Assessment of Remote Sensing Techniques Applicability for Beach Morphology Mapping: A Case Study of Hvar Island, Central Adriatic, Croatia

Sanja Faivre,Mateo Gašparović,Marin Mićunović

doi:10.3390/jmse9121407

Abstract

This study investigates the quality and accuracy of remote sensing data in beach surveys based on three different data sources covering a 10-year period (2011–2021). Orthophotos from State Geodetic Administration Geoportal and satellite imagery from Google Earth were compared with orthophotos generated from UAV using ArcGIS Pro and Drone2Map. The beach area and length of 20 beaches on the island of Hvar were measured using each data source from different years. The average deviation for beach area (−2.3 to 5.6%) and length (−1 to 2.7%) was determined (without outliers). This study confirms that linear feature measurement is more accurate than polygon-based measurement. Hence, smaller beach areas were associated with higher errors. Furthermore, it was observed that morphological complexity of the beach may also affect the measurement accuracy. This work showed that different remote sensing sources could be used for relatively accurate beach surveys, as there is no statistically significant difference between the calculated errors. However, special care should always be addressed to the definition of errors.

Highlights

IntroductionBeaches in particular, are dynamic geomorphological features that are constantly changing
Coastal areas, and beaches in particular, are dynamic geomorphological features that are constantly changing
This study investigates the quality and accuracy of remote sensing data in beach surveys based on three different data sources covering a 10-year period (2011–2021)

Summary

Introduction

Beaches in particular, are dynamic geomorphological features that are constantly changing. Natural processes, such as waves, tides, rainfalls, relative sea-level changes, combined with anthropogenic activities, lead to changes in the morphological characteristics of beaches. Beaches make up 40% of the world’s coastline, 70% of which are subject to erosion [1]. More precision is recently provided for sandy beaches revealing that 24% of them are subject to erosion, and 28% are prograding, while 48% are relatively stable [2]. Growing anthropic pressures combined with climate change and sea-level change, e.g., as in References [3,4,5,6,7], makes beaches today highly vulnerable features

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