Some results of coastal defences monitoring by ground laser scanning technology

Abstract

A general coastal retreat affects almost all the beaches of the Apulia region (southern Italy). In particular, the coastal strip of the Gulf of Manfredonia shows an evident retreat due to human activity. To control coastal erosion, several defence interventions have been realised: breakwaters, shore parallel defences, and, above all, sev- eral types of groynes (rectilinear, hook-shaped, T-shaped) were built along the shoreline in accordance with local request. Nowadays, there are about 300 coastal defences built up to protect against human activities. A laser scanner survey of these defences, using a Leica Geosystems HDS3000, was carried out between April 2006 and September 2008 to collect data about the beach profiles and changes occurring in the defence framework. The survey work consists of 3D rendering of defences in order to make comparisons between scans of different periods. Overlap between the points cloud of the whole coastline showed that defences preserved their own profile when no human interventions took place. Moreover, throughout the length of the investigated area, not a single trend occurred in the beach profile: according to the defence framework, some stretches of coast display advancing trend, while others are stable or retreating. Therefore, this preliminary study indicated that the changes that occurred in the beach pro- files and defence structures are mainly due to human interventions

Linking sardine recruitment in coastal areas to ocean currents using surface drifters and HF radar: a case study in the Gulf of Manfredonia, Adriatic Sea

“…Also the Palagruža Islands SA has an overall low connection with the gulf, even though it is one of the closest SAs from a geographical point of view. This is an example of the difference between geographic distance and "oceanographic distance" (Jönsson and Watson, 2016), which is related to the transport time due to the current and whose importance has been pointed out in several biological applications. The Palagruža Islands SA is indeed one of the farthest SAs from the oceanographic point of view, likely because it is only occasionally involved in the eastward limb of the central sub-basin gyre, which has high variability and reduced transport with respect to the most prominent westward arm (Carlson et al, 2016).…”

Morpho-sedimentary dynamics of Torre Guaceto beach (Southern Adriatic Sea, Italy)

“…The speciBc literature contains recent studies on geomorphological and morphodynamic characteristics of the Apulian coast (Caldara et al 1998;) and its relation with the urbanisation issue. Additional studies focused on vulnerable retreated areas (Caldara et al 1998(Caldara et al , 2012Mastronuzzi et al 2001Annese et al 2003;Milella et al 2008;Moretti et al 2016;Milli et al 2017;Van Loon et al 2017) by using classic surveys, innovative detection methodologies (Caldara et al 2012;Infante et al 2012;Mastronuzzi et al 2018) or marine geophysics and morphobathymetric investigations (Annese et al 2003;Mastronuzzi et al 2012;De Giosa et al 2019). Among these studies, a significant contribution about the characterisation of the Apulian coasts has been given by the research carried out on Alimini, Porto Cesareo, Torre Canne and Rosa Marina coasts (Falese et al 2016).…”

Investigation of rock mass deformation through nap-of-the-object photogrammetry: a case study of Hongyun Golden Peak in Fanjing Mountain, China

“…LiDAR has high recognition accuracy for flat-spreading hazards, such as landslides, debris flows, and ground collapse [20]. Further, 3D laser scanning, which can obtain information from the front or directly below the surface of an upright rock mass, has been utilized in hazardous rock zone investigations [21][22][23][24][25][26][27]. However, its accuracy is affected by the amount of vegetation cover and the site location.…”