuity of the Leirosa sand dune system, which is located at south of Figueira da Foz, midway along the Portuguese coast. Considerable damage was caused to the dunes by the use of heavy machinery and by the erosion that occurred afterwards, since the rehabilitation began only 3 y latter. The existence of a breakwater less than 1 km to the north, also served to increase the erosion problems, causing the retention of large amounts of sand. As a consequence, sand accretion had to be the first step in reconstructing the Leirosa dunes. The rehabilitation of this system started in March 2000. After that, and to stabilize the sand, revegetation was carried out with transplants of the grass Ammophila arenaria (L.) Link, the most appropriate plant species used in these situations. The winter of 2000/2001 was particularly severe and in February 2001 most of the oceanic side of the Leirosa rehabilitated sand dune was destroyed during a storm that struck all of central Portugal, especially the coast. Between 2001 and 2009 several proposals for the rehabilitation of the Leirosa sand dunes were studied, including soft and hard engineering interventions. A solution adopted in 2005 consisted of dune reconstruction with layers of geotextiles filled with local sand (geocontainers). Due to problems probably caused by undermining of the bottom layers by local scour, another class of sand-filled containers (geotubes) was installed in early summer 2008 at the bottom of the existing structure as toe protection. Another round of revegetation was planned and implemented in May 2009. A new monitoring program was also implemented to locate, identify, quantify and characterize the existing and planted vegetation. Finally, and again using geotubes as the construction material, a complementary protection for the Leirosa sand dune system is described. It consists of a submerged breakwater (multifunctional artificial reef) that both protects the local coastline and enhances surfing possibilities. The main reef characteristics are presented.

Learning with Nature: A Sand Dune System Case Study (Portugal)

Abstract The implantation of a submarine outfall pipe in 1995 for the cellulose pulp and paper companies Celbi and Soporcel, Portugal, led to some changes in the Leirosa sand dunes system. The use of heavy machinery and the close proximity of a breakwater aggravated the long-term problems of erosion in this coastal ecosystem. Sand accretion was the first step in the reconstruction of the Leirosa dunes. Subsequently, to stabilize the sand, we carried out revegetation, planting the grass Ammophila arenaria (L.) Link. In February 2001, after a particularly severe winter, most of the ocean-facing side of the Leirosa rehabilitated sand dune system was severely damaged. In spite of this problem, the monitoring plan to assess sand erosion and vegetation growth continued. In 2005, after balancing several alternatives, the Leirosa sand dunes were reconstructed with layers of geotextiles filled with sand. Once the sand containers were in place, this protective barrier was covered with sand and planted with A. arenaria, turning this area into an attractive and safe coastal dune system. In March 2006, some problems occurred, probably caused by poor sealing of the geotextiles layers, which led to parts of the three bottom layers breaking open. To stabilize and reinforce the sand dune in this specific weakened area, we are currently analysing the use of geotextile tubes. The attempts to promote the sustainable rehabilitation of a dune system and the implied problems related to its location on a particularly harsh Atlantic coast are discussed in the paper.

Boussinesq and Serre type models with improved linear dispersion characteristics: Applications

The classical Boussinesq equations only incorporate weak dispersion and weak nonlinearity, and are valid only for long waves in shallow waters. The classical Serre equations (or Green and Naghdi) are fully-nonlinear and weakly dispersive. Thus, as for the classical Boussinesq models, Serres equations are valid only for shallow water conditions. To allow applications in a greater range of depth to wavelength ratio, a new set of extended Serre equations with additional terms of dispersive origin is proposed in this work. The equations are solved using an efficient finite-difference method, which consistency and stability are tested by comparison with a closed-form solitary wave solution of these equations. It is shown that computed results agree closely with the analytical ones and test data. An equivalent form of the Boussinesq equations, also with improved linear dispersion characteristics, is solved using a numerical procedure similar to that used to solve the extended Serre equations. Numerical solutions of both approaches, in the case of waves generated by disturbances on the water surface, are compared to each other and with available data, testing different functions commonly used in modelling the generation and propagation of ship waves.The classical Boussinesq equations only incorporate weak dispersion and weak nonlinearity, and are valid only for long waves in shallow waters. The classical Serre equations (or Green and Naghdi) are fully-nonlinear and weakly dispersive. Thus, as for the classical Boussinesq models, Serres equations are valid only for shallow water conditions. To allow applications in a greater range of depth to wavelength ratio, a new set of extended Serre equations with additional terms of dispersive origin is proposed in this work. The equations are solved using an efficient finite-difference method, which consistency and stability are tested by comparison with a closed-form solitary wave solution of these equations. It is shown that computed results agree closely with the analytical ones and test data. An equivalent form of the Boussinesq equations, also with improved linear dispersion characteristics, is solved using a numerical procedure similar to that used to solve the extended Serre equations. Numerical solutio...

