Centre de documentation
scientifique

Beach morphology and its dynamism from remote sensing for coastal management support / Carlos Cabezas Rabadán (2021)  

Public Titre : Beach morphology and its dynamism from remote sensing for coastal management support Type de document : Thèse/HDR Auteurs : Carlos Cabezas Rabadán, Auteur ; Josep E. Pardo Pascual, Directeur de thèse ; Miguel Rodilla Alamá, Directeur de thèse Editeur : Valencia : Universitat politécnica de Valencia Année de publication : 2021 Importance : 188 p. Format : 21 x 30 cm Note générale : bibliographie Thesis dissertation submitted in fulfillment of the requirements for the Degree of Doctor of Philosophy at Universitat Politècnica de València Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] changement climatique [Termes IGN] détection de changement [Termes IGN] érosion côtière [Termes IGN] géomorphologie [Termes IGN] image Landsat [Termes IGN] image Sentinel-MSI [Termes IGN] modélisation spatio-temporelle [Termes IGN] plage [Termes IGN] sédiment [Termes IGN] surveillance du littoral [Termes IGN] trait de côte Résumé : (auteur) Beaches are coastal spaces that perform numerous environmental functions. They provide important benefits to society and coastal communities, including the ecological function, the provision of protection for coastal territories, and constitute a basic resource for the tourism industry. Due to climate change and human actions that alter the natural dynamism of the coast, beaches are experiencing increasingly harmful erosive processes that affect their physical integrity and the maintenance of their ecological functions. Beach management is often not adapted to the particularities of the different coastal segments. Decision-making is not based on sufficient information about characteristics, dynamism, and current state of beaches, resulting in short or ineffective solutions. Geomorphological characteristics are essential in the development of beach functions as they condition their physical dimensions and their behavior in response to the action of the sea. Therefore, their detailed and updated characterization is necessary to carry out efficient actions, allowing a more ecosystemic and sustainable coastal management. Remote sensing techniques have a great capacity for acquiring data from the land surface. In particular, Sentinel-2 and Landsat (5, 7, and 8) satellites freely provide medium resolution images with global coverage and high-revisit frequency. The algorithms for extracting the water/land interface recently developed by the Geo-Environmental Cartography and Remote Sensing Group (CGAT – UPV) allow defining the position of the shoreline on these images, constituting potentially useful data to describe beach morphology and dynamics. Universalizing their application requires testing and validation at different coastal types. For this purpose, the extraction process has been adapted for exploitation in tidal environments, and the resulting shorelines have been assessed under different oceanographic conditions offering an accuracy close to 5 m RMSE (Root-Mean-Square Error). From these shorelines, and taking into account the existing information needs for management, it is proposed to derive indicators to characterize the geomorphology of the beaches and to monitor their changes. To this end, the proposed methodologies ensure the efficient management of large volumes of shorelines, being able to characterize the beaches along broad coastal segments and periods. Thus, beach width and sediment grain size are derived as objective and easily understandable indicators of the beach geomorphology. Spatial-temporal modeling of the state and changes of shoreline position and beach width makes it possible to monitor the response to storms and anthropogenic actions, allowing to analyze changes that occur every few days or over decades. The large spatial coverage together with the integration with other cartographic databases allows characterizing the influence of beach geomorphology in the performance of its functions, offering a holistic view of the coast from a regional scale. The methodologies developed in this thesis and the indicators derived from remote sensing provide support and criteria for prioritizing the actions of managers. This contributes to fill the gap between the availability of techniques to obtain remote information and its application in the coastal decision-making process. Note de contenu : 1- General introduction 2- Assessing user’s expectations and perceptions on different beach types and the need for diverse management frameworks 3- Satellite-derived shorelines at an exposed mesotidal beach 4- Characterizing beach changes using satellite-derived shorelines 5- Detecting problematic beach widths for the recreational function from subpixel shoreline 6- Shoreline variability from Sentinel-2: an approach for estimating beach sediment size? 7- Conclusions, management implications and future perspectives Numéro de notice : 28599 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse étrangère Note de thèse : PhD Thesis : Geomatics : Valencia, Spain : 2021 DOI : 10.4995/Thesis/10251/165076 En ligne : https://doi.org/10.4995/Thesis/10251/165076 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99405