34 results on '"Payo, Andres"'
Search Results
2. Responding to climate change around England's coast - The scale of the transformational challenge
- Author
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Sayers, Paul, Moss, Charlotte, Carr, Sam, and Payo, Andres
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- 2022
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3. Multispectral satellite imagery and machine learning for the extraction of shoreline indicators
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McAllister, Emma, Payo, Andres, Novellino, Alessandro, Dolphin, Tony, and Medina-Lopez, Encarni
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- 2022
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4. Application of portable streamer traps for obtaining point measurements of total longshore sediment transport rates in mixed sand and gravel beaches
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Payo, Andres, Wallis, Humphrey, Ellis, Michael A., Barkwith, Andrew, and Poate, Timothy
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- 2020
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5. Sediment Thickness Model of Andalusia's Nearshore and Coastal Inland Topography.
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Torrecillas, Cristina, Payo, Andres, Cobos, Manuel, Burke, Helen, Morgan, Dave, Smith, Helen, and Jenkins, Gareth Owen
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GEOLOGICAL maps ,COASTAL zone management ,SEDIMENTS ,TOPOGRAPHY ,COASTAL sediments ,COASTS ,GEOLOGICAL mapping - Abstract
This study represents the first attempt to map the sediment thickness spatial distribution along the Andalusian coastal zone by integrating various publicly available datasets. While prior studies have presented bedform- and sediment-type syntheses, none have attempted to quantify sediment thickness at the scale and resolution performed in this study. The study area has been divided into 18 physiographic zones, and we have used BGS Groundhog Desktop v2.6 software for 3D modeling and sediment thickness model calculations. We present here the modeling workflow, model results, and the challenges that we have encountered, including discrepancies in geological maps, difficulty managing data input for grain size/consolidation, and the need for additional geological information. We have compared the modeled sediment fractions of the unconsolidated material with 4194 seabed samples distributed along the study area and found that the differences between the modeled versus the sampled emphasized the importance of incorporating river contributions, particularly from the Guadalquivir River, into the model for more accurate results. The model intermediate and final outputs and the software routines used to query the sediment thickness model are provided as publicly accessible datasets and tools. The modeled sediment thickness could contribute to making quantitative predictions of morphological change at a scale that is relevant to longer-term strategic coastal management in Andalusia. The methodology and tools used for this study are transferable to any study area. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Assessment of Shoreline Change from SAR Satellite Imagery in Three Tidally Controlled Coastal Environments.
- Author
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Savastano, Salvatore, Gomes da Silva, Paula, Sánchez, Jara Martínez, Tort, Arnau Garcia, Payo, Andres, Pattle, Mark E., Garcia-Mondéjar, Albert, Castillo, Yeray, and Monteys, Xavier
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SAND dunes ,SHORELINES ,REMOTE-sensing images ,SYNTHETIC aperture radar ,REMOTE sensing ,RAINFALL - Abstract
Coasts are continually changing and remote sensing from satellites has the potential to both map and monitor coastal change at multiple scales. Unlike optical technology, synthetic aperture radar (SAR) is uninfluenced by darkness, clouds, and rain, potentially offering a higher revision period to map shoreline position and change, but this can only be feasible if we have a better interpretation of what shorelines as extracted from SAR imagery represent on the ground. This study aims to assess the application of shorelines extracted from SAR from publicly available satellite imagery to map and capture intra-annual to inter-annual shoreline variability. This is assessed in three tidally controlled coastal study areas that represent sand and gravel beaches with different backshore environments: low-lying dunes and marsh; steep, rocky cliff; and urban environments. We have found that SAR shorelines consistently corresponded to positions above the high-water mark across all three sites. We further discuss the influence of the scene geometry, meteorological and oceanographic conditions, and backshore environment and provide a conceptual interpretation of SAR-derived shorelines. In a low-lying coastal setting, the annual change rate derived through SAR presents a high degree of alignment with the known reference values. The present study contributes to our understanding of the poorly known aspect of using shorelines derived from publicly available SAR satellite missions. It outlines a quantitative approach to automatically assess their quality with a new automatic detection method that is transferable to shoreline evolution assessments worldwide. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Innovative Representation of the Coastal Topo-Bathymetry and Subsurface for Flooding and Erosion Risk Reduction.
