Evaporite sinkholes of the Friuli Venezia Giulia region (NE Italy)

Abstract

Sinkholes are common in the Friuli Venezia Giulia (FVG) Region (NE Italy), where the presence of karstifiable rocks favours their occurrence accelerated by intense rainfalls. Their existence has been reported since the end of the 1800s along the Tagliamento Valley, in correspondence with the mantled evaporites (gypsum). Furthermore, tens of evaporite sinkholes have been documented on the reliefs adjacent to the village of Sauris and along the narrow W-Eoriented valleys, where regional faults have played a major role in their spatial distribution. This paper reports for the first time an inventory of the sinkholes affecting the evaporites of the FVG Region. These phenomena were mapped and categorised using a genetic classification. The main output is an A0-format map, which incorporates a 1:50,000 scale Sinkhole Inventory Map (SIM). The SIM encompasses 552 sinkholes. The cover suffosion sinkholes are the most abundant, followed by bedrock collapses. There is a clear prevalence of the circular shape (65%) over other shapes. Diameters are 1-140 m, with depths ranging 0.1-40 m with a mean value of 4.5 m. The SIM can motivate regional planning authorities to perform further investigations aimed to understand the geomorphological evolutions of these phenomena. ARTICLE HISTORY

Evaporite Dissolution Rate through an on-site Experiment into Piezometric Tubes Applied to the Real Case-Study of Quinis (NE Italy)

“…In the area, the genesis and evolution of sinkholes is strongly guided by geological and structural features [49]. Indeed, the Tagliamento River valley, is conditioned by a series of tectonic lineaments having a regional character with a prevailing E-W direction related to the Alpine tectonics.…”

“…The most part of them have no more morphological evidence, and some of them represent recurrent phenomena, which, sometimes, are in turn refilled by local farmers (an example is given by the sinkhole in Figure 1c). The diameter of the sinkhole's population ranges between 1 m and 45 m, with an average value of 8 m. The depth ranges from 0.5 m up to 15 m (average value of 2.4 m [49]).…”

Geometry and paleo-ice content of rock glaciers in the southeastern Alps (NE Italy – NW Slovenia)

“…Moreover, the same areas of both countries have been recently surveyed by several authors and with different purposes, in order to map and rise knowledge about the coastal areas (Biolchi, Furlani, Covelli, Busetti, & Cucchi, 2016), the Classical Karst region (Jurkovšek et al, 2016), the hydrogeological functioning of the alluvial plain (Treu et al, 2017) as well as the sinkhole occurrence and analysis (Calligaris, Devoto, & Zini, 2017). Glacial features and morphologies were already mapped by Colucci and Žebre (2016) and Žebre and Stepišnik (2016), therefore this work is part of an extensive effort aiming for a better understanding of environments and landscapes of this transboundary European area.…”

Integration of multi-criteria and nearest neighbour analysis with kernel density functions for improving sinkhole susceptibility models: the case study of Enemonzo (NE Italy)

“…Within the framework of several different projects funded by the Regional Geological Survey of the FVG region as well as by the Enemonzo municipality the researchers of the Mathematics and Geosciences Department of Trieste University realised the first sinkhole inventory of the study area (Calligaris et al, 2017b) (Fig. 3A).…”

“…For the field survey analyses, the study was realized at a 1:5,000 scale (Calligaris et al, 2017b). The elevation and the products derived from the Digital Elevation Model have a cell size of 1 m.…”