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Extreme value modeling of wind effect on dune erosion on the Coast of ̈Angelholm

Arpin-Pont, Lionel LU (2020) In LUNFMS-3087-2020 MASM01 20192
Mathematical Statistics
Abstract
The movement of the coast line, due to erosion in one direction or aggregation in theother is a natural process as waves, wind as well as the geological nature of the coast itselfare affecting it. Sand dunes are the main protection coasts have at their disposal againstfloods during storm surges or from more passive but long range rainfalls. As many of the coastal areas have a dense population and it also shows a great biodi-versity, the dune erosion is a phenomenon worth investigating since it is the destructionof such protection which is vital for everything living close-by. The cost of a flood can be measured by human loss, landscape damage or construction loss. Most of the buildings arenot suited for floods. Studying the dune erosion by... (More)
The movement of the coast line, due to erosion in one direction or aggregation in theother is a natural process as waves, wind as well as the geological nature of the coast itselfare affecting it. Sand dunes are the main protection coasts have at their disposal againstfloods during storm surges or from more passive but long range rainfalls. As many of the coastal areas have a dense population and it also shows a great biodi-versity, the dune erosion is a phenomenon worth investigating since it is the destructionof such protection which is vital for everything living close-by. The cost of a flood can be measured by human loss, landscape damage or construction loss. Most of the buildings arenot suited for floods. Studying the dune erosion by itself might not be enough to provide good advice in caseof a surge since the erosion is an effect of the surge as much as it then increases the fol-lowing risks of flooding. In order to be well prepared and build efficient methods againstsuch flooding, it is necessary to better understand the dune erosion and the surroundingphenomenon, such as the sea-level rise, the wave runups or the wind speed.The data taken for this study comes mostly from the SMHI (Swedish Meteorological andHyrological Institute), taken on or nearby the shore of ̈Angelholm in Sk ̊ane, south-west ofSweden. (Less)
Popular Abstract
Sand dunes are the natural protections lands have against
oods. Because of the wind, the waves, the water level and other climatic phenomena, dunes are subject to erosion, the same way as rock cliffs or human-built constructs.
During storm surges, i.e when the conditions are for the worst, one can expect floods due to the combination of erosion processes and sea level rise and/or wave runup.
We chose to study the sand dune erosion in the bay of Ängelholm in the
South of Sweden, using 59 spots on the shore with 40 yearly maxima for dune
erosion. The goal of this thesis was to make a better model by studying the
effect of wind on the dune erosion. The wind data comes from several stations from the SMHI (Swedish Meteorological and... (More)
Sand dunes are the natural protections lands have against
oods. Because of the wind, the waves, the water level and other climatic phenomena, dunes are subject to erosion, the same way as rock cliffs or human-built constructs.
During storm surges, i.e when the conditions are for the worst, one can expect floods due to the combination of erosion processes and sea level rise and/or wave runup.
We chose to study the sand dune erosion in the bay of Ängelholm in the
South of Sweden, using 59 spots on the shore with 40 yearly maxima for dune
erosion. The goal of this thesis was to make a better model by studying the
effect of wind on the dune erosion. The wind data comes from several stations from the SMHI (Swedish Meteorological and Hydrological Institute).
Due to the low amount of data on dune erosion, it is tedious to find a model to fit the phenomenon. Using extreme value theory allows us to only study the distribution of its maxima and hence being able to predict the so-called return levels, the maximal value that happens on average every specific period of time.
In order to fit the data well, we used various techniques to create the best model possible, such as copulas and smoothing splines. The first one joins several marginal distribution to create a joint distribution function, and the second one creates a dependence function that fits the data and the dependence function prerequisites. To create confidence intervals for our results, we re-created sets of data using the bootstrap method.
At the end of this study, with the obtained results, we can propose a functioning copula based extreme value model for dune erosion, using oriented wind speed along with worst case scenario previsions for the next 10-,100- and 200-years, which are respectively 10, 20 and 23 centimeters of eroded sand dunes on the shore of Ängelholm. (Less)
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author
Arpin-Pont, Lionel LU
supervisor
organization
course
MASM01 20192
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Erosion, Wind speed, Extreme value theory, Block maxima, Peaks over threshold, Copula, Husler-Reiss, Dependence function.
publication/series
LUNFMS-3087-2020
report number
2020:E16
ISSN
1404-6342
language
English
id
9006700
date added to LUP
2020-09-07 14:48:34
date last changed
2020-09-07 14:48:34
@misc{9006700,
  abstract     = {The movement of the coast line, due to erosion in one direction or aggregation in theother is a natural process as waves, wind as well as the geological nature of the coast itselfare affecting it. Sand dunes are the main protection coasts have at their disposal againstfloods during storm surges or from more passive but long range rainfalls. As many of the coastal areas have a dense population and it also shows a great biodi-versity, the dune erosion is a phenomenon worth investigating since it is the destructionof such protection which is vital for everything living close-by. The cost of a flood can be measured by human loss, landscape damage or construction loss. Most of the buildings arenot suited for floods. Studying the dune erosion by itself might not be enough to provide good advice in caseof a surge since the erosion is an effect of the surge as much as it then increases the fol-lowing risks of flooding. In order to be well prepared and build efficient methods againstsuch flooding, it is necessary to better understand the dune erosion and the surroundingphenomenon, such as the sea-level rise, the wave runups or the wind speed.The data taken for this study comes mostly from the SMHI (Swedish Meteorological andHyrological Institute), taken on or nearby the shore of ̈Angelholm in Sk ̊ane, south-west ofSweden.},
  author       = {Arpin-Pont, Lionel},
  issn         = {1404-6342},
  keyword      = {Erosion,Wind speed,Extreme value theory,Block maxima,Peaks over threshold,Copula,Husler-Reiss,Dependence function.},
  language     = {eng},
  note         = {Student Paper},
  series       = {LUNFMS-3087-2020},
  title        = {Extreme value modeling of wind effect on dune erosion on the Coast of ̈Angelholm},
  year         = {2020},
}