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Payo, Andres
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FLOOD risk ,SHORELINES ,COASTS ,COASTAL changes ,CLIFFS ,COASTAL zone management ,CONE penetration tests ,TRANSECT method - Abstract
In this study, the authors verified the results by comparing them to those of other survey techniques, such as ground-penetrating RADAR, the multi-channel analysis of surface waves (MASW), and cone penetration tests. This was assessed at three macro-tidal study sites along the coastline of England, UK: estuarine, soft cliff environment, and gravel pocket beach. Morgan et al. (2022) [[1]] explored the use of a new survey method, the Passive Seismic Survey (PSS), to assess the beach sediment thickness in different coastal environments on the coast of England, UK. [Extracted from the article]
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- 2023
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8. Simulating mesoscale coastal evolution for decadal coastal management: A new framework integrating multiple, complementary modelling approaches
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van Maanen, Barend, Nicholls, Robert J., French, Jon R., Barkwith, Andrew, Bonaldo, Davide, Burningham, Helene, Brad Murray, A., Payo, Andres, Sutherland, James, Thornhill, Gillian, Townend, Ian H., van der Wegen, Mick, and Walkden, Mike J.A.
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- 2016
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9. Appropriate complexity for the prediction of coastal and estuarine geomorphic behaviour at decadal to centennial scales
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French, Jon, Payo, Andres, Murray, Brad, Orford, Julian, Eliot, Matt, and Cowell, Peter
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- 2016
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10. Causal Loop Analysis of coastal geomorphological systems
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Payo, Andres, Hall, Jim W., French, Jon, Sutherland, James, van Maanen, Barend, Nicholls, Robert J., and Reeve, Dominic E.
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- 2016
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11. Feedback structure of cliff and shore platform morphodynamics
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Payo, Andres, Hall, Jim W., Dickson, Mark E., and Walkden, Mike J. A.
- Published
- 2015
12. Projected changes in area of the Sundarban mangrove forest in Bangladesh due to SLR by 2100
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Payo, Andres, Mukhopadhyay, Anirban, Hazra, Sugata, Ghosh, Tuhin, Ghosh, Subhajit, Brown, Sally, Nicholls, Robert J., Bricheno, Lucy, Wolf, Judith, Kay, Susan, Lázár, Attila N., and Haque, Anisul
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- 2016
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13. Suspended sand transport along pier depression
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Payo, Andres, Kobayashi, Nobuhisa, and Yamada, Fumihiko
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Coastal engineering -- Research ,Sediment transport -- Measurement ,Sediment, Suspended -- Properties ,Engineering and manufacturing industries ,Science and technology - Abstract
Velocities and sand concentrations measured along 20 transects at the Field Research Facility (FRF) at Duck, North Carolina during October 16-23, 1997 are analyzed to examine the cross-shore and longshore suspended sand transport in the FRF pier depression. The suspended sand volume [V.sub.s] per unit bottom area remains large outside the surf zone in the depression. The depth-integrated offshore and longshore suspended sand transport rates are shown to be estimated as a, [bar.U] [V.sub.s] and [bar.V] [V.sub.s], respectively, where the empirical parameter a is in the range of 0.1-0.4 in the depression, [bar.U] is the cross-shore current and [bar.V] is the longshore current. The offshore suspended sand transport rate at the end of the pier is estimated to be as large as 3.5 [m.sup.3]/h/m at the peak of a storm with an offshore significant wave height of 3.5 m. The sand transported offshore appears to have been supplied by the longshore sand transport toward the pier depression. CE Database subject headings: Littoral currents; Waves; Sand; Suspended sediment; Sediment transport; Beaches; Piers.
- Published
- 2009
14. Berm and dune erosion during a storm
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Kobayashi, Nobuhisa, Buck, Mitchell, Payo, Andres, and Johnson, Bradley D.
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Sand dunes -- Properties ,Soil erosion -- Observations ,Storm damage -- Evaluation ,Coastal engineering -- Research ,Sediment transport -- Observations ,Engineering and manufacturing industries ,Science and technology - Abstract
The prediction of berm and dune erosion during a storm is essential for storm damage assessment. Simple and transparent formulas for the cross-shore and longshore transport rates of suspended sediment and bed load on beaches are proposed and incorporated into a combined wave and current model to predict the berm and dune erosion under normally and obliquely incident irregular waves. Two small-scale experiments for two different berm profiles were conducted for the calibration of the developed numerical model. The calibrated numerical model is shown to predict the measured berm and dune erosion in these experiments as well as dune erosion measured in three large-scale tests with errors less than a factor of two. The numerical model is used to examine the effects of the wave period and incident wave angle on the berm and dune erosion. These effects are computed to be within a factor of two. DOI: 10.1061/(ASCE)0733-950X(2009)135:1(1) CE Database subject headings: Berms; Dunes; Sand; Erosion; Beaches; Sediment transport; Bed loads; Storms; Surf zone.
