Using UAV to Capture and Record Torrent Bed and Banks, Flood Debris, and Riparian Areas

Paschalis Koutalakis,Ourania Tzoraki,George N Zaimes,Giorgos Gkiatas

doi:10.3390/drones4040077

Paschalis Koutalakis, Ourania Tzoraki + Show 2 more

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https://doi.org/10.3390/drones4040077

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Abstract

Capturing and recording fluvio-geomorphological events is essential since these events can be very sudden and hazardous. Climate change is expected to increase flash floods intensity and frequency in the Mediterranean region, thus enhancing such events will also impact the adjacent riparian vegetation. The aim of this study was to capture and record the fluvial-geomorphological changes of the torrent bed and banks and flood debris events with the use of UAV images along a reach of Kallifytos torrent in northern Greece. In addition, a novel approach to detecting changes and assessing the conditions of the riparian vegetation was conducted by using UAV images that were validated with field data based on a visual protocol. Three flights were conducted using the DJI Spark UAV. Based on the images collected from these flights, orthomosaics were developed. The orthomosaics clearly identified changes in the torrent bed and detected debris flow events after major flood events. In addition, the results on the assessment of riparian vegetation conditions were satisfactory. Utilizing UAV images shows great potential to capture, record, and monitor fluvio-geomorphological events and riparian vegetation. Their utilization would help water managers to develop more sustainable management solutions based on actual field data.

Highlights

Fluvio-geomorphological events can be very sudden and episodic [1], indicating that new innovative methods need to be utilized for their more effective recording and monitoring [2]
The research in this study focuses on the sub-urban part of the Kallifytos torrent (Lat. 41◦ 80 48.29” N and Long. 24◦ 100 19.85” E), a typical ephemeral Greek torrent that has flash flood risk potential after heavy rainfalls
Thirty equidistant sites were surveyed based on the field measurements starting downstream from the bridge that our study focused on and continuing upstream

Summary

Introduction

Fluvio-geomorphological events can be very sudden and episodic [1], indicating that new innovative methods need to be utilized for their more effective recording and monitoring [2]. Of major interest are stream bed and stream bank changes and flood debris events as they can alter the channel flow path and cause major infrastructure failures. In the Mediterranean region, these are primarily caused by flash floods [3]. As flash floods are weather-related events (primarily the results of intense rainfall events), they are expected to be affected by climate change [6]. Their frequency and magnitude will be increased due to more extreme weather events caused by climate change such as extreme rainfall events [7,8]. One of the most vulnerable regions to climate change is the Mediterranean

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