Glaciers

The Glacier Inventory Geoportal is one of the products of the Territorial Knowledge System (SCT) of the Aosta Valley Region. It represents a web-based tool aimed at collecting and organizing on an informatic system the data and information about glaciers necessary for the government of the regional territory and planning activities on it.

The huge amount of data and information about the regional glacial systems kept in the Geoportal, as a cartographic section with an associated database (containing historical morphometric data and information), is the result of a continuous update over the years since 2003 byFondazione Montagna sicura - Montagne sûre.

The latest update was funded within the Interreg Italy-Switzerland 2014-2020 "RESERVAQUA" cross-border cooperation project and it mainly concerns the cartographic component of the Inventory which refers to the situation detected in 2019. This update is the product of the innovative use of high-resolution multispectral satellite images (maximum ground detail 10 m/pixel) acquired by the European Space Agency (ESA) within the Copernicus Program through the Sentinel-2 mission.

The older data instead were obtained from the analysis of historical iconographic documents (photos, prints, maps, etc.), from geomorphological evidence and clues imprinted in the forms of the landscape and from the very precious reports and archival documents kept by the Comitato Glaciologico Italiano (CGI). This catalog integrates, among the others, the dr. D.Bertolo and dr. F.Pollicino’s work carried out in the year 2000 on behalf of the Dipartimento del Territorio, dell’Ambiente e dei Lavori Pubblici of Aosta Valley Region. In detail, the perimeters of the glaciers referring to the years 1975, 1999, 2005 and 2012 were extracted from the digitization of orthophotos available (orthorectified images obtained from analog photographs) acquired during the various flights performed over the years on the regional territory.

CONSULTATION OF THE CARTOGRAPHIC GEOPORTAL

The cartographic section of the Inventory contains and presents the surfaces, the perimeters and the lengths of the actual and historical regional glacial systems.. The perimeters are represented graphically on cartography with a gradually darker color from the oldest to the most recent: there are data for the entire regional territory for the years 1820, 1975, 1999, 2005, 2012 and 2019; while only for some glaciers there are cartographic information referable to other years.

It is possible to select the year of interest to view the maximum extension of the glacier using the "Storicità" option, in the menu on the left of the screen. The extinct glaciers are represented with a gray snowflake icon.

The database associated with the cartographic section contains numerous data and information for each single glacier presented into consultation forms referring to the different years. It is possible to access to the forms in two ways:

  • through the cartographic section of the Geoportal, by clicking directly on the maptip (graphically represented by a snowflake icon) located in the center of gravity of the glacier of interest;
  • selecting the "Data search" option in the menu of the Homepage of the website..

Information is organized by year and they mainly concern of morphometric data (areas, lengths, widths, elevations) according to the standards set by the World Glacier Inventory (WGI), in particular:

  • the surface of the glacier (km2) is calculated planimetrically;
  • the length of the glacier refers to the line that virtually unites the maximum and minimum altitude reached along the flow line downstream of the glacier;
  • la larghezza è definita come la lunghezza della curva di livello “più lunga” che attraversa il ghiacciaio.

the width is defined as the length of the “longest” line that crosses the glacier.

Rare and precious images (photos, prints, etc.) and historical cartographic excerpts are also available for some particular years.

From the Inventory, therefore, numerous and precious historical data and information on the characteristics and evolution of the Aosta Valley regional glacialism can be obtained. Some data on the most recent evolution:

  • in 1975 the glaciers registered were 297 with a total surface area of approx. 188 km2;
  • in 1999 the number of glaciers had dropped to 216 with an area reduced to about 154 km2;
  • the 2005 census counted 209 glaciers spread over an area of approx. 135 km2;
  • in 2012 the number of glaciers was further reduced to 184 on a total surface of approx. 127 km2;
  • in 2019 the number of glaciers remained unchanged compared to 2012, despite a further reduction in the total area, equal to approx. 120 km2;