LOCAL AND GENERAL MONITORING OF FORNI GLACIER (ITALIAN ALPS) USING MULTI-PLATFORM STRUCTURE-FROM-MOTION PHOTOGRAMMETRY

Experts from the University of Milan have been investigating Forni Glacier in the Italian alps for decades, resulting in the archive of a cumbersome mass of observed data. While the analysis of archive maps, medium resolution satellite images and DEM’s may provide an overview of the long-term processes, the application of close-range sensing techniques offers the unprecedented opportunity to operate a 4D reconstruction of the glacier geometry at both global and local levels. In the latest years the availability of high-resolution DEM's from stereo-photogrammetry (2007) and UAV-photogrammetry (2014 and 2016) has allowed an improved analysis of the glacier ice-mass balance within time. During summer 2016 a methodology to record the local disruption processes has been investigated. The presence of vertical and sub-vertical surfaces has motivated the use of Structure-from-Motion Photogrammetry from ground-based stations, which yielded results comparable to the ones achieved using a long-range terrestrial laser scanner. This technique may be assumed as benchmarking for accuracy assessment, but is more difficult to be operated in high-mountain areas. Nevertheless, the measurement of GCP’s for the terrestrial photogrammetric project has revealed to be a complex task, involving the need of a total station a GNSS. The effect of network geometry on the final output has also been investigated for SfM-Photogrammetry, considering the severe limitations implied in the Alpine environment.

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INTEGRATION OF TERRESTRIAL AND UAV PHOTOGRAMMETRY FOR THE ASSESSMENT OF COLLAPSE RISK IN ALPINE GLACIERS

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-3-w4-445-2018 ◽

2018 ◽

Vol XLII-3/W4 ◽

pp. 445-452 ◽

Cited By ~ 3

Author(s):

M. Scaioni ◽

L. Barazzetti ◽

M. Corti ◽

J. Crippa ◽

R. S. Azzoni ◽

...

Keyword(s):

Global Warming ◽

Structure From Motion ◽

3D Model ◽

Point Clouds ◽

Italian Alps ◽

Technical Aspects ◽

Alpine Glaciers ◽

Multi Temporal ◽

Glacier Ice

<p><strong>Abstract.</strong> The application of Structure-from-Motion photogrammetry with ground-based and UAV-based camera stations can be effectively exploited for modeling the topographic surface of Alpine glaciers. Multi-temporal repeated surveys may lead to geometric models that may be applied to analyze the glacier retreat under global warming conditions. Here the case study of Forni Glacier in the Italian Alps is presented. Thanks to the integration of point clouds obtained from the independent photogrammetric processing of ground-based and UAV blocks of images (captured on 2016), a complete 3D reconstruction also including vertical and sub-vertical surfaces has been achieved. This 3D model, compared to a second model obtained from a ground-based photogrammetric survey on September 2017, has been exploited to understand the precursory signal of a big collapse that might have involved tourists and hikers visiting the glacier ice tongue during summer. In addition to some technical aspects related to the acquisition and processing of photogrammetric data of glaciers, this paper highlights how Structure-from-Motion photogrammetry may help evaluate the risk of collapse in Alpine glaciers.</p>

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Microplastic Contamination in Snow from Western Italian Alps

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18020768 ◽

2021 ◽

Vol 18 (2) ◽

pp. 768

Author(s):

Marco Parolini ◽

Diego Antonioli ◽

Franco Borgogno ◽

Maria Cristina Gibellino ◽

Jacopo Fresta ◽

...

Keyword(s):

Polyethylene Terephthalate ◽

Human Activities ◽

High Mountain ◽

Low Density ◽

Italian Alps ◽

Mountain Areas ◽

Remote Areas ◽

Sampling Locations ◽

Local Sources ◽

The Mean

Recent studies have documented the presence of microplastics (MPs) in remote areas, including soils or sediments collected in mountain and glacier environments, but information on their presence in snow is scant. The present study aimed at exploring the presence of MPs in residual snow collected in four locations of the Aosta Valley (Western Italian Alps), with different accessibility and human presence. Overall, the µ-FTIR analyses confirmed the presence of 18 MPs in snow, 7 (39%) items were fibres, while 11 (61%) were fragments. Polyethylene (PE; 7 MPs) was the main polymer, followed by polyethylene terephthalate (PET; 3 MPs), high density PE (HDPE; 3 MPs), polyester (2 MPs), while only 1 MP made by low density PE, polypropylene and polyurethane were found. The mean (± SE) concentration of MPs in snow ranged between 0.39 ± 0.39 MPs/L and 4.91 ± 2.48 MPs/L, with a mean of 2.32 ± 0.96 MPs/L for the sampling locations. The concentration of MPs did not statistically differ among locations. Our results suggest that MPs presence in high-mountain ecosystems might depend on deposition through atmospheric precipitations or local sources due to human activities. For these reasons, policies aiming at reducing plastic use and dispersal in mountain areas may be effective in preventing local MP contamination.