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- 2009
15. Passive Seismic Surveys for Beach Thickness Evaluation at Different England (UK) Sites.
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Morgan, David, Gunn, David, Payo, Andres, and Raines, Michael
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SEISMIC surveys ,BEACHES ,CONE penetration tests ,GROUND penetrating radar ,BEDROCK ,GEOMORPHOLOGY - Abstract
In an era of environmental change leading to rising sea levels and increased storminess, there is a need to quantify the volume of beach sediment on the coast of Britain in order to assess the vulnerability to erosion using cheap, easy-to-deploy and non-invasive methods. Horizontal-to-vertical spectral ratio (HVSR) is a technique that uses the natural background seismic 'noise' in order to determine the depth of underlying geological interfaces that have contrasting physical properties. In this study, the HVSR technique was deployed at a number of settings on the coast of England that represented a range of different compositions, geomorphology, and underlying bedrock. We verified the results by comparison to other survey techniques, such as ground-penetrating RADAR, multichannel analysis of surface waves (MASW), and cone penetration tests. At locations where there was sufficient contrast in physical properties of the beach material compared to the underlying bedrock, the beach thickness (and therefore the volume of erodible material) was successfully determined, showing that HVSR is a useful tool to use in these settings. [ABSTRACT FROM AUTHOR]
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- 2022
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16. Evidence of Former Sea Levels from a Passive Seismic Survey at a Sandy Beach; Perranporth, SW England, UK.
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Payo, Andres, Jenkins, Gareth O., Morgan, Dave, Valiente, Nieves G., and Scott, Timothy
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SEISMIC surveys ,GLACIAL isostasy ,GEOPHYSICAL observations ,BEDROCK ,SEDIMENTARY rocks ,SEA level ,BEACHES - Abstract
Since the end of the last glaciation, the United Kingdom's land surface has been altered by isostatic rebound, rising in the north and sinking in the south. Numerous studies have been published documenting the impact of isostatic rebound on relative sea levels. However, due to the difficulties in acquiring evidence to prove former sea levels, locally, these data can be sparse or absent. In this work, we explored the suitability of the passive seismic survey (PSS) method to estimate the contemporaneous beach thickness in coastal environments where there is a high impedance contrast between the beach deposits and the underlying wave-cut platform. We conducted a three-day survey at Perran Beach, Cornwall, collected 149 measurements using PSS, and interpreted the observations supported by auxiliary topographical, geological, and independent geophysical observation in the study area. The study site is a contemporaneous beach mostly composed of sand underlain by a wave-cut platform composed of igneous and sedimentary rock, therefore high impedance contrast with the sandy beach is anticipated. The elevation of the bedrock relative to the topographical elevation suggests that the bedrock elevation is −15 m ± 5 m below the present day mean sea level, which is coherent with the observation of relative sea level rise along the region of the south-west. The present study contributes to our current limited understanding of land and sea level movements by providing further subsurface information to the coastal geological archive of south-west England, a region currently in need of more data to reconstruct land- and sea-level movements. [ABSTRACT FROM AUTHOR]
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- 2022
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17. Geomorphic State Indicators for coastal management over decades and longer time scales
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Payo, Andres, Hall, Jim W, French, Jon R, Sutherland, James, and Nicholls, Robert J
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- 2018
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18. Modelling daily soil salinity dynamics in response to agricultural and environmental changes in coastal Bangladesh
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Payo, Andres, Lázár, Attila N., Clarke, Derek, Nicholls, Robert J., Bricheno, Lucy, Mashfiqus, Salehin, and Haque, Anisul
- Subjects
food and beverages - Abstract
Understanding the dynamics of salt movement in the soil is a prerequisite for devising 23 appropriate management strategies for land productivity of coastal regions, especially low lying 24 delta regions which support many millions of farmers around the world. In this research, we 25 develop a novel holistic approach to simulate soil salinization comprising an emulator-based soil 26 salt and water balance calculated at daily time steps. The method is demonstrated for the 27 agriculture areas of Coastal Bangladesh. This shows that we can reproduce the dynamics of soil 28 salinity under multiple land uses, including rice crops, combined shrimp and rice farming, as 29 well as non-rice crops. The model also reproduced well the observed spatial soil salinity for the 30 year 2009. Using this approach, we have projected the soil salinity for three different climate 31 ensembles, including relative sea-level rise for the period 2041-2050. The results indicate an 32 increase in soil salinity in 21-44% of the simulated area. This can potentially cause significant 33 crop yield reductions, especially for vegetables and local rice varieties. The modelling approach 34 will enable planners and land use managers to investigate future trajectories of salinity impacts 35 on crop production, considering expected changes in relative sea level, groundwater pumping 36 and water quality in the rivers and estuary, and management responses to augment freshwater 37 supplies.
