Aerial and UAV Images for Photogrammetric Analysis of Belvedere Glacier Evolution in the Period 1977–2019

Abstract

Alpine glaciers are strongly suffering the consequences of the temperature rising and monitoring them over long periods is of particular interest for climate change tracking. A wide range of techniques can be successfully applied to survey and monitor glaciers with different spatial and temporal resolutions. However, going back in time to retrace the evolution of a glacier is still a challenging task. Historical aerial images, e.g., those acquired for regional cartographic purposes, are extremely valuable resources for studying the evolution and movement of a glacier in the past. This work analyzed the evolution of the Belvedere Glacier by means of structure from motion techniques applied to digitalized historical aerial images combined with more recent digital surveys, either from aerial platforms or UAVs. This allowed the monitoring of an Alpine glacier with high resolution and geometrical accuracy over a long span of time, covering the period 1977-2019. In this context, digital surface models of the area at different epochs were computed and jointly analyzed, retrieving the morphological dynamics of the Belvedere Glacier. The integration of datasets dating back to earlier times with those referring to surveys carried out with more modern technologies exploits at its full potential the information that at first glance could be thought obsolete, proving how historical photogrammetric datasets are a remarkable heritage for glaciological studies.

Giving Historical Photographs a New Perspective: Introducing Camera Orientation Parameters as New Metadata in a Large-Scale 4D Application

“…An exhaustive overview of the origins, available via online portals, and the present challenges are given in [5]. Georeferenced historical (aerial) images can be, e.g., used for the change detection of glaciers [6,7] or buildings [8], landslide investigation [9], or even the detection of unexploded ordnance [10].…”

Icepy4d: A Python Toolkit for Advanced Multi-Epoch Glacier Monitoring With Deep-Learning Photogrammetry

“…The northern lobe of the Belvedere Glacier was chosen as the test site for ICEpy4D as part of an ongoing long-term monitoring project (Ioli et al, 2023b). Historical aerial images were used for photogrammetric modeling from 1977 to 2001 (De Gaetani et al, 2021), and since 2015, yearly in-situ UAV and GNSS surveys have been conducted to monitor glacier evolution (Ioli et al, 2021).…”

Mid-Term Monitoring of Glacier’s Variations with UAVs: The Example of the Belvedere Glacier

“…Recently, ref. [43] used historical aerial images and UAVs to photogrammetrically reconstruct glacier volume variations between 1977 and 2019. For the period 1977-1991, they confirmed the glacier expansion, with a volume increase of +10.06 × 10 6 m 3 (+0.72 × 10 6 m 3 y −1 ).…”

“…For the time-span 2009-2019, ref. [43] derived a negative variation of −27.16 × 10 6 m 3 of ice (−2.72 × 10 6 m 3 y −1 ). This last ten-years-averaged estimate well matches with the annual volume variations found in this study between 2015 and 2020 (between −2 × 10 6 m 3 y −1 and −3.5 × 10 6 m 3 y −1 ).…”

“…Moreover, over the past century, the Belvedere Glacier experienced extraordinary dynamics, such as a surge-type movement or the formation of a supra-glacial lake, which seriously threatened the nearby municipality of Macugnaga [10,38]. Due to its particular relevance, the Belvedere Glacier has been widely studied for decades [6,18,[37][38][39][40][41][42][43] and it is still object of monitoring by local authorities. Nevertheless, at the best of authors knowledge, there are no recent works aimed at continuously monitor the glacier dynamics for a period of several years with a high geometrical resolution and accuracy.…”