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Diatom diversity in headwaters influenced by permafrost thawing: First evidence from the Central Italian Alps

Advances in Oceanography and Limnology ◽

10.4081/aiol.2018.7929 ◽

2018 ◽

Vol 9 (2) ◽

Cited By ~ 1

Author(s):

Federica Rotta ◽

Leonardo Cerasino ◽

Anna Occhipinti-Ambrogi ◽

Michela Rogora ◽

Roberto Seppi ◽

...

Keyword(s):

High Mountain ◽

European Alps ◽

Permafrost Degradation ◽

Mountain Areas ◽

Habitat Features ◽

Glacier Ice ◽

Water Ph ◽

Thawing Rate ◽

Permafrost Thawing ◽

Alpine Hydrology

Glacier melting and permafrost thawing are the most evident effects of the current climate change that is strongly affecting high mountain areas, including the European Alps. As the thawing rate of subsurface ice is lower than for glacier ice, it is expected that, while glaciers retreat, an increasing number of Alpine headwaters will become more influenced by permafrost degradation during the 21st century. Despite the expected change in the relative importance of glacier and permafrost in determining Alpine hydrology, studies addressing effects of permafrost thawing on chemical and, especially, biological features of adjacent surface waters are still scarce. The present study contributes to characterise the epilithic and epiphytic diatom diversity in a set of permafrost-fed headwaters in three sub-catchments differing in bedrock lithology of the Italian Central Alps (Trentino Alto-Adige) in relation to water chemistry and habitat features. In addition, it explores chemical and biological differences between permafrost-fed streams and headwaters with no direct contact to permafrost, namely glacier-fed (kryal) and precipitation-/groundwater-fed (rhithral) streams. Permafrost-fed waters showed higher electrical conductivity and enhanced ion concentrations than glacier- and precipitation-fed waters, while concentration of trace elements (e.g. Sr, Ni, Zn, As) were more irregularly distributed among waters of different origin, though they showed a tendency to reach higher levels in permafrost-fed waters. Diatom species richness and diversity were lower in permafrost-fed headwaters, and were principally related to water pH and trace metal concentrations. Epiphytic diatom assemblages were more diverse than epilithic ones, independently from the water origin, while differences in species composition were not sufficient to unequivocally identify a typical diatom composition for the different water types considered in this study.

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Rapid mapping accuracy assessment using low-cost UAV and open-source Structure from Motion

Rendiconti online della Società Geologica Italiana ◽

10.3301/rol.2020.19 ◽

2020 ◽

Vol 52 ◽

pp. 55-61

Author(s):

Ettore Potente ◽

Cosimo Cagnazzo ◽

Alessandro Deodati ◽

Giuseppe Mastronuzzi

Keyword(s):

Open Source ◽

Structure From Motion ◽

Accuracy Assessment ◽

Low Cost ◽

Mapping Accuracy ◽

Rapid Mapping ◽

Source Structure

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Formation Patterns of Mediterranean High-Mountain Water-Bodies in Sierra-Nevada, SE Spain

Water ◽

10.3390/w13040438 ◽

2021 ◽

Vol 13 (4) ◽

pp. 438

Author(s):

Jose Luis Diaz-Hernandez ◽

Antonio Jose Herrera-Martinez

Keyword(s):

