André PachecoUniversidade do Algarve | UALG · Centro de Investigação Marinha e Ambiental (CIMA)
André Pacheco
PhD Physical Oceanography
About
66
Publications
22,815
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1,045
Citations
Citations since 2017
Introduction
More details, please view my personnal webpage at: http://w3.ualg.pt/~ampacheco/
Topics of current research on HIGHLIGHTS
Additional affiliations
April 2012 - present
Position
- PostDoc Position
Description
- Examine aspects related to the potential installation of Tidal Stream Turbines (TSTs) on a confined tidal inlet channel, in particular.
October 2011 - March 2012
Position
- PostDoc Position
Description
- Field data collection of overwash events over breakwaters to set-up, calibrate and validate a Smoothed Particle Hydrodynamic modeldeveloped by the project leader Dr. Eric Didier from the Portuguese National Laboratory of Civil Engineering (LNEC)
January 2011 - September 2011
Position
- PostDoc Position
Description
- Data processing, development of Early Warning Systems to prevent impact of extreme storm events and scientific spreading actions.
Education
December 2006 - January 2010
September 1996 - September 2002
Publications
Publications (66)
The development on tidal turbine technology is ongoing with focus on several aspects, including hydrodynamics, operation and environment. Before considering an area for exploitation, tidal energy resource assessments in pre-feasibility energy extraction areas must include the relevant characteristics of the device to be used. The present paper uses...
Although it is generally acknowledged that most multiple inlets are unstable and cannot coexist, there is evidence to suggest that such inlets can indeed be stable over decadal time scales. Multiple-inlet systems servicing a single embayment, in contrast to single-inlet systems, confer particular hydrodynamic characteristics such as the potential e...
Sea level rise will be a major threat to coastal communities within the next century due to the intensity and severity of the floods it can cause. A new methodology considering water infiltration, slope, and hydraulic connectivity was developed to assess the potential inundation extension associated with different total water level and sea level ri...
RESUMO A implementação de estratégias de circularidade pode ser um importante contributo para a melhoria da eficiência da gestão dos recursos naturais, nomeadamente da água e da energia, sobretudo nas zonas urbanas onde vive a maioria da população mundial. No domínio do ciclo urbano da água, essa eficiência é fundamental, sobretudo no atual cenário...
Islands have the potential to be precursors in the transition to clean energy, by adopting new technologies and applying innovative solutions that can serve as showcases at an international level. This paper is a contribution towards understating the importance of community engagement on energy transition processes. It covers multiple aspects of a...
In this paper the turbulence effects are studied for three rotors mounted on the same instrumented hub. Two scaled models of industrial turbines and one open-geometry turbine are considered. The turbulence characteristics are obtained from 2D Laser Doppler Velocimeter measurements and the turbine behaviour is analysed from thrust and torque measure...
The energy that can be extracted from tidal currents is one of the most promising renewable energy sources due to its high density/predictability. Within this paper this energy source is evaluated economically respecting sustainability principles. This evaluation contrasts from previous studies due to the application of a cost-benefit analysis base...
The Ria Formosa is a sheltered large coastal lagoon located on the Atlantic South Coast of Portugal, that has been classified as a natural park since 1987. The lagoon hosts a diverse and abundant fish community and other species of commercial importance. Several economical activities are supported by shipping, and as such, vessel traffic within the...
This paper presents the results of a pilot experiment with an existing tidal energy converter (TEC), Evopod 1 kW floatable prototype, in a real test case scenario (Faro Channel, Ria Formosa, Portugal). A baseline marine geophysical, hydrodynamic and ecological study based on the experience collected on the test site is presented. The collected data...
Overwash hydrodynamic datasets are mixed in quality and scope, being difficult to obtain due to fieldwork experimental limitations. Nevertheless, these measurements are crucial to develop reliable models to predict overwash. Aiming to overcome such limitations, this work presents accurate fieldwork data on overwash hydrodynamics, further exploring...
