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

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.

The use of unmanned aerial vehicles (UAVs) for engineering geology applications

“…Another significant result of the SfM procedure is the orthophoto generation of the surveyed area. A highresolution image of the studied area is fundamental in many applications like, for example, the study of landslides (Peppa et al 2017;Fiorucci et al 2018a, b;Cignetti et al 2019), rivers (Tamminga et al 2015), or coastlines (Nikolakopoulos et al 2019).…”

Analysis of shoreline changes in Vishakhapatnam coastal tract of Andhra Pradesh, India: an application of digital shoreline analysis system (DSAS)

“…of Andhra Pradesh (2018) stated that Visakhapatnam coast have severe erosion since few decades and most of the coast has accretion and rest has eroded due severe wave action and slope of the coast. Oceanographic and meteorological conditions and geologic factors affect the phenomena of shoreline changes (Nikolakopoulos et al 2019). Vishakhapatnam District coastal tract has heterogeneous features in terms of geology, land use/land cover, (Kankara et al 2015).…”

Geoscientists in the Sky: Unmanned Aerial Vehicles Responding to Geohazards

“…In this context, one of the most important challenges will consist in combining different observation scales to understand geological processes. Combination of UAVs and space-based data has already been done in coastal line evolutions (Nikolakopoulos et al 2019), ground deformations (Cigna et al 2017) and on landslide surveys (Voigt et al 2016) and after the Mw 6.5 Lefkada earthquake (Zekkos et al 2017). These studies obtained interesting results as (1) a good estimation of the landslide volume and enabled to precisely distinguish different generation of landslides (Zekkos et al 2017), (2) an excellent georeferencing of coarse satellite images (Nikolakopoulos et al 2019) and 3information about very localized deformations (Cigna et al 2017).…”

“…Combination of UAVs and space-based data has already been done in coastal line evolutions (Nikolakopoulos et al 2019), ground deformations (Cigna et al 2017) and on landslide surveys (Voigt et al 2016) and after the Mw 6.5 Lefkada earthquake (Zekkos et al 2017). These studies obtained interesting results as (1) a good estimation of the landslide volume and enabled to precisely distinguish different generation of landslides (Zekkos et al 2017), (2) an excellent georeferencing of coarse satellite images (Nikolakopoulos et al 2019) and 3information about very localized deformations (Cigna et al 2017). However, while different applications of UAVs in preventing and reducing the risks associated with natural hazards as landslides, floods, volcanic eruptions and earthquakes exist, a few studies taking advantages of a multi-resolution data based on multi-platform sensors in post-disasters management have been made (Kakooei and Baleghi 2017;Zekkos et al 2017;Duarte et al 2018).…”