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- 2017
19. The hydro-environment and livelihoods in coastal Bangladesh
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Lazar, Attila, Nicholls, Robert J, Hutton, Craig, Adams, Helen, Payo, Andres, Salehin, Mashfiqus, Haque, Anisul, Clarke, Derek, Bricheno, Lucy, Fernandes, J.A., Barbour, Emily, Allan, Andrew, Begum, Dilruba, and Szabo, Sylvia
- Abstract
Deltas represent one of the most densely populated areas in the world. This is especially true for the coastal zone of Bangladesh where more than a thousand people live in each square kilometre of land. Livelihoods, food security and poverty in Bangladesh are strongly dependent on natural resources affected by several factors including climate variability and change, upstream river flow modifications, commercial fish catches in the Bay of Bengal, and engineering interventions such as polderisation. The scarcity of fresh water, saline water intrusion and natural disasters (e.g. river flooding, cyclones and storm surges) have negative impact on drinking water availability and crop irrigation potential; thus severely affect land use and livelihood opportunities of the coastal population. Hydro-environmental changes can be especially detrimental for the well-being of the poorest households that are highly dependent on natural resources. The ESPA Deltas project aims to holistically examine the interaction between the coupled bio-physical environment and the livelihoods of these poor populations in coastal Bangladesh. Here we describe a new integrated model that allows the long-term analysis of the possible changes in this system by linking projected changes in physical processes (e.g. river flows, nutrients), with productivity (e.g. fish, rice), social processes (e.g. access, property rights, migration) and governance/management (e.g. fisheries, agriculture, water and land use management). This integrated approach is designed to provide Bangladeshi policy makers with science-based evidence of possible development trajectories within the coastal delta plain over timescales up to 50 years, including the likely robustness of different governance options on natural resource conservation and poverty levels. This presentation describes the model framework and aims to illustrate the cause-effect relationship in-between changes of the hydro-environment and the livelihoods of the coastal population of Bangladesh. Thus, it adds the human dimension to a civil engineering modelling approach
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- 2015
20. Development of an automatic delineation of cliff top and toe on very irregular planform coastlines (CliffMetrics v1.0).
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Payo, Andres, Jigena Antelo, Bismarck, Hurst, Martin, Palaseanu-Lovejoy, Monica, Williams, Chris, Jenkins, Gareth, Lee, Kathryn, Favis-Mortlock, David, Barkwith, Andrew, and Ellis, Michael A.
- Subjects
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SHORELINES , *DIGITAL elevation models , *ENVIRONMENTAL sciences , *ATMOSPHERIC models , *COMPUTER algorithms - Abstract
We describe a new algorithm that automatically delineates the cliff top and toe of a cliffed coastline from a digital elevation model (DEM). The algorithm builds upon existing methods but is specifically designed to resolve very irregular planform coastlines with many bays and capes, such as parts of the coastline of Great Britain. The algorithm automatically and sequentially delineates and smooths shoreline vectors, generates orthogonal transects and elevation profiles with a minimum spacing equal to the DEM resolution, and extracts the position and elevation of the cliff top and toe. Outputs include the non-smoothed raster and smoothed vector coastlines, normals to the coastline (as vector shape files), xyz profiles (as comma-separated-value, CSV, files), and the cliff top and toe (as point shape files). The algorithm also automatically assesses the quality of the profile and omits lowquality profiles (i.e. extraction of cliff top and toe is not possible). The performance of the proposed algorithm is compared with an existing method, which was not specifically designed for very irregular coastlines, and to manually digitized boundaries by numerous professionals. Also, we assess the reproducibility of the results using different DEM resolutions (5, 10 and 50 m), different user-defined parameter sets related to the degree of coastline smoothing, and the threshold used to identify the cliff top and toe. The model output sensitivity is found to be smaller than the manually digitized uncertainty. The code and a manual are publicly available on a GitHub repository. [ABSTRACT FROM AUTHOR]
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- 2018
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21. MODELING THE RESPONSE OF COUPLED BARRIER AND CLIFF SYSTEMS TO SEA LEVEL RISE.
