Comments by Wilfried Haeberli

General:

The authors present a geo-historical study about events which prompted risk management actions in the European Alps. This is an interesting, important but also serious, complex and difficult topic, the treatment of which requires rich international knowledge and practical experience. The submitted text only partially fulfils such expectations. It is quite heavily biased concerning its sources (many French sources, websites, references of limited scientific value) and lacks fundamentally important policy-related developments in Switzerland with their influence on the evolution of international climate-related concepts for integrative and future-oriented high-mountain hazard assessments and risk management under conditions of ongoing climate change (GAPHAZ).

The following comments concerning such Swiss developments may help the authors to describe the existing information in a more adequate, equilibrated and critically reflected way. This unavoidably involves references to my own work and to the work of my close colleagues (sorry). The corresponding references are given here to provide the authors access to important sources of information. The Cambridge UP book “The High-Mountain Cryosphere – Environmental Changes and Human Risks” (Huggel et al. 2015) together with the Elsevier book on “Snow and Ice-Related Hazards, Risks, and Disasters” (Haeberli and Whiteman 2021) contain rich information and numerous references. It would be adequate to cite these international key publications.

The 1965 Mattmark ice avalanche catastrophe marks a decisive turning point concerning the recognition and treatment of glacier hazards in Switzerland. The Swiss Federal Department of the Interior established a working group on glacier hazards (“Arbeitsgruppe für gefährliche Gletscher”), which collected information on past events to derive practice-oriented rules and empirical approaches to recognize and assess glacier hazards (Haeberli 1983, Alean 1985, Haeberli et al. 1985). Huggel et al. (2004) later published an updated version for practice-oriented hazard assessments in view of possible international discussion and application. The completion of this systematic practice-oriented scientific work specially created a basis for overcoming the before primarily used “dogma” of “unforeseeable natural events” as used (under political pressure) in the Mattmark court case to acquit the responsible engineers – a judgement today quite generally considered to have been a miscarriage of justice (Marti 2025).

In a special investigation initiated by the Swiss National Parliament, the analysis of the 1987 flood catastrophes comprised a systematic analysis of about 600 primarily high-altitude debris flows in view of technical recommendations for future hazard assessment and protection work (Rickenmann and Zimmermann 1993). The large number of glacial and periglacial source areas had made clear that environmental conditions were changing beyond historical-empirical precedence and that comprehensive assessments of continued system changes had to be applied. This was in contrast to the narrow-linear and retrospective consideration of past glacier events only as later applied with the “Inventar gefährlicher Gletscher” (inventory of dangerous glaciers) at VAW/ETHZ and the EU-project GLACIORISK using similar narrow and retrospective approaches.

Three Swiss National Research Programmes (NRPs) – established by the Swiss National Parliament in view of policy-related knowledge development – contained specific projects about cold-mountain hazards in view of improved, future-oriented approaches to be applied by responsible authorities: Within NRP 31 on Climate Change and Natural Catastrophes, the project “Eisschwund und Naturkatastrophen im Hochgebirge” (ice vanishing and natural catastrophes in high mountains; Haeberli et al. 1999) established the connexion with climate change and its effect on cold-mountain hazards/risks, including transdisciplinary case studies on flood protection from periglacial lakes at Gruben (Haeberli et al. 2001), debris flows from creeping permafrost at Pontresina (both with heavy construction work carried out on behalf of federal, cantonal and municipal authorities) and stability aspects of a polythermal hanging glacier on permafrost of the Eiger W-face. NRP 48 on Landscapes and Habitats of the Alps contained the project GISALP with a focus on spatiotemporal information as a planning tool concerning rapid changes of high-Alpine environments under the effects of climate change (Haeberli et al. 2007). NRP 61 with its project NELAK on new lakes forming because of glacier retreat and related chances and risks paved the way for comprehensive, future-oriented hazard and risk assessments (Haeberli et al. 2013).

The EU-funded PACE-project on permafrost and climate in Europe (Harris et al. 2009, Etzelmüller et al. 2020) for the first time produced a comprehensive scientific knowledge basis about permafrost in the Alps and its long-term changes under global change, including deep boreholes for long-term permafrost monitoring and recommendations for hazard anticipation. This together with the previous works on lake outbursts, ice avalanches and debris flows now formed the basis for international guidelines related to comprehensive/integrative, future-oriented assessments of glