Coastal risk forecast system : fostering proactive management at the Catalan coast

Aplicat embargament des de la data de defensa fins Juliol 2020.The action of sea storms is one of the most complex littoral processes with deep management implications. Along the Catalan shoreline which is about 700 km long, 190 km are subject to erosion and/or flooding. Around one million people live in areas potentially affected. Sea Level Rise could exacerbate this problem in the near future. Reactive interventions have been the norm in coastal engineering and management. This dissertation proposes a pre-storm strategy that foster cost-effective eco-compatible measures, termed Quick Defence Measures (QDM). Pre-storm intervention requires to forecast the future post-storm state. Hence, the main objective of this thesis is to assess present coastal risk through a Coastal Early Warning System (CEWS), termed LIM-COPAS, that forecasts the more relevant episodic coastal hazards at the area. LIM-COPAS consists of four modules: (i) meteorological model; (ii) wave generation/propagation code; (iii) coupled morpho-hydrodynamic model and (iv) risk module via non-stationary multivariate probabilistic models. The performance of this suite of models has been tested with (i) a set of hindcast events and (ii) synthetic storm conditions. The hindcasted events have been: December 2008 (D-08); October-2015 (O-15); November 2015 (N-15); January 2016 (J-16); February 2016 (F-16); December 2016 (D-16) and January 2017 (J-17). In D-08, errors in nearshore spectral wave parameters have been about twice than those in the offshore area. The error was around 20% in hydrodynamics and 50% in morphodynamics. The post-storm response has been acceptably reproduced, with a Brier Skill Score near 0.4. LIM-COPAS has shown good accuracy with high return period events (i.e. Tr,waves > 10 yrs, D-16 and J-17), but lower agreement was found for milder storms (i.e. O-15 and F-16). The meteorological module provided wind fields that were systematically overestimated. The integrated Mean Bias (MB) was -1.52 ± 0.78 m/s. Tarragona (Coefficient of Efficiency, COE = 0.27 ± 0.13) and Begur (COE = 0.29 ± 0.17) had metrics above the average value (COE = 0.24 ± 0.14); but lower agreement was found at Mahón (COE = 0.13 ± 0.16) and Dragonera. Wave metrics were more accurate than for the wind fields. The integrated Hs COE was 0.52±0.12 and Tm02 COE was 0.36±0.14. At the central coast, Hs has presented good metrics: low MB (-0.06 ± 0.08 m) and high COE (0.58 ± 0.11). The northern coast metrics were the most stable. The newly developed risk module has been implemented at 79 beaches. Erosion has been estimated as a bounded cost, whereas flooding as a high upside cost. Dissipative beaches tend to exhibit higher costs than reflective beaches under high sea levels. Tr,waves < 10 yrs events joint with storm-surges can lead to significant damage costs. The estimated losses for the N-15 event (2510·10^3 euros) do not differ excessively from J-17 (3200·10^3 euros). Two types of QDM have been numerically tested: (i) sand dunes and (ii) geotextile detached breakwaters. The benefits from maintaining the sand volumes outperform the flooding cost reduction. In general terms, the detached breakwater can be a suitable option for beaches in an intermediate morphodynamic state against low to moderate sea levels and high wave return periods. At dissipative beaches, dunes are the best option, but they require a minimum beach width (around 30 m) that ensures their lifetime. QDM functionality can be enhanced with compatible long-term actions (nourishments, sand bypasses, submerged vegetation, etc.). A healthy beach state is paramount for the QDM effectiveness. A higher sustainable management under present and future climate can be reached with the joint combination of (i) CEWS as a short-term forecasting tool; (ii) QDM that mitigate storm impacts and (iii) long-term interventions that improves the beach health.La acción de los temporales de mar es uno de los procesos litorales más complejos, con profundas implicaciones en la gestión del litoral. A lo largo de la línea de costa catalana, 190 km están sometidos a erosión y/o inundación. Cerca de un millón de personas viven en áreas potencialmente afectadas. La tradición en ingeniería y gestión costera han sido intervenciones reactivas. Esta tesis propone una estrategia pre-tormenta que fomente una serie de medidas eco-compatibles, denominadas Medidas de Acción Rápida (MAR). Las intervenciones pre-tormenta requieren predecir el estado post-temporal de la costa. Por tanto, el principal objetivo de esta tesis es evaluar el riesgo costero episódico mediante un Sistema de Alarma Temprana Costero (CEWS), denominado LIM-COPAS, que predice las peligrosidades costeras más relevantes en dicha área. LIM-COPAS consiste de cuatro módulos: (i) modelo meteorológico; (ii) código de generación/propagación del oleaje; (iii) modelo acoplado morfo-hidrodinámico y (iv) un módulo de riesgo vía modelos probabilísticos multivariantes y no-estacionarios. El comportamiento de estos módulos ha sido analizado mediante (i) una serie de eventos pasados y (ii) temporales sintéticos. Los eventos pasados han sido: Diciembre 2008 (D-08); Octubre 2015 (O-15); Noviembre 2015 (N-15); Enero 2016 (J-16); Febrero 2016 (F-16); Diciembre 2016 (D-16) y Enero 2017 (J-17). En D-08, los errores en los parámetros espectrales de oleaje costero han sido casi el doble que en mar abierto. El error ha sido del 20% en la hidrodinámica y del 50% en la morfodinámica. La respuesta post-temporal ha sido reproducida aceptablemente, con Brier Skill Score cercanos a 0.4. LIM-COPAS ha demostrado buena precisión con tormentas de alto período de retorno (i.e. Tr,waves _ 10 yrs, D-16 y J-17), pero menor concordancia fue encontrada para las tormentas moderadas (i.e. O-15 y F-16). El módulo meteorológico estimó campos de viento que fueron sistemáticamente sobreestimados. El Sesgo Medio (MB) integrado fue de −1,52 ± 0,78 m/s. Tarragona (Coeficiente de Eficiencia, COE = 0,27±0,13) y Begur (COE = 0,29±0,17) tuvieron métricas por encima de la media (COE = 0,24±0,14); no obstante, peor ajuste se encontró en Mahón (COE = 0,13 ± 0,16) y Dragonera. Las métricas de oleaje fueron más precisas que las del viento. Hs COE integrada fue 0,52±0,12 y Tm02 COE fue 0,36±0,14. En la costa central, Hs presentó buenas métricas: bajo MB (−0,06 ± 0,08 m) y alto COE (0,58 ± 0,11). Las métricas en la costa norte fueron las más estables. El módulo de riesgo ha sido implementado en 79 playas. La erosión se ha estimado como un coste acotado, mientras que la inundación como un coste con alta cota superior. Las playas disipativas tienden a exhibir mayores costes que las playas reflejantes bajo altos niveles del mar. Episodios con Tr,waves _ 10yrs, concomitantes a mareas meteorológicas pueden conllevar costes significantes. Las pérdidas estimadas para N-15 (2510 · 103euros) no difieren en exceso de J-17 (3200 · 103 euros). Dos tipos de MAR han sido testeadas numéricamente: (i) dunas y (ii) diques exentos constituídos por geotextiles llenos de arena. Los beneficios de mantener estables los volúmenes de arena superan la reducción de los costes por inundación. En términos generales, los diques exentos pueden ser una opción adecuada para playas de estado morfodinámico intermedio frente a oleaje de alto período de retorno y niveles del mar bajos a moderados. En playas disipativas, las dunas son la mejor opción, pero requieren un ancho mínimo de playa (cerca de 30 m) que garantice su vida útil. La funcionalidad de las MAR puede mejorarse mediante acciones compatibles a largo-plazo (alimentaciones, bypass de arena, vegetación sumergida, etc.). Un estado de playa saludable es esencial para la efectividad de las MAR. Una gestión más sostenible bajo clima presente y futuro puede ser alcanzada mediante (i) CEWS como herramienta de predicción a corto plazo; (ii) MAR que mitiguen los impactos de los temporales y (iii) intervenciones a largo-plazo que mejoren la salud de la costa.Postprint (published version

Coastal risk forecast system : fostering proactive management at the Catalan coast

The action of sea storms is one of the most complex littoral processes with deep management implications. Along the Catalan shoreline which is about 700 km long, 190 km are subject to erosion and/or flooding. Around one million people live in areas potentially affected. Sea Level Rise could exacerbate this problem in the near future. Reactive interventions have been the norm in coastal engineering and management. This dissertation proposes a pre-storm strategy that foster cost-effective eco-compatible measures, termed Quick Defence Measures (QDM). Pre-storm intervention requires to forecast the future post-storm state. Hence, the main objective of this thesis is to assess present coastal risk through a Coastal Early Warning System (CEWS), termed LIM-COPAS, that forecasts the more relevant episodic coastal hazards at the area. LIM-COPAS consists of four modules: (i) meteorological model; (ii) wave generation/propagation code; (iii) coupled morpho-hydrodynamic model and (iv) risk module via non-stationary multivariate probabilistic models. The performance of this suite of models has been tested with (i) a set of hindcast events and (ii) synthetic storm conditions. The hindcasted events have been: December 2008 (D-08); October-2015 (O-15); November 2015 (N-15); January 2016 (J-16); February 2016 (F-16); December 2016 (D-16) and January 2017 (J-17). In D-08, errors in nearshore spectral wave parameters have been about twice than those in the offshore area. The error was around 20% in hydrodynamics and 50% in morphodynamics. The post-storm response has been acceptably reproduced, with a Brier Skill Score near 0.4. LIM-COPAS has shown good accuracy with high return period events (i.e. Tr,waves > 10 yrs, D-16 and J-17), but lower agreement was found for milder storms (i.e. O-15 and F-16). The meteorological module provided wind fields that were systematically overestimated. The integrated Mean Bias (MB) was -1.52 ± 0.78 m/s. Tarragona (Coefficient of Efficiency, COE = 0.27 ± 0.13) and Begur (COE = 0.29 ± 0.17) had metrics above the average value (COE = 0.24 ± 0.14); but lower agreement was found at Mahón (COE = 0.13 ± 0.16) and Dragonera. Wave metrics were more accurate than for the wind fields. The integrated Hs COE was 0.52±0.12 and Tm02 COE was 0.36±0.14. At the central coast, Hs has presented good metrics: low MB (-0.06 ± 0.08 m) and high COE (0.58 ± 0.11). The northern coast metrics were the most stable. The newly developed risk module has been implemented at 79 beaches. Erosion has been estimated as a bounded cost, whereas flooding as a high upside cost. Dissipative beaches tend to exhibit higher costs than reflective beaches under high sea levels. Tr,waves < 10 yrs events joint with storm-surges can lead to significant damage costs. The estimated losses for the N-15 event (2510·10^3 euros) do not differ excessively from J-17 (3200·10^3 euros). Two types of QDM have been numerically tested: (i) sand dunes and (ii) geotextile detached breakwaters. The benefits from maintaining the sand volumes outperform the flooding cost reduction. In general terms, the detached breakwater can be a suitable option for beaches in an intermediate morphodynamic state against low to moderate sea levels and high wave return periods. At dissipative beaches, dunes are the best option, but they require a minimum beach width (around 30 m) that ensures their lifetime. QDM functionality can be enhanced with compatible long-term actions (nourishments, sand bypasses, submerged vegetation, etc.). A healthy beach state is paramount for the QDM effectiveness. A higher sustainable management under present and future climate can be reached with the joint combination of (i) CEWS as a short-term forecasting tool; (ii) QDM that mitigate storm impacts and (iii) long-term interventions that improves the beach health.La acción de los temporales de mar es uno de los procesos litorales más complejos, con profundas implicaciones en la gestión del litoral. A lo largo de la línea de costa catalana, 190 km están sometidos a erosión y/o inundación. Cerca de un millón de personas viven en áreas potencialmente afectadas. La tradición en ingeniería y gestión costera han sido intervenciones reactivas. Esta tesis propone una estrategia pre-tormenta que fomente una serie de medidas eco-compatibles, denominadas Medidas de Acción Rápida (MAR). Las intervenciones pre-tormenta requieren predecir el estado post-temporal de la costa. Por tanto, el principal objetivo de esta tesis es evaluar el riesgo costero episódico mediante un Sistema de Alarma Temprana Costero (CEWS), denominado LIM-COPAS, que predice las peligrosidades costeras más relevantes en dicha área. LIM-COPAS consiste de cuatro módulos: (i) modelo meteorológico; (ii) código de generación/propagación del oleaje; (iii) modelo acoplado morfo-hidrodinámico y (iv) un módulo de riesgo vía modelos probabilísticos multivariantes y no-estacionarios. El comportamiento de estos módulos ha sido analizado mediante (i) una serie de eventos pasados y (ii) temporales sintéticos. Los eventos pasados han sido: Diciembre 2008 (D-08); Octubre 2015 (O-15); Noviembre 2015 (N-15); Enero 2016 (J-16); Febrero 2016 (F-16); Diciembre 2016 (D-16) y Enero 2017 (J-17). En D-08, los errores en los parámetros espectrales de oleaje costero han sido casi el doble que en mar abierto. El error ha sido del 20% en la hidrodinámica y del 50% en la morfodinámica. La respuesta post-temporal ha sido reproducida aceptablemente, con Brier Skill Score cercanos a 0.4. LIM-COPAS ha demostrado buena precisión con tormentas de alto período de retorno (i.e. Tr,waves _ 10 yrs, D-16 y J-17), pero menor concordancia fue encontrada para las tormentas moderadas (i.e. O-15 y F-16). El módulo meteorológico estimó campos de viento que fueron sistemáticamente sobreestimados. El Sesgo Medio (MB) integrado fue de −1,52 ± 0,78 m/s. Tarragona (Coeficiente de Eficiencia, COE = 0,27±0,13) y Begur (COE = 0,29±0,17) tuvieron métricas por encima de la media (COE = 0,24±0,14); no obstante, peor ajuste se encontró en Mahón (COE = 0,13 ± 0,16) y Dragonera. Las métricas de oleaje fueron más precisas que las del viento. Hs COE integrada fue 0,52±0,12 y Tm02 COE fue 0,36±0,14. En la costa central, Hs presentó buenas métricas: bajo MB (−0,06 ± 0,08 m) y alto COE (0,58 ± 0,11). Las métricas en la costa norte fueron las más estables. El módulo de riesgo ha sido implementado en 79 playas. La erosión se ha estimado como un coste acotado, mientras que la inundación como un coste con alta cota superior. Las playas disipativas tienden a exhibir mayores costes que las playas reflejantes bajo altos niveles del mar. Episodios con Tr,waves _ 10yrs, concomitantes a mareas meteorológicas pueden conllevar costes significantes. Las pérdidas estimadas para N-15 (2510 · 103euros) no difieren en exceso de J-17 (3200 · 103 euros). Dos tipos de MAR han sido testeadas numéricamente: (i) dunas y (ii) diques exentos constituídos por geotextiles llenos de arena. Los beneficios de mantener estables los volúmenes de arena superan la reducción de los costes por inundación. En términos generales, los diques exentos pueden ser una opción adecuada para playas de estado morfodinámico intermedio frente a oleaje de alto período de retorno y niveles del mar bajos a moderados. En playas disipativas, las dunas son la mejor opción, pero requieren un ancho mínimo de playa (cerca de 30 m) que garantice su vida útil. La funcionalidad de las MAR puede mejorarse mediante acciones compatibles a largo-plazo (alimentaciones, bypass de arena, vegetación sumergida, etc.). Un estado de playa saludable es esencial para la efectividad de las MAR. Una gestión más sostenible bajo clima presente y futuro puede ser alcanzada mediante (i) CEWS como herramienta de predicción a corto plazo; (ii) MAR que mitiguen los impactos de los temporales y (iii) intervenciones a largo-plazo que mejoren la salud de la costa

Weather and Climate Information for Tourism

The tourism sector is one of the largest and fastest growing global industries and is a significant contributor to national and local economies around the world. The interface between climate and tourism is multifaceted and complex, as climate represents both a vital resource to be exploited and an important limiting factor that poses risks to be managed by the tourism industry and tourists alike. All tourism destinations and operators are climate-sensitive to a degree and climate is a key influence on travel planning and the travel experience. This chapter provides a synopsis of the capacities and needs for climate services in the tourism sector, including current and emerging applications of climate services by diverse tourism end-users, and a discussion of key knowledge gaps, research and capacity-building needs and partnerships that are required to accelerate the application of climate information to manage risks to climate variability and facilitate successful adaptation to climate change

Weather and Climate Information for Tourism

The tourism sector is one of the largest and fastest growing global industries and is a significant contributor to national and local economies around the world. The interface between climate and tourism is multifaceted and complex, as climate represents both a vital resource to be exploited and an important limiting factor that poses risks to be managed by the tourism industry and tourists alike. All tourism destinations and operators are climate-sensitive to a degree and climate is a key influence on travel planning and the travel experience. This chapter provides a synopsis of the capacities and needs for climate services in the tourism sector, including current and emerging applications of climate services by diverse tourism end-users, and a discussion of key knowledge gaps, research and capacity-building needs and partnerships that are required to accelerate the application of climate information to manage risks to climate variability and facilitate successful adaptation to climate change

Weather and Climate Information for Tourism

The tourism sector is one of the largest and fastest growing global industries and is a significant contributor to national and local economies around the world. The interface between climate and tourism is multifaceted and complex, as climate represents both a vital resource to be exploited and an important limiting factor that poses risks to be managed by the tourism industry and tourists alike. All tourism destinations and operators are climate-sensitive to a degree and climate is a key influence on travel planning and the travel experience. This chapter provides a synopsis of the capacities and needs for climate services in the tourism sector, including current and emerging applications of climate services by diverse tourism end-users, and a discussion of key knowledge gaps, research and capacity-building needs and partnerships that are required to accelerate the application of climate information to manage risks to climate variability and facilitate successful adaptation to climate change

Comparison between nested grids and unstructured grids for a high-resolution wave forecasting system in the western Mediterranean sea

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Journal of Operational Oceanography on 2017, available online at: http://www.tandfonline.com/10.1080/1755876X.2016.1260389Traditionally wave modelling uses a downscaling process by means of successive nested grids to obtain high-resolution wave fields near the coast. This supposes an uncertain error due to internal boundary conditions and a long computational time. Unstructured grids avoid multiple meshes and thus the problem of internal boundary conditions. In the present study high resolution wave simulations are analysed for a full year where high-resolution meteorological models were available in the Catalan coast. This coastal case presents sharp gradients in bathymetry and orography and therefore correspondingly sharp variations in the wind and wave fields. Simulations with SWAN v.4091A using a traditional nested sequence and a regional unstructured grid have been compared. Also a local unstructured grid nested in an operational forecast system is included in the analysis. The obtained simulations are compared to wave observations from buoys near the coast; almost no differences are found between the unstructured grids and the regular grids. Simultaneously, tests have been carried out in order to analyse the computational time required for each of the alternatives, showing a decrease to less than half the time when working with regional unstructured grids and maintaining the forecast accuracy and coastal resolution with respect to the downscaling system.Peer ReviewedPostprint (author's final draft

Oceanographic Weather Maps: Using Oceanographic Models to Improve Seabed Mapping Planning and Acquisition

In a world of high precision sensors, one of the few remaining challenges in multibeam echosounding is that of refraction based uncertainty. A poor understanding of oceanographic variability can lead to inadequate sampling of the water mass and the uncertainties that result from this can dominate the uncertainty budget of even state-of-the-art echosounding systems. Though dramatic improvements have been made in sensor accuracies over the past few decades, survey accuracy and efficiency is still potentially limited by a poor understanding of the “underwater weather”. Advances in the sophistication of numerical oceanographic forecast modeling, combined with ever increasing computing power, allow for the timely operation and dissemination of oceanographic nowcast and forecast model systems on regional and global scales. These sources of information, when examined using sound speed uncertainty analysis techniques, have the potential to change the way hydrographers work by increasing our understanding of what to expect from the ocean and when to expect it. Sound speed analyses derived from ocean modeling system’s three-dimensional predictions could provide guidance for hydrographers during survey planning, acquisition and post-processing of hydrographic data. In this work, we examine techniques for processing and visualizing of predictions from global and regional operational oceanographic forecast models and climatological analyses from an ocean atlas to better understand how these data could best be put to use to in the field of hydrograph

Climate Services to Support Sustainable Tourism and Adaptation to Climate Change

Tourism is one of the largest global economic sectors, is a vital contributor to the economy of many nations, and is highly promoted as an important means of future development and poverty reduction in developing countries. The interface between climate and tourism is multifaceted and complex, with broad significance for tourist decision-making and expenditures, as well as industry marketing and operations worldwide. With the close relationship of tourism to the environment and climate, the integrated effects of climate change are anticipated to markedly affect tourism businesses and destinations, as well as the destination choices and mobility of individual tourists in the decades ahead. As recent major natural, political, and economic shocks have demonstrated, the tourism sector has relatively high adaptive capacity. Improved climate services will be vital for travelers and tourism businesses and destinations to adapt to climate change in an economically, socially, and environmentally sustainable manner. This paper outlines the range of applications of weather and climate information within the tourism sector and discusses priorities for future work to advance climate services for weather risk management and climate change adaptation for the tourism sector