Local-scale post-event assessments with GPS and UAV-based quick-response surveys: a pilot case from the Emilia–Romagna (Italy) coast

Abstract

Abstract. Coastal communities and assets are exposed to flooding and erosion hazards due to extreme storm events, which may increase in intensity due to climatological factors in the incoming future. Coastal managers are tasked with developing risk-management plans mitigating risk during all phases of the disaster cycle. This necessitates rapid, time-efficient post-event beach surveys that collect physical data in the immediate aftermath of an event. Additionally, the inclusion of local stakeholders in the assessment process via personal interviews captures the social dimension of the impact of the event. In this study, a local protocol for post-event assessment, the quick-response protocol, was tested on a pilot site on the Emilia–Romagna (Italy) coast in the aftermath of an extreme meteorological event that occurred in February 2015. Physical data were collected using both real-time kinematic Geographical Positions Systems and unmanned aerial vehicle platforms. Local stakeholders were interviewed by collecting qualitative information on their experiences before, during, and after the event. Data comparisons between local and regional surveys of this event highlighted higher data resolution and accuracy at the local level, enabling improved risk assessment for future events of this magnitude. The local survey methodology, although improvable from different technical aspects, can be readily integrated into regional surveys for improved data resolution and accuracy of storm impact assessments on the regional scale to better inform coastal risk managers during mitigation planning.

From Hazard to Consequences: Evaluation of Direct and Indirect Impacts of Flooding Along the Emilia-Romagna Coastline, Italy

“…At present, there is not an official regional (or national) standard for data collection in the aftermath of an extreme coastal event, in order to measure flood levels and identify, collect and rigorously catalog the losses in monetary terms or structural/content damage. Standard datacollection protocols should be based on scientific studies already available at local level (e.g., Duo et al, 2018), in order to collect the necessary information that is of foremost importance to develop damage models.…”

“…The main coastal hazards are beach erosion and inundation that cause sediment loss and beach width reduction, along with damages to coastal structures and infrastructures. A major event occurred on 5-7 February 2015 (Hs = 4.6 m, Tp = 9.9 s, wave dir = ENE -measured at the Cesenatico wave rider buoy at the peak of the storm; max water level = 1.2 m measured at Porto Corsini tide gauge, Figure 1; Duo et al, 2018). This caused the extensive inundation of landward areas and impressive beach erosion.…”

“…It is reported that 50 residents of Cesenatico (Forlì-Cesena province, Figure 1) were evacuated. The event that occurred on 5-6 February 2015 was one of the most intense ever registered since 1966 (i.e., the most intense storm occurred along the RER coast; Duo et al, 2018) and caused severe damages and inundation along the whole regional area. According to newspapers articles, around 400 people were evacuated from their homes, but mostly as a preventive measure due to the high elevation, above the alert level, of the freshwater inside canals and rivers.…”

A Methodology to Assess Land Use Development, Flooding, and Wetland Change as Indicators of Coastal Vulnerability

“…We demonstrated that computing resources, software, data, and algorithms are fully capable of analyzing a large volume of data at multiple spatial scales to derive an understanding of the complex changes and the interplay among the various coastal processes at work in this area. Future research could build upon this multi-scale approach by using imagery obtained from unmanned aerial systems (UASs) at a very local scale where land cover and shoreline changes have been identified [41][42][43][44][45]. Instrumentation aboard unmanned aerial vehicles (UAVs) can provide excellent spatial resolution as well as multispectral bands; however, the coverage is limited because of battery time for overflights and access to launch and retrieve equipment can be problematic [44,45].…”

UAV Photogrammetry and Ground Surveys as a Mapping Tool for Quickly Monitoring Shoreline and Beach Changes

“…The geomatic surveying methods, such as aero photogrammetric surveys [7,8], unmanned aerial vehicle (UAV) [9][10][11][12][13][14][15], remote sensing with satellite images [12,16], airborne light detection and ranging (LiDAR) [17][18][19][20][21][22], synthetic aperture radar (SAR) [23,24], video systems [25][26][27][28][29] are widespread techniques to measure wide areas, generate digital terrain models (DTMs) and maps, and to quantify coastal changes by multi-temporal comparisons.…”