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WALKDEN, MIKE, PAYO, ANDRES, BARNES, JOHN, and BURNINGHAM, HELENE
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SEA level ,COASTAL zone management ,TOPOGRAPHY ,CLIFFS ,BEACHES - Published
- 2015
22. IMPROVING DECADAL COASTAL GEOMORPHIC PREDICTIONS: AN OVERVIEW OF THE iCOASST PROJECT.
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NICHOLLS, ROBERT J., FRENCH, JON, BURNINGHAM, HELENE, VAN MAANEN, BAREND, PAYO, ANDRES, SUTHERLAND, JAMES, WALKDEN, MIKE, THORNHILL, GILL, BROWN, JENNY, LUXFORD, FAY, SIMM, JONATHAN, REEVE, DOMINIC E., HALL, JIM W., SOUZA, ALEJANDRO, STANSBY, PETER K., AMOUDRY, LAURENT O., ROGERS, BENEDICT D., ELLIS, MIKE, WHITEHOUSE, RICHARD, and HORRILLO-CARABALLO, JOSE M.
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COASTAL zone management ,GEOMORPHOLOGY ,BEACH erosion ,HYDRODYNAMICS ,SEDIMENT transport ,SEA level - Published
- 2015
23. A MULTI-LANDFORM NUMERICAL FRAMEWORK FOR MODELLING LARGE SCALE COASTAL MORPHODYNAMICS.
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PAYO, ANDRES, HALL, JIM, FAVIS-MORTLOCK, DAVID, and IVES, MATTHEW
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COASTAL zone management ,COMPUTER simulation ,STRATIGRAPHIC geology ,GEOMORPHOLOGY ,EROSION - Published
- 2015
24. Experiential Lock-In: Characterizing Avoidable Maladaptation in Infrastructure Systems.
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Payo, Andres, Becker, Per, Otto, Alex, Vervoort, Joost, and Kingsborough, Ashley
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INFRASTRUCTURE (Economics) ,EXPERIENTIAL research ,ECONOMIC development ,ECONOMICS ,RESEARCH - Abstract
The article discusses ideas that characterize avoidable maladaptation in infrastructure systems. Topics discussed include the role of experiential versus analytical capacity, limits of adaptation, need to bridge impact and capacity approaches, example of avoidable lock-in, elements of avoidable lock-in and implications for infrastructure planning.
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- 2016
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25. Correction: Payo et al. Geometrical Analysis of the Inland Topography to Assess the Likely Response of Wave-Dominated Coastline to Sea Level: Application to Great Britain. J. Mar. Sci. Eng. 2020, 8 , 866.
- Author
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Payo, Andres, Williams, Chris, Vernon, Rowan, Hulbert, Andrew G., Lee, Kathryn A., and Lee, Jonathan R.
- Subjects
TOPOGRAPHY ,COASTS - Abstract
Geometrical Analysis of the Inland Topography to Assess the Likely Response of Wave-Dominated Coastline to Sea Level: Application to Great Britain. As described in Section 4.1 and Figures 10 and 11, cliff clusters 2 (4%), 3 (2%), 4 (4%), 6 (3%), 7 (6%), 9 (4%) and 10 (5%) correspond with cliff type (29% with decimals) and clusters 1 (15%), 5 (8%) and 8 (48%) are non-cliff profiles (71%). Both combined (cliff and non-cliff) add up to 100%. [Extracted from the article]
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- 2022
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26. Agricultural livelihoods in coastal Bangladesh under climate and environmental change – a model framework.