Bottom friction and time-dependent shear stress for wave-current interaction

Bottom shear stresses in the wave-current interaction case are calculated using a numerical turbulent-closure model of the K-L type, where K is the turbulent kinetic energy and L is the length scale of the turbulence. Parameterized results of the friction coefficient are obtained in the case of a rough turbulent flow, as presented by Soulsby et al. [14], and these are here extended to the case of a smooth turbulent flow. Several comparisons with experiments and other results presented in the literature, particularly by Tanaka and Thu [19], show close agreement. A new parameterization of the time-series shear stress is proposed that includes a local friction coefficient and yields better results than the parameterization suggested by Soulsby et al. [14].

Wave hydrodynamics around a multi-functional artificial reef at Leirosa

This paper describes an application of the Boussinesq-type COULWAVE model to study the wave hydrodynamics in the vicinity of a multi-functional artificial reef (MFAR). This reef is under investigation and consists of a supplementary protection solution for the Leirosa sand dune system located at South of Figueira da Foz, on the Portuguese West coast. Such installation near the coastline is expected to contribute to enhance the surfing conditions in the area, protect the sand dune system in the surroundings of Leirosa beach, and increase its environmental value. Numerical calculations with the COULWAVE model were performed for four test cases, considering two reef geometries (differing in the reef angle) and two incident wave conditions (storm condition and a common wave condition). Comparisons between the results obtained, in terms of wave heights and breaking line positions allow us to assess the influence of the reef on the hydrodynamics near the beach and around the reef. Moreover, the reef performance was analysed in terms of surfability and coastal protection. The surfability parameters (breaker height, Iribarren number and peel angle) were calculated for each test case using the numerical wave heights, wave directions and wave breaking positions. Comparisons of parameters allow characterizing the most appropriate configuration of the reef to improve the surfing conditions in the study area. A methodology based on numerical free surface elevations and horizontal velocity components was developed to calculate wave directions, since this is not a direct output of the COULWAVE model. Concerning coastal protection, analyses of the mean currents around the reef were used together with observations of the velocity cells near the shoreline as an indication of the sediment transport.

Extended Serre Equations for Applications in Intermediate Water Depths

The Serre or Green and Naghdi equations are fully-nonlinear and weakly dispersive and have a built-in as- sumption of irrotationality. However, like the standard Boussinesq equations, also Serres equations are only valid for long waves in shallow waters. To allow applications in a greater range of h 0 /l, where h 0 and l represent, respectively, depth and wavelength characteristics, a new set of extended Serre equations, with additional terms of dispersive origin, is developed and tested in this work by comparisons with available experimental data. The equations are solved using an ef- ficient finite-difference method, which consistency and stability are analyzed by comparison with a closed-form solitary wave solution of the Serre equations. All cases of waves propagating in intermediate water depths illustrate the good per- formance of the extended Serre equations with additional terms of dispersive origin. It is shown that the computed results are in conformity with the analytical ones and test data. An equivalent form of the Boussinesq type equations, also with improved linear dispersion characteristics, is solved using a numerical procedure similar to that used to solve the extended Serre equations.

Hydrodynamics around an Artificial Surfing Reef at Leirosa, Portugal

As a new alternative countermeasure to protect the coastal zone and to increase the surfing possibilities in the Leirosa area of Portugal, multifunctional artificial reefs were investigated numerically in this paper. The primary surfing parameters used in the design (i.e., breaker type, peel angle, wave height at breaking, and currents around the artificial reef) were analyzed. The reef functionality was also analyzed for coastal protection. Two reef geometries with different reef angles of 45 and 66° were tested, considering two design wave conditions (storm and common) and two tide levels (medium and low). Simulations show that both reef geometries are adequate for surfing, although the reef angle of 66° is more suitable for standard surfers, and the 45° angle is more adequate for advanced/professional surfers. A morphodynamic study should be carried out to analyze the efficiency of the artificial surf reef for coastal protection. DOI: 10.1061/ (ASCE)WW.1943-5460.0000128.

Wave-current interactions over bottom with appreciable variations in both space and time

In shallow water conditions, current and wave propagation cannot be simulated separately and then superposed linearly. In these conditions, in fact, the fluid dynamics of the wave and current motions and, as a consequence, the responses of the movable bed are significantly different from those expected for a linear superposition of a current with a sinusoidal wave. Thus, wave nonlinearity and the wave-current interaction effects become important factors that need to be considered. A model should be also able to reproduce the fluid dynamics under shallow water conditions over significant slopes and time-bed-level changes. This paper presents a 1DH mathematical formulation of a hydrodynamic model and its numerical solution. The model is able to reproduce all characteristic shallow water phenomena, including: (i) wave-wave and wave-current interaction effects; (ii) important ratios between the current and wave velocities; (iii) significant bed slopes and sudden time-bed-level changes, and (iv) friction stresses at the bottom and at the free surface. Different orders of mathematical approximations and appropriate application examples are also presented.

