Combination of Aerial, Satellite, and UAV Photogrammetry for Mapping the Diachronic Coastline Evolution: The Case of Lefkada Island

Konstantinos Nikolakopoulos,Vasiliki Zygouri,Aggeliki Kyriou,Ioannis Koukouvelas,Dionysios Apostolopoulos

doi:10.3390/ijgi8110489

Konstantinos Nikolakopoulos, Vasiliki Zygouri + Show 3 more

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https://doi.org/10.3390/ijgi8110489

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Abstract

Coastline evolution is a proxy of coastal erosion, defined as the wasting of land along the shoreline due to a combination of natural and/or human causes. For countries with a sea border, where a significant proportion of the population lives in coastal areas, shoreline retreat has become a very serious global problem. Remote sensing data and photogrammetry have been used in coastal erosion mapping for many decades. In the current study, multi-date analogue aerial photos, digital aerial photos, and declassified satellite imagery provided by the U.S. Geological Survey (USGS), Pleiades satellite data, and unmanned aerial vehicle images were combined for accurate mapping of the southwestern Lefkada (Ionian Sea, Greece) coastline over the last 73 years. Different photogrammetric techniques were used for the orthorectifation of the remote sensing data, and geographical information systems were used in order to calculate the rates of shoreline change. The results indicated that the southwest shoreline of Lefkada Island is under dynamic equilibrium. This equilibrium is strongly controlled by geological parameters, such as subsidence of the studied shoreline during co-seismic deformation and mass wasting. The maximum accretion rate was calculated at 0.55 m per year, while the respective erosion rate reached −1.53 m per year.

Highlights

Coastal areas are defined as those where an interface or a transition between land and sea exists
Coastal erosion is the wasting of land along the shoreline due to diverse natural or human causes, such as wave action, wave and tidal currents, high winds, earthquakes, landslides, dam construction, drainage, and other human-induced causes of erosion
This research had no robust estimation of shoreline change rates because of the lack of constant and long-term monitoring

Summary

Introduction

Coastal areas are defined as those where an interface or a transition between land and sea exists. These areas constitute important and sensitive environments with significant complexity, which are, difficult to define due to their diversity in form and dynamics as well as to their spatial boundaries [1,2]. Bird (1996) estimated that 70% of sandy shorelines are eroding [4]. This research had no robust estimation of shoreline change rates because of the lack of constant and long-term monitoring. Recent studies suggest a lower rate of constant erosion for the world’s sandy beaches, in the order of 24% [5]

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