- Author
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Lázár, Attila N., Clarke, Derek, Adams, Helen, Akanda, Abdur Razzaque, Szabo, Sylvia, Nicholls, Robert J., Matthews, Zoe, Begum, Dilruba, Saleh, Abul Fazal M., Abedin, Md. Anwarul, Payo, Andres, Streatfield, Peter Kim, Hutton, Craig, Mondal, M. Shahjahan, and Moslehuddin, Abu Zofar Md.
- Abstract
Coastal Bangladesh experiences significant poverty and hazards today and is highly vulnerable to climate and environmental change over the coming decades. Coastal stakeholders are demanding information to assist in the decision making processes, including simulation models to explore how different interventions, under different plausible future socio-economic and environmental scenarios, could alleviate environmental risks and promote development. Many existing simulation models neglect the complex interdependencies between the socio-economic and environmental system of coastal Bangladesh. Here an integrated approach has been proposed to develop a simulation model to support agriculture and poverty-based analysis and decision-making in coastal Bangladesh. In particular, we show how a simulation model of farmer's livelihoods at the household level can be achieved. An extended version of the FAO's CROPWAT agriculture model has been integrated with a downscaled regional demography model to simulate net agriculture profit. This is used together with a household income–expenses balance and a loans logical tree to simulate the evolution of food security indicators and poverty levels. Modelling identifies salinity and temperature stress as limiting factors to crop productivity and fertilisation due to atmospheric carbon dioxide concentrations as a reinforcing factor. The crop simulation results compare well with expected outcomes but also reveal some unexpected behaviours. For example, under current model assumptions, temperature is more important than salinity for crop production. The agriculture-based livelihood and poverty simulations highlight the critical significance of debt through informal and formal loans set at such levels as to persistently undermine the well-being of agriculture-dependent households. Simulations also indicate that progressive approaches to agriculture (i.e. diversification) might not provide the clear economic benefit from the perspective of pricing due to greater susceptibility to climate vagaries. The livelihood and poverty results highlight the importance of the holistic consideration of the human–nature system and the careful selection of poverty indicators. Although the simulation model at this stage contains the minimum elements required to simulate the complexity of farmer livelihood interactions in coastal Bangladesh, the crop and socio-economic findings compare well with expected behaviours. The presented integrated model is the first step to develop a holistic, transferable analytic method and tool for coastal Bangladesh. [ABSTRACT FROM AUTHOR]
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- 2015
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27. Shifting perspectives on coastal impacts and adaptation.
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Brown, Sally, Nicholls, Robert J., Hanson, Susan, Brundrit, Geoff, Dearing, John A., Dickson, Mark E., Gallop, Shari L., Gao, Shu, Haigh, Ivan D., Hinkel, Jochen, Jiménez, José A., Klein, Richard J. T., Kron, Wolfgang, Lázár, Attila N., Neves, Claudio Freitas, Newton, Alice, Pattiaratachi, Charitha, Payo, Andres, Pye, Kenneth, and Sánchez-Arcilla, Agustín
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COASTAL ecology ,COASTAL ecosystem health ,ENVIRONMENTAL law ,CLIMATE change ,LAW - Abstract
The author comments on the changing attitudes and views of the international organization the Intergovernmental Panel on Climate Change (IPCC) on sea-level increases. The authors state that coastlines are dynamic attributed to the implications of climate change. They said that the situation caused problems and uncertainty in the formulation of policies and solutions to the problem.
- Published
- 2014
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28. Open Digital Shoreline Analysis System: ODSAS v1.0.
- Author
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Gómez-Pazo, Alejandro, Payo, Andres, Paz-Delgado, María Victoria, and Delgadillo-Calzadilla, Miguel A.
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TRANSECT method ,SHORELINES ,COASTAL changes ,FREEWARE (Computer software) ,COASTS - Abstract
In this study, we propose a new baseline and transect method, the open-source digital shoreline analysis system (ODSAS), which is specifically designed to deal with very irregular coastlines. We have compared the ODSAS results with those obtained using the digital shoreline analysis system (DSAS). Like DSAS, our proposed method uses a single baseline parallel to the shoreline and offers the user different smoothing and spacing options to generate the transects. Our method differs from DSAS in the way that the transects' starting points and orientation are delineated by combining raster and vector objects. ODSAS uses SAGA GIS and R, which are both free open-source software programs. In this paper, we delineate the ODSAS workflow, apply it to ten study sites along the very irregular Galician coastline (NW Iberian Peninsula), and compare it with the one obtained using DSAS. We show how ODSAS produces similar values of coastline changes in terms of the most common indicators at the aggregated level (i.e., using all transects), but the values differ when compared at the transect-by-transect level. We argue herein that explicitly requesting the user to define a minimum resolution is important to reduce the subjectivity of the transect and baseline method. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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29. Cross-shore suspended sand and bed load transport on beaches.