Climate Change, Adaptation Measures, and Integrated Coastal Zone Management: The New Protection Paradigm for the Portuguese Coastal Zone

ABSTRACT Antunes do Carmo, J.S., 2018. Climate change, adaptation measures, and integrated coastal zone management: The new protection paradigm for the Portuguese coastal zone. The efforts made to reduce the causes and mitigate the effects of global climate change continue to be critical in coastal areas. Many adaptation strategies implemented in coastal areas remain inadequate or ineffective. Using primarily events and interventions carried out along the Portuguese Atlantic coast, this work aims to show the paradigm shift that has occurred in Portugal since the last century (the 1990s) within the scope of the National Coastal Zone Management Strategy, taking into account the new guidelines for the implementation of coastal defence works. In this context, this paper also aims to assist coastal communities in carrying out operational coastal management by presenting and discussing management tools and primary options that should be considered in any adaptation programme that is to be implemented. Both nonstructural and structural measures are considered. Action plans, warning systems, emergency plans, and evacuation plans belong to the first category. Education and training are also considered, because they play a key role in the sustainability of coastal areas, especially in the coming generations. Structural measures are adaptation options that are designed to increase the safety of people and reduce risks. They are discussed and grouped into categories that include accommodation, protection, and retreat. Recent cases of successful accommodation and protection measures implemented along the Portuguese coast are also presented and discussed.

Integrated coastal management and adaptation needs

Mangrove waste comprises of naturally decomposed dead mangrove leaves, twigs, and branches. This research aims to determine the types of bacterial symbionts in mangrove waste with potency as anti-bacterial agents. These anti-bacterial agents will subsequently be used in the production of compost with bio-activators. The research process involves isolation of symbiont bacteria, identification for symbiont bacteria with potency as anti-bacterial agent, DNA extraction using High Pure PCR Temperature Preparation Kit (Roche), DNA amplification by PCR 16s rDNA, and DNA Sequencing. Resulting amplified 16S rDNA are analyzed and then sequenced using Genetix program. Symbionts with identified anti-bacterial properties are used in bio-activator production. Samples of Sargassum seaweed are treated separately with resulting bio-activator product from the research and other bio-activator products for nutritional content comparison. Four types of symbiont bacteria are identified as potential anti-bacterial agents, namely Pseudomonas sp., Flavobacterium sp., Acinetobacter sp., Bacillus subtilis. It is further found that bio-activator products from mangrove waste have better quality compared to those found in the market and non-bio activator added liquid organic fertilizers. Therefore, bio-activators from mangrove waste is a potential alternative as natural bio-activator productsT coastal ocean connects terrestrial (e.g., rivers and estuaries) with oceanic ecosystems and is considered as a major component of global carbon cycles and budgets. The coastal waters are featured with a high biodiversity and high primary production. Because of the excessive primary production, a large fraction of primary organic matter becomes available to consumers as detritus in the coastal waters. Bacterioplankton have long been known to play a key role in the degradation of this detritus, and export and storage of organic matter in the coastal ecosystems. However, the primary and secondary production and the carbon biogeochemical processes in the ecosystems are largely regulated by nutrient inputs from riverine and other anthropogenic activities through heterotrophic microbial communities.A major gap exists in integrating climate projections and social–ecological vulnerability analyses at scales that matter, which has affected local-scale adaptation planning and actions to date. We address this gap by providing a novel methodology that integrates information on: (i) the expected future climate, including climate-related extreme events, at the village level; (ii) an ecological assessment of the impacts of these climate forecasts on coral reefs; and (iii) the social adaptive capacity of the artisanal fishers, to create an integrated vulnerability assessment on coastal communities in five villages in Papua New Guinea. We show that, despite relatively proximate geographies, there are substantial differences in both the predicted extreme rainfall and temperature events and the social adaptive capacity among the five fishingdependent communities, meaning that they have likely different vulnerabilities to future climate change. Our methodology shows that it is possible to capture social information and integrate this with climate and ecological modeling in ways that are best suited to address the impacts of climate-mediated environmental changes currently underway across different scales.T coastal zone (CZ) is a social-ecological system (SES) that is both dynamic and complex. Coastal SES are some of the most valuable in the Earth System (ES). The high ecologic, social and economic value of the coastal zone is influenced by global and climate changes, as well as pressures from anthropogenic activities. The rapid development of the economy and society in China has led to a concentration of the human population along the coast. This puts these coastal SES under increasing and multiple pressures, but also increases the risk to the population from dramatic accidents (e.g. oil spills, Tianjin explosion) and natural hazards (e.g. storm surges). Such accidents have resulted in the deterioration of the coastal environment, damage to natural resources, and loss of ecosystem functions and services. A comprehensive understanding of the coastal natural status, changes and resilience is fundamental for sustainable development. Such knowledge is the basis for the adaptive management of coastal SES and is crucial to their sustainability. Several analytical frameworks exist to support the adaptive management of the coastal SES. They can contribute valuable insights and be used together to develop a locally adapted integrative framework. Research on coastal environmental damage assessment (CEDA) as well as coastal social-ecological systems in China aims to setup a technical framework for CEDA and to contribute to co-designed, locally-adapted integrative management frameworks. This paper presents our preliminary results to provide scientific support for the policymaking with respect to the sustainable coastal zone management in China.