New Developments in Global Beach Erosion Assessment

New Developments in Global Beach Erosion Assessment

Cowan, Thomas (TU Delft Civil Engineering and Geosciences)

Aarninkhof, S.G.J. (graduation committee)
de Vries, S. (graduation committee)
Nicholls, R.J. (graduation committee)
Hagenaars, Gerben (graduation committee)
Luijendijk, A.P. (mentor)

Delft University of Technology
University of Southampton
Norwegian University of Science and Technology (NTNU)

Coastal and Marine Engineering and Management (CoMEM)

2018-07-17

Sea Level Rise is anticipated to significantly affect human development in the coastal zone by the end of the Twenty-First Century. The rising waters bring greater risk of floods, submergence of low lying land, salinization of freshwater supplies, and the erosion of sandy beaches. Quantifying these impacts spurns action by those hoping to adapt to changing environmental conditions, but sea level rise acts at such large scales that this quantification proves difficult. Dynamic Interactive Vulnerability Analysis (DIVA) provides this capacity by modelling the growth of society parallel to environmental forcing from IPCC scenarios and human adaptation measures in the coastal zone. This thesis attempts to use new information and technology to expand existing tools which quantify the impacts of beach erosion due to sea level rise and human adaptation using beach nourishment on a global scale. This echoes earlier work by (Hinkel et al., 2013). To accomplish this task, a methodology is developed to conduct and aggregate large amounts of information into the DIVA coastal database, and a secondary global risk model develops refined nourishment adaptation cost information.
Data collection over the large scales covered by the DIVA model is difficult, and existing approximations within the model are categorically applied to poorly resolved datasets and archived information. Recent developments in remote sensing created a new database which indicates the location of beaches at a global scale. The utility of this information is the primary motivation for this study. Similarly, adaptation costs in DIVA are not well resolved, and available expert judgment is leveraged to allow more insight into these practices.
These modifications have complex individual interactions with human coastal development, and simple superposition is not an effective tool to predict their combined impact. The locations most significantly impacted by the modifications are typically island states previously categorized without beaches. Adaptation favors wealthy locations with a large population density. The costs of lost land and forced migration in these areas outweigh adaptation costs by substantial margins in some cases, and nourishment .
Recreation of the Hinkel et al. study is not possible with the current DIVA architecture, and the lack of reasoned relation to this work limits interpretation. As a large scale model using aggregated parameters, DIVA is limited by its ignorance of local-level processes. Further limitations include a lack of resolved information for secondary erosive forcing from tidal basins, whose impacts are included, yet not specifically addressed.
DIVA does address the question of vulnerability at a national level, and can inform decision makers on the costs and protections provided through adaptation. It can highlight the growth and development of adaptation measures in response to sea level rise and weigh them against the cost of inaction. In doing so, DIVA highlights areas where pretection is economically feasible and viable for the mitigation of sea-level-rise-induced beach erosion.

Sea level rise
DIVA
Beach erosion
Global assessment

http://resolver.tudelft.nl/uuid:aab227ad-0e9d-4372-8718-5080d486781c

2019-04-01

The Erasmus+: Erasmus Mundus MSc in Coastal and Marine Engineering and Management is an integrated programme including mobility organized by five European partner institutions, coordinated by Norwegian University of Science and Technology (NTNU).

Student theses

master thesis

© 2018 Thomas Cowan