Quick Response Assessment of the Impact of an Extreme Storm Combining Aerial Drone and RTK GPS

Abstract

Abstract. Developing and implementing a quick response post-storm survey protocol has the potential to improve impact assessments of coastal storms. Pre-and post-event surveys are essential to properly quantify the storm impacts on the coast.In this study, a combination of traditional RTK GPS and Unmanned Aerial Vehicle "drone" platform was utilized as part of a coordinated storm response workflow. The comprehensive approach employed in this pilot case study was conducted on the 10 Emilia-Romagna coast (Italy), in the immediate aftermath of an extreme storm event that impacted the shoreline on the 5 th -6 th February 2015 called the "Saint Agatha Storm". The activities were supported by timing information on the approaching storm provided by the regional early warning system. We collected aerial photos from a commercial off-the-shelf drone immediately after the Saint Agatha Storm and generated both orthomosaic and digital elevation models utilizing structure-from-motion photogrammetry techniques. The drone-based survey approach allowed us to quickly survey an area of 0.25 km 2 within a 10-15 minute flight resulting in a ground sampling distance of 2.5 cm/pixel. Flooding and erosion impacts are analyzed and presented for the target study area. Limitations and possible applications for coastal management of the quick response post-storm surveying protocol are highlighted.

Experiences and results from interdisciplinary collaboration: Utilizing qualitative information to formulate disaster risk reduction measures for coastal regions

“…It was hoped to gather further expressions on disaster measures with a relatively fresh memory of the event. Much to the surprise of the research team, an unforeseen discussion arose amongst staff from the mid-and top-level civil protection agencies concerning an alert activity during the storm event of 5 February 2015 (named "St. Agatha storm"; Trembanis et al, 2017). It turned out that the roundtable discussion brought to the surface communication problems that had been overlooked during the major event of 5 February 2015 (Ciavola P. personal communication).…”

Linking source with consequences of coastal storm impacts for climate change and risk reduction scenarios for Mediterranean sandy beaches

“…The area was impacted by the event in February 2015 (see Fig. 3) with limited, but not negligible, consequences for several concessions (Perini et al, 2015;Trembanis et al, 2017).…”

“…However, extreme events can be energetic, such as the storm of September 2004 (maximum Hs = 5.65 m, estimated by Ciavola et al, 2007) or the one of 5-6 February 2015 (maximum Hs = 4.66 m, measured at the Cesenatico buoy shown Fig. 1b1; Perini et al, 2015;Trembanis et al, 2017).…”

“…offshore buoys, harbours' tide gauges, newspa-pers) along the Emilia-Romagna coast (Perini et al, 2011;Ciavola et al, 2018). The model was qualitatively validated using observed inundation extension and profile beach response of the February 2015 event (Perini et al, 2015;Trembanis et al, 2017).…”

“…Similarly, in the Mediterranean, several extreme events have impacted coastal communities at the local and regional levels such as storm Klaus in 2009, as described in Bertotti et al (2012), and cyclogenesis mechanisms in the NW Mediterranean described in Trigo et al (2002). In this context, the coasts of Catalunya (Spain) and Emilia-Romagna (Italy) also recently experienced coastal storm impacts that caused socioeconomic losses (Jiménez et al, 2012;Perini et al, 2015;Harley et al, 2016;Trembanis et al, 2017).…”