This paper presents a study for estimating the size of a tidal turbine array for the Faro-Olhão Inlet (Potugal) using a surrogate optimization approach. The method compromises problem formulation, hydro-morphodynamic modelling, surrogate construction and validation, and constraint optimization. A total of 26 surrogates were built using linear RBFs...
A B S T R A C T - This paper investigates the optimum tidal energy converter array density at a tidal inlet by applying surrogate-based optimisation. The SBO procedure comprises problem formulation, design of experiments, numerical simulations , surrogate model construction and constrained optimisation. This study presents an example for the Faro-O...
This paper presents the results of a pilot experiment with an existing tidal energy converter (TEC), Evopod 1 kW floatable prototype, in a real test case scenario (Faro Channel, Ria Formosa, Portugal). Operational results related to the description of power generation capacity, energy capture area and proportion of energy flux are presented and dis...
This presentation presents the results of a pilot experiment with an existing tidal energy converter (TEC), Evopod 1 kW floatable prototype, in a real test case scenario (Faro Channel, Ria Formosa, Portugal). Operational results related to the description of power generation capacity, energy capture area and proportion of energy flux are presented...
This paper presents the results of a pilot experiment with an existing tidal energy converter (TEC), Evopod 1 kW floatable prototype, in a real test case scenario (Faro Channel, Ria Formosa, Portugal). A baseline marine geophysical, hydrodynamic and ecological study based on the experience collected on the test site is presented. The collected data...
This paper investigates the effects of Tidal Energy Converter (TEC) array size at a tidal channel on flood/ebb discharges at multi-inlet coastal lagoon by applying numerical modelling. The paper presents a case study for the Faro-Olhão inlet in the Ria Formosa (Portugal), a potential site for tidal in-stream energy extraction. Arrays of up to 11 ro...
This paper investigates the effects of Tidal Energy Converter (TEC) array size at a tidal channel on flood/ebb discharges at multi-inlet coastal lagoon by applying numerical modelling. The paper presents a case study for the Faro-Olhão inlet in the Ria Formosa (Portugal), a potential site for tidal instream energy extraction. Arrays of up to 11 row...
Overwash hydrodynamics datasets are mixed in quality and scope, being hard to obtain due to fieldwork experimental difficulties. Aiming to overcome such limitations, this work presents accurate fieldwork data on overwash hydrodynamics, further exploring it to model overwash on a low-lying barrier island. Fieldwork was performed on Barreta Island (P...
Overwash hydrodynamics were measured during a storm event. Data from literature and fieldwork were used to setup a numerical model, using XBeach in non-hydrostatic mode. Different simulations were conducted to assess the influence of several factors on overwash statistics. Nearshore morphology was found to greatly influence overwash. Sediment mean...
The challenge for floating offshore wind structures is to reduce costs. The industry needs a wind turbine support solution that can be fabricated and deployed from existing shipyards and port facilities, while investors need accurate estimations and forecasts of wind resources and quantified information on the inherent variability in wind power gen...
The challenge for floating offshore wind structures is to reduce costs. The industry needs a wind turbine support solution that can be fabricated and deployed from existing shipyards and port facilities, while investors need accurate estimations and forecasts of wind resources and quantified information on the inherent variability in wind power gen...
The east coast of the Algarve (Olhos de Água –
Guadiana) is a low sandy coast with a high diversity of environments,
including a cliffed coast, sandy beaches, dune
ridges, an estuary, artificial/antrophic sectors and a main, complex,
central morphology: the Ria Formosa barrier islands and
coastal lagoon system. The large majority of this coastal se...
The seasonal and annual nitrogen (N), phosphorus (P), and carbon (C) budgets of the mesotidal Ria Formosa lagoon, southern Portugal, were estimated to reveal the main inputs and outputs, the seasonal patterns, and how they may influence the ecological functioning of the system. The effects of extreme weather events such as long-lasting strong winds...
The east coast of the Algarve (Olhos de Água –
Guadiana) is a low sandy coast with a high diversity of environments,
including a cliffed coast, sandy beaches, dune
ridges, an estuary, artificial/antrophic sectors and a main, complex,
central morphology: the Ria Formosa barrier islands and
coastal lagoon system. The large majority of this coastal se...
