Future glacial lakes in the Swiss Alps

Due to the retreat of the glaciers, new lakes are formed in depressions released by the ice. These lakes can be a hazard during their formation. Later, large lakes can be interesting for electricity production. The new lakes cannot visually replace the missing glaciers, but they certainly enhance the remaining landscape.

A team consisting of scientists from the ETH Zurich, the WSL and the University of Fribourg has determined in a research project where the formation of new lakes in the Swiss Alps is to be expected. With the help of radar-measured ice thickness and a terrain model, the position, volume, greatest depth, average depth, contours, time of formation and much more were determined in a certainly non-trivial simulation. According to this work, the formation of around 600 glacial lakes can/must be expected in the coming decades.

The results of this work were published in March 2022 in a scientific publication. The data are in a format that can only be opened and viewed with a GIS (= Geographic Information System). This is a pity, as not all interested people are likely to have direct access to a GIS.

That is why we at SwissGlaciers.org are trying to make the results of the research work accessible to a wider audience by simple means. A small, self-developed programme converts the coordinates and puts the data into a form in which they can be displayed on the Swiss national maps (map.admin.ch), for example.

In a first step the position of the future glacial lakes can be viewed on map.admin.ch (= Official National Maps of Switzerland). For each lake, a do or outline is displayed on the map:
- Red dot/outline (683 Stk.): Lake with area >= 5000m2 and maximum depth >= 5m.
- Green dot/outline (1322 Stk.): All other lakes with maximum depth >= 1m.

After clicking on one of these red dots, the following data is displayed in a small window:
. - aera: Area of the lake in square kilometres
- volume: Volume of the lake in million cubic metres
- max_depth: Maximum depth of the lake in metres
- avg_depth: Mean depth of the lake in metres

The national maps, including future glacier lakes, can be accessed directly for the glaciers we document. The link is located far down on the relevant pages. This is in the chapter 'Further information'.
Example: Rhone glacier
The link is also displayed if no new lakes are created at the glacier in question according to the simulation.

Regarding the smaller lakes (including green dots/outlines in map), the authors of the study write: Smaller lakes are not considered interpretable because of uncertainties in the topography of the underlying glacial bed
. The smaller lakes (= green dots/outlines) are shown in the map because we encountered a few of these small, newly formed lakes in the field.

We observe and document the formation of future glacial lakes on the following glaciers:

We received support as follows:
- The research team gave us the OK to use the data.
- The helpdesk Geoportal des Bundes (geo.amdin.ch) showed us how to call map.admin.ch so that the processed data is displayed directly.
. Many thanks for the support!