Historical glacier outlines from digitized topographic maps of the Swiss Alps for the years ca. 1900 and ca. 1935

Abstract: Since the end of the Little Ice Age around 1850, the total glacier area of the Central European Alps has considerably decreased. In order to understand the changes in glacier coverage at various scales and to model past and future streamflow accurately, long-term and large-scale datasets of glacier outlines are needed. To fill the gap between the morphologically reconstructed glacier outlines from the moraine extent corresponding to the time period around 1850 and the first complete dataset of glacier areas in the Swiss Alps from aerial photographs in 1973, glacier area from 80 sheets of a historical topographic map (the Siegfried map) were manually digitized for the publication years 1878-1918 (further called first period, with most sheets being published around 1900) and 1917-1944 (further called second period, with most sheets being published around 1935). The accuracy of the digitized glacier areas was then assessed through a two-step validation process: the data were (1) visually and (2) quantitatively compared to glacier area datasets of the years 1850, 1973, 2003, and 2010, which were derived from different sources, at the large-scale, basin-scale and locally. The validation showed that at least 70 % of the digitized glaciers were comparable to the outlines from the other datasets and were therefore plausible. Furthermore, the inaccuracy of the manual digitization was found less than 5 %. The presented datasets of glacier outlines for the first and second periods are a valuable source of information for long-term glacier mass balance or hydrological modelling in glacierized basins. The uncertainty of the historical topographic maps should be considered during the interpretation of the results
Umfang und Inhalt: The datasets contain the digitized glacier outlines for the years around 1900 and 1935. For both digitized periods, two shape files are available. The first shape file contains the glacier areas delineated from the digitized sheets of the historical topographic map themselves with the name of the sheet as identification and the year of publication. The sheets that are exactly identical for both periods are identified in a comment field in the shape file (in total 28 from 80 sheets). The second shape file contains the individual digitized glaciers for the first digitized period (in total 957) and the second digitized period (in total 948) with unique identification number. As some glacier extents overlap several sheets and might therefore contain several publication years, the information of both shape files cannot be resumed in a single file. The basin outlines used for glacier delineation are also available in a separate shape file. All shape files were produced in the CH1903_LV03 projection system. Please note that the given years is the publication year and not the survey year. The Survey might have occured up to few years before publication. A readme pdf-file provides a detailed data description

Angaben zum Objekt

• Standort: Deutsche Nationalbibliothek Frankfurt am Main
• Umfang: Online-Ressource
• Ausgabe: 2., korrigierte Version
• Sprache: Englisch

Klassifikation und Themen

• Klassifikation: Geografie, Reisen (Deutschland)
• Schlagwort: Gletscherkunde

Beteiligte, Orts- und Zeitangaben

• Ereignis: Veröffentlichung
• (wo): Freiburg
• (wer): Universität
• (wann): 2018
• Urheber: Mennekes, David ; Seibert, Jan ; Weiler, Markus
• Beteiligte Personen und Organisationen: Freudiger, Daphné ; Albert-Ludwigs-Universität Freiburg. Professur für Hydrologie, 2013- ; Universität Zürich ; Albert-Ludwigs-Universität Freiburg. Fakultät für Umwelt und Natürliche Ressourcen

Weitere Informationen

• DOI: 10.6094/UNIFR/15008
• URN: urn:nbn:de:bsz:25-freidok-150087
• Rechteinformation: Kein Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Letzte Aktualisierung: 25.03.2025, 13:55 MEZ