Ancão Inlet is a small migrating inlet that was relocated in 1997 and has been monitored since then. In October 2015, it was about to conclude its third eastward migrating cycle since the 1940s. Morphological parameters and migration rates were correlated with oceanographic settings to evaluate the importance of different mechanisms in the evolutio...
This work intends to determine if low-cost surveying techniques based on recreational echosounders can be used to perform nearshore bathymetry for analysing evolution of coastal sectors. For that purpose two hydrographic surveying techniques were compared, i.e. (1) a RTK-DGPS synchronised with a single beam echo sounder with real time tidal elevati...
The CURTTOOLBOXv1.0 is a collection of scripts for computing hydrodynamic parameters and total (bedload+suspended) sediment transport derived from Acoustic Doppler Profilers (ADP's). The m-files were written for a 1500kHz ADP operating on bottom tracking (SonTek/YSI, Inc).
Research into the consequences of engineering works on the long-term behaviour of inlet systems has been hindered by the absence of suitable datasets, the shortcomings of existing formulae and evaluation tools. Cross-sectional channel areas adjust to hydrodynamics and sediment transport conditions. The impacts of a new inlet on the adjacent shoreli...
This paper presents a statistical evaluation of two theoretical fitting methods — logarithmic and power law — commonly used to extrapolate velocities to unmeasured areas of a vertical profile, such as near-bottom velocities. Analysis of covariance (ANCOVA) was used to test the models' performance when applied to velocity data collected with a boat-...
The study aims to calibrate/validate and apply the dune-erosion model, XBeach, in order to predict morphological response to storm events along a meso-tidal, steeply sloping beach. More than 10,000 XBeach calibration runs, including different model parameters and erosion events, were compared with measurements of beach-profile response to storm con...
Very few studies have quantified the wave friction factor, f w , for coarse sediments at field-scale. To address this shortcoming, high-frequency measurements of turbulence obtained within the boundary layer of irreg-ular waves over gravel in the Delta Flume, have been used to calculate values of f w using different evaluation methods. In the field...
The present contribution presents efforts towards the development of an
operational Early Warning System for storm hazard prediction and
mitigation. The system consists of a calibrated nested-model train which
consists of specially calibrated Wave Watch III, SWAN and XBeach models.
The numerical simulations provide daily forecasts of the hydrodynam...
Tidal currents offer considerable potential for the generation of renewable energy. A study to assess the potential of a site for tidal energy extraction needs to be effective on providing information on the precise distribution of the tidal stream energy (Carballo et al., 2009) as well as detailed assessment of the sites potentially viable for ins...
This article defines short-term (tidal cycle) sediment-transport patterns at a backbarrier beach based on detailed field studies. Fieldwork was planned to record nonstorm, spring tide conditions that enable the definition of background sediment dynamics at the study area. The experiment was set at two beach morphologies: beach face and sandbank. Cu...
In this study, the artificial opening of a new tidal inlet in an existing multiple inlet system is shown to significantly modify the adjacent nearshore and backbarrier morphology, as well as both updrift and downdrift shorelines. The study focuses on the dominant Faro-Olhão and Armona inlets in the Ria Formosa barrier island system of southern Port...
A sandy beach in the south of Portugal (Faro beach, Ria Formosa) was surveyed from the dune crest seaward to 15 m depth 20 times over a period of 26 months. Wave time-series between surveys were analysed to obtain relationships between wave height and vertical profile variations and to define wave thresholds for important morphological changes. Res...
Research into the consequences of engineering works on the long-term behaviour of inlet systems has been hindered by the absence of suitable datasets, the shortcomings of existing formulae when applied to different inlets, and the difficulties particular to multi-inlet situations. Cross-sectional channel areas adjust to hydrodynamics and sediment t...
Bezerra, M., Ferreira, O., Pacheco, A., Freitas, M. C., Pires, R., Andrade, C. and Taborda, R., 2011. Evolution stages of an ephemeral inlet immediately after artificial opening. Journal of Coastal Research, SI 64 (Proceedings of the 11th International Coastal Symposium), 1453 - 1456. Szczecin, Poland, ISSN 0749-0208 The study of inlet morphology i...
