Morpho–Sedimentary Monitoring in a Coastal Area, from 1D to 2.5D, Using Airborne Drone Imagery

Dorothée James,Antoine Mury,Antoine Collin

doi:10.3390/drones3030062

Abstract

Coastal areas are among the most endangered places in the world, due to their exposure to both marine and terrestrial hazards. Coastal areas host more than two-thirds of the world’s population, and will become increasingly affected by global changes, in particular, rising sea levels. Monitoring and protecting the coastlines have impelled scientists to develop adequate tools and methods to spatially monitor morpho-sedimentary coastal areas. This paper presents the capabilities of the aerial drone, as an “all-in-one” technology, to drive accurate morpho-sedimentary investigations in 1D, 2D and 2.5D at very high resolution. Our results show that drone-related fine-resolution, high accuracies and point density outperform the state-of-the-science manned airborne passive and active methods for shoreline position tracking, digital elevation model as well as point cloud creation. We further discuss the reduced costs per acquisition campaign, the increased spatial and temporal resolution, and demonstrate the potentialities to carry out diachronic and volumetric analyses, bringing new perspectives for coastal scientists and managers.

Highlights

Our results show that drone-related fine-resolution, high accuracies and point density outperform the state-of-the-science manned airborne passive and active methods for shoreline position tracking, digital elevation model as well as point cloud creation
In order to illustrate the use of drone imagery for morpho-sedimentary monitoring, the study will focus on some sedimentary deposits mainly composed of siliceous sand and calcareous shells that play an active role into the coastal protection in the bay of Mont-Saint-Michel, France (BMSM)
The drone orthomosaic permitted to delineate the shoreline with a VHR [16,17], leveraging a pixel size of 0.016 m, whereas the 0.5 m passive airborne imagery (Ortho-littorale v2) impeded an easy visual extraction

Summary

Introduction

Due to their location at the land-sea interface and the increase of the human activity they have undergone for decades, coastal areas are among the most exposed areas worldwide to the effects of global change, especially to the ongoing and predicted sea level rise [1] as well as to the potential increase of storm intensity [2] In this context, coastal sediment deposits, like beaches, sand dunes, gravel barriers or tidal ridges, have an important role to play to protect human stakes, by acting as a natural buffer zone, thanks to their wave attenuation ability [3,4,5].

Methods

Results

Discussion

Conclusion