Download - GLIMS: Global Land Ice Measurements from Space

3.3. THE AUSTRIAN GLACIER INVENTORY 27Zone Central Meridian Scale False Easting False NorthingM28 10 ◦ 20' 1 150 000m -5 000 000mTable 3.5: Specications for TM zone M283.3 The Austrian Glacier InventoryAustrian glaciers have been monitored since the early 19 th century. The rst inventorywas compiled by E. Richter in 1888. With the fth regional recording theglacier data became more accurate. Groÿ (Groÿ, 1987) mapped the ice covered areaof 1850 (1011 km 2 ), 1920 (808 km 2 ) and 1969 (542 km 2 ) within the present Austrianborders. For the Stubaital the glaciered area in 1969 was 6077 ha.The Austrian Glacier Inventory of 1969 was based on a special aerial photogrammetricsurvey. For some small glaciers the analysis had to be done using topographicmaps in the scale of 1:25.000 and 1:50.000. The aerial photographs have a resolutionof about 0.5 m. The photographs and contour maps have been analysed usingphotogrammetric and cartographic methods in a scale of 1:30.000.The resulting maps contain glacier boundaries, snow lines, moraines, isolines andspot heights in a scale of 1:10.000 to 1:50.000. The height accuracy is about 1m (seeEder et al., 2000).The new Austrian Glacier Inventory of 1997, based on aerial photographic surveysfrom 1996 to 1998 is still being processed. The image scale varies from 1:15.000to 1:35.000. The aerial photographs have been digitised with a resolution of 15µand 30µ using the photogrammetric precision scanner PS1 (Zeiss). Based on theseimages digital elevation models were produced using a semi-automatic photogrammetricmethod with a height accuracy of 1m (summary of comments by AstridLambrecht).All glaciers of the inventory as well as moraines and lakes have been manually delineated.The Austrian Glacier Inventory of 1969 has been digitised. For some parts of theinventory (e.g. Ötztal) the available maps could also be digitised. For some glaciersthe aerial photographs had been analysed again. The analysis for the new inventoryis carried out using GIS technology. Output from the production process includesthe minimum, maximum and mean elevation of the glaciers, the total area, the areaof the glaciers for individual elevation bands and also the dierence between the twoglacier surfaces from 1969 and 1997.Figure 3.2 shows the aerial photograph of the new Austrian Glacier Inventory for