The morphodynamic evolution of the barrier/inlet of Santo André and relationships between tidal prism and morphological parameters of the inlet were analyzed through seventeen topo-bathymetric surveys. Following the artificial opening of the inlet (March 9, 2009) a prolonged ebb occurred, currents peaking at 6 m/s and excavating a linear V-shaped c...
The complex interaction between morphogenetic processes acting on rocky
coasts and substrate characteristics difficult the assessment of its
evolution at different time scales. In opposition to other coastal
environments such as beaches, where variations on substrate's attributes
are constrained to a few possibilities, rocky coasts expose substrate...
The complex interaction between morphogenetic processes acting on rocky coasts and substrate characteristics difficult the assessment of its evolution at different time scales. In opposition to other coastal environments such as beaches, where variations on substrate's attributes are constrained to a few possibilities, rocky coasts expose substrate...
The present study documents the poorly-described hydro-sediment dynamics of narrow bedrock-controlled estuaries during periods of low-river discharge. The results also contribute to assess the geomorphological evolution of these systems, when affected by drastic flow regulation. The Guadiana Estuary is a narrow rock-bound mesotidal estuary, 80 km i...
This paper compares several methodologies used to compute skin-friction shear stresses and drag coefficients using different methods and equipments: a set of pressure transducers, an acoustic Doppler velocimeter (ADV) and an acoustic Doppler profiler (ADP). The study area is the Ancão Inlet (Ria Formosa, Southern Portugal), an inlet with a mixed wa...
The study focuses on the western end of the Ria Formosa in Portugal. This evolving sedimentary system comprises barrier islands and three contrasting and connected inlets: Ancão (relocated in 1997 and ebb tide-dominated), Faro-Olhão (opened and stabilised between 1927 and 1958, flood tide-dominated) and Armona (natural and ebb tide-dominated). The...
Research into the response of coastlines to the opening and stabilisation of inlets has been limited by the availability of suitable data, the shortcomings of existing formulae when applied to different inlets, and the difficulties particular to multi-inlet situations. Our appraisal of methodologies for studying inlet dynamics leads us to formulate...
Management of the interactions between social/economic interests and the coastal environment requires practical, interdisciplinary assessment techniques. Backbarrier systems are critical natural resources that provide both economic and social benefits. Activities such as aquaculture, fishing, shipping and port activities, sediment mining, salt extr...
Ancão Inlet (Southern Portugal) was relocated in 1997 and almost 10 years after its opening has the morphodynamic characteristics and migration pattern predicted by several authors. Its eastwards migration is
mostly caused by high W-SW storm events, where the downdrift migration of the channel is accompanied by updrift spit growth and both deltas m...
Uncontrolled dredging in complex environments such as barrier island systems can produce major changes in inlet conditions, current circulations patterns and modify channel margins, leading to silting or erosion. This paper presents a study of the evolution of Faro Channel between 1927 and 2001, in the Ria Formosa barrier island system, taking into...
Determination of inlet hazard areas (IHAs) is important for the management of barrier island systems such as the Ria Formosa. An IHA is an area of natural importance that can be easily destroyed by inlet-related processes and covers the land adjacent to inlets [CAMA, 2004. Handbook for Development in Coastal North Carolina. Division of Coastal Mana...
Inlet opening greatly modify the nearshore and bay morphology, as well as both updrift and downdrift shorelines. This paper analyses the evolution of the downdrift coast as response to the opening and stabilisation of an inlet at south Portugal. The inlet opening and stabilisation was responsible by two major effects on the downdrift coast: (1) dra...
Questions
Question (1)
Looking for MatLab scripts on inversion algorithms of Landsat8 images to bathymetric maps using known depths and water quality parameters (based on know bibliography i.e Stumpf & Holderied 2003; Albert & Mobley, 2003). Also, suggestions on possible problems on applying the technique (e.g. atmospheric corrections, calibration curves, amongst others). Thanks
