Data for Slovenia

Objectives summarized by: Resolution on National Environmental Action Programme 2005-2012 (ReNPVO, Official Gazette of the RS, No. 2/06).
Source database or source: Anton Melik Geographical Institute at the Science and Research Centre of the Slovenian Academy of Sciences and Arts, the data was obtained by geodetical measurements and photogrammetric survey.
Data administrator: Anton Melik Geographical Institute at the Science and Research Centre of the Slovenian Academy of Sciences and Arts
Data acquisition date for this indicator: 10 September 2009
Methodology and frequency of data collection for the indicator: The data is presented for the 1992-2008 period.
Data processing methodology: Measurements are carried out every year at the end of the melting period – the end of August or September. Classical geodetic measurements are taken through theodolite and/or photogrammetric survey.
Information concerning data quality:
- Advantages and disadvantages of the indicator: The data is comparable with the database of the World Glacier Monitoring Service based in Zürich.
- Relevance, accuracy, robustness, uncertainty: In years when the glacier is covered by snow at the end of the melting period, it is not possible to measure the extent of ice, but only of snow, which is why the glacier's extent and volume are overrated in those years. Due to weather conditions, measurements cannot be performed each year on the same day at the end of the melting period, so the extent of the glacier is not lowest on the same day each year.
Reliability of the indicator (archive data): The data is not published in any publicly available databases, but in various scientific and expert articles.
Uncertainty of the indicator (scenarios/projections): No scenarios, projections available
-Overall estimate (1 = no major remarks, 3 = data with reservation):
Relevance: 1
Accuracy: 1
Completeness over time:1
Completeness over space: 1

Ever since 1946, the Anton Melik Geographical Institute at the Science and Research Centre of the Slovenian Academy of Sciences and Arts conducts regular annual measurements of the Triglav and Skuta glaciers.

In 1946, measuring points were set up around the Triglav glacier from which the distance to the glacier was measured with measuring tape. On the basis of these measures, glacier drawings were made by individual year as along with assessments of the glacier's surface area. With the glacier retreating, several measuring points became too remote, and subsequent years saw the establishment of new ones. Given that the locations of all measuring points are geodetically measured, it has been possible all these years to make fairly accurate calculations of the glacier's surface area. Along with performing measurements, the expert team of the Anton Melik Geographical Institute also took regular photographs of the glacier from Begunjski vrh. Moreover, these photographs serve as an excellent source for the reconstruction of the glacier's extent throughout the past decades. Since 1976, there has also been a regular monthly photographing of the glacier from two fixed locations on Kredarica. As a rule, regular annual measurements are performed in mid-September, at the end of the melting period. In some years, however, measurements were rendered impossible by early snowfall.

In 1952, 1995 and 1999, the glacier was also measured geodetically. Since 1999, an airborne photogrammetric survey has been organised every second year. This photographic material has facilitated the calculations of changes in the glacier’s surface area and volume between individual years. In 2005, an airborne photogrammetric survey was organised, whereas in 2007 and 2008 terrestrial photogrammetric surveys were carried out.

In 1999 and 2001, geo-radar measurements were carried out for the provision of data on ice layer thickness by individual cross-section.
To calculate a glacier’s volume, we need information on its surface and its rocky base. Data on surface by individual year was obtained on the basis of photogrammetric survey in individual years, while the data on the rocky base was obtained from geo-radar measurements that were carried out in 2001. However, the data on the glacier’s rocky base in particular may be problematic or not precise enough due to its karstic diversity. Data on glacier volume is therefore only an estimation.

The World Glacier Monitoring Service based in Zurich collects data on glacier oscillations. In several glaciers, the series of data dates as far back as 1894.