Sierra Nevada ◽

Unknown Origin ◽

Slope Instability ◽

Water Bodies ◽

High Mountain ◽

Mountain Areas ◽

Glacial Processes ◽

The Mediterranean ◽

Water Volumes

At present, there is a lack of detailed understanding on how the factors converging on water variables from mountain areas modify the quantity and quality of their watercourses, which are features determining these areas’ hydrological contribution to downstream regions. In order to remedy this situation to some extent, we studied the water-bodies of the western sector of the Sierra Nevada massif (Spain). Since thaw is a necessary but not sufficient contributor to the formation of these fragile water-bodies, we carried out field visits to identify their number, size and spatial distribution as well as their different modelling processes. The best-defined water-bodies were the result of glacial processes, such as overdeepening and moraine dams. These water-bodies are the highest in the massif (2918 m mean altitude), the largest and the deepest, making up 72% of the total. Another group is formed by hillside instability phenomena, which are very dynamic and are related to a variety of processes. The resulting water-bodies are irregular and located at lower altitudes (2842 m mean altitude), representing 25% of the total. The third group is the smallest (3%), with one subgroup formed by anthropic causes and another formed from unknown origin. It has recently been found that the Mediterranean and Atlantic watersheds of this massif are somewhat paradoxical in behaviour, since, despite its higher xericity, the Mediterranean watershed generally has higher water contents than the Atlantic. The overall cause of these discrepancies between watersheds is not connected to their formation processes. However, we found that the classification of water volumes by the manners of formation of their water-bodies is not coherent with the associated green fringes because of the anomalous behaviour of the water-bodies formed by moraine dams. This discrepancy is largely due to the passive role of the water retained in this type of water-body as it depends on the characteristics of its hollows. The water-bodies of Sierra Nevada close to the peak line (2918 m mean altitude) are therefore highly dependent on the glacial processes that created the hollows in which they are located. Slope instability created water-bodies mainly located at lower altitudes (2842 m mean altitude), representing tectonic weak zones or accumulation of debris, which are influenced by intense slope dynamics. These water-bodies are therefore more fragile, and their existence is probably more short-lived than that of bodies created under glacial conditions.

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Structure-from-motion, multi-view stereo photogrammetry applied to line-scan sediment core images

Journal of Paleolimnology ◽

10.1007/s10933-021-00204-x ◽

2021 ◽

Author(s):

Kévin Jacq ◽

Estelle Ployon ◽

William Rapuc ◽

Claire Blanchet ◽

Cécile Pignol ◽

...

Keyword(s):

Sediment Core ◽

Structure From Motion ◽

Line Scan ◽

Stereo Photogrammetry

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Mapping the Distribution of Buried Glacier Ice – An Example From Lago Delle Locce, Monte Rosa, Italian Alps

Annals of Glaciology ◽

10.3189/s026030550000118x ◽

1986 ◽

Vol 8 ◽

pp. 78-81 ◽

Cited By ~ 4

Author(s):

W. Haeberli ◽

F. Epifani

Keyword(s):

Snow Cover ◽

Seismic Refraction ◽

Italian Alps ◽

Frozen Ground ◽

Near Surface ◽

Winter Snow ◽

Glacier Ice ◽

Geoelectrical Resistivity ◽

Monte Rosa

Techniques for mapping the distribution of buried glacier ice are discussed and the results, from a study carried out within the framework of flood protection work in the Italian Alps, are presented. Bottom temperatures of the winter snow cover (BTS) primarily indicate the heat flow conditions in the underlying ground and mainly depend on the presence or absence of an ice layer beneath the surface. Determination of BTS values is therefore an inexpensive method for quickly mapping the near-surface underground ice in areas where there is 1 m or more of winter snow cover. At greater depths, and/or when more detail is required, geoelectrical resistivity soundings and seismic refraction soundings are most commonly used to investigate underground ice. A combination of the two sounding techniques allows the vertical extent and the main characteristics (frozen ground, dead glacier ice) to be determined in at least a semi-quantitative way. Complications mainly arise from irregularity in the horizontal extension of the studied underground ice bodies, and they may have to be overcome by expensive core drillings and borehole measurements. Widespread occurrence of buried glacier ice was observed in morainic deposits, surrounding an ice-dammed lake near Macugnaga, Italy.

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Trapping of Organochlorine Compounds in High Mountain Lakes

The Scientific World JOURNAL ◽

10.1100/tsw.2001.320 ◽

2001 ◽

Vol 1 ◽

pp. 609-611 ◽

Cited By ~ 1

Author(s):

Joan O. Grimalt ◽

Pilar Fernandez ◽

Rosa M. Vilanova

Keyword(s):

Atmospheric Transport ◽

Mountain Lakes ◽

Organochlorine Compounds ◽

High Mountain ◽

High Latitudes ◽

High Mountain Lakes ◽

Mountain Areas ◽

Persistent Pollutants

High mountain areas have recently been observed to be polluted by organochlorine compounds (OC) despite their isolation. These persistent pollutants arrive at these remote regions through atmospheric transport. However, the mechanisms involving the accumulation of these compounds from the atmospheric pool to the lacustrine systems still need to be elucidated. These mechanisms must be related to the processes involving the transfer of these pollutant from low to high latitudes[1] as described in the global distillation effect[2].

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