- Author
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Kobayashi, Nobuhisa, Payo, Andres, and Schmied, Lauren
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- 2008
- Full Text
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30. Appropriate complexity for the prediction of coastal and estuarine geomorphic behaviour at decadal to centennial scales
- Author
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French, Jon, Payo, Andres, Murray, Brad, Orford, Julian, Eliot, Matt, and Cowell, Peter
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Coastal evolution ,Systems theory ,Complexity ,Modelling ,Earth-Surface Processes - Abstract
Coastal and estuarine landforms provide a physical template that not only accommodates diverse ecosystem functions and human activities, but also mediates flood and erosion risks that are expected to increase with climate change. In this paper, we explore some of the issues associated with the conceptualisation and modelling of coastal morphological change at time and space scales relevant to managers and policy makers. Firstly, we revisit the question of how to define the most appropriate scales at which to seek quantitative predictions of landform change within an age defined by human interference with natural sediment systems and by the prospect of significant changes in climate and ocean forcing. Secondly, we consider the theoretical bases and conceptual frameworks for determining which processes are most important at a given scale of interest and the related problem of how to translate this understanding into models that are computationally feasible, retain a sound physical basis and demonstrate useful predictive skill. In particular, we explore the limitations of a primary scale approach and the extent to which these can be resolved with reference to the concept of the coastal tract and application of systems theory. Thirdly, we consider the importance of different styles of landform change and the need to resolve not only incremental evolution of morphology but also changes in the qualitative dynamics of a system and/or its gross morphological configuration. The extreme complexity and spatially distributed nature of landform systems means that quantitative prediction of future changes must necessarily be approached through mechanistic modelling of some form or another. Geomorphology has increasingly embraced so-called ‘reduced complexity’ models as a means of moving from an essentially reductionist focus on the mechanics of sediment transport towards a more synthesist view of landform evolution. However, there is little consensus on exactly what constitutes a reduced complexity model and the term itself is both misleading and, arguably, unhelpful. Accordingly, we synthesise a set of requirements for what might be termed ‘appropriate complexity modelling’ of quantitative coastal morphological change at scales commensurate with contemporary management and policy-making requirements: 1) The system being studied must be bounded with reference to the time and space scales at which behaviours of interest emerge and/or scientific or management problems arise; 2) model complexity and comprehensiveness must be appropriate to the problem at hand; 3) modellers should seek a priori insights into what kind of behaviours are likely to be evident at the scale of interest and the extent to which the behavioural validity of a model may be constrained by its underlying assumptions and its comprehensiveness; 4) informed by qualitative insights into likely dynamic behaviour, models should then be formulated with a view to resolving critical state changes; and 5) meso-scale modelling of coastal morphological change should reflect critically on the role of modelling and its relation to the observable world.
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31. Geometrical Analysis of the Inland Topography to Assess the Likely Response of Wave-Dominated Coastline to Sea Level: Application to Great Britain.
- Author
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Payo, Andres, Williams, Chris, Vernon, Rowan, Hulbert, Andrew G., Lee, Kathryn A., and Lee, Jonathan R.
- Subjects
COASTS ,SEA level ,TOPOGRAPHY ,SHORELINES ,BEACH erosion ,TIME perspective - Abstract
The need for quantitative assessments at a large spatial scale (10
3 km) and over time horizons of the order 101 to 102 years have been reinforced by the 2019 Special Report on the Ocean and Cryosphere in a Changing Climate, which concluded that adaptation to a sea-level rise will be needed no matter what emission scenario is followed. Here, we used a simple geometrical analysis of the backshore topography to assess the likely response of any wave-dominated coastline to a sea-level rise, and we applied it along the entire Great Britain (GB) coastline, which is ca. 17,820 km long. We illustrated how the backshore geometry can be linked to the shoreline response (rate of change and net response: erosion or accretion) to a sea-level rise by using a generalized shoreline Exner equation, which includes the effect of the backshore slope and differences in sediment fractions within the nearshore. To apply this to the whole of GB, we developed an automated delineation approach to extract the main geometrical attributes. Our analysis suggests that 71% of the coast of GB is best described as gentle coast, including estuarine coastline or open coasts where back-barrier beaches can form. The remaining 39% is best described as cliff-type coastlines, for which the majority (57%) of the backshore slope values are negative, suggesting that a non-equilibrium trajectory will most likely be followed as a response to a rise in sea level. For the remaining 43% of the cliffed coast, we have provided regional statistics showing where the potential sinks and sources of sediment are likely to be. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
32. Communicating Simulation Outputs of Mesoscale Coastal Evolution to Specialist and Non-Specialist Audiences.
- Author
-
Payo, Andres, French, Jon R., Sutherland, James, A. Ellis, Michael, and Walkden, Michael
- Subjects
COMPOSITION of sediments ,COASTAL engineering ,AUDIENCES ,VISUALIZATION ,SCIENTIFIC models - Abstract
Coastal geomorphologists and engineers worldwide are increasingly facing the non-trivial challenge of visualising and communicating mesoscale modelling assumptions, uncertainties and outcomes to both coastal specialists and decision-makers. Visualisation of simulation outcomes is a non-trivial problem because the more abstract scientific visualisation techniques favoured by specialists for data exploration and hypothesis-testing are not always as successful at engaging decision-makers and planners. In this paper, we show how the risk of simulation model outcomes becoming disconnected from more realistic visualisations of model outcomes can be minimised by using the Coastal Modelling Environment (CoastalME). CoastalME is a modelling framework for coastal mesoscale morphological modelling that can achieve close linkages between the scientific model abstractions, in the form of lines, areas and volumes, and the 3D representation of topographic and bathymetric surfaces and shallow sub-surface sediment composition. We propose and illustrate through the study case of Happisburgh (eastern England, UK), a transparent methodology to merge the required variety of data types and formats into a 3D-thickness model that is used to initialise a simulation. We conclude by highlighting some of the barriers to the adoption of the methodology proposed. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
33. A Quantitative Assessment of the Annual Contribution of Platform Downwearing to Beach Sediment Budget: Happisburgh, England, UK.
- Author
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Payo, Andres, Walkden, Mike, Ellis, Michael A., Barkwith, Andrew, Favis-Mortlock, David, Kessler, Holger, Wood, Benjamin, Burke, Helen, and Lee, Jonathan
- Subjects
QUATERNARY Period ,MARINE sediments ,COASTAL ecology ,MARINE resources conservation ,COASTS - Abstract
Field and numerical investigations at Happisburgh, East coast of England, UK, sought to characterize beach thickness and determine geologic framework controls on coastal change. After a major failure of coastal protection infrastructure, removal of about 1 km of coastal defence along the otherwise protected cliffed coastline of Happisburgh triggered a period of rapid erosion over 20 years of ca. 140 m. Previous sensitivity studies suggest that beach thickness plays a major role in coastal recession. These studies were limited, however, by a lack of beach volume data. In this study, we have integrated the insights gained from our understanding of the Quaternary geology of the area, a novel non-intrusive passive seismic survey method, and a 3D novel representation of the subsurface source and transportable material into a coastal modelling environment to explore the role of beach thickness on the back wearing and downwearing of the cliffs and consolidated platform, respectively. Results show that beach thickness is non-homogeneous along the study site: we estimate that the contribution to near-shore sediment budget via platform downwearing is of a similar order of magnitude as sediment lost from the beach and therefore non-negligible. We have provided a range of evidence to support the idea that the Happisburgh beach is a relatively thin layer perched on a sediment rich platform of sand and gravel. This conceptualization differs from previous publications, which assume that the platform was mostly till and fine material. This has direct implication on regional sediment management along this coastline. The present study contributes to our understanding of a poorly known aspect of coastal sediment budgeting and outlines a quantitative approach that allows for simple integration of geological understanding for coastline evolution assessments worldwide. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
34. CHEMICAL COMPOSITION AND KINETIC LAW OF THE SiO2/Si INTERFACE
- Author
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Lora-Tamayo, Amelia, Dominguez, Enrique, Lora-Tamayo, Emilio, and Payo, Andrés
- Published
- 1980
- Full Text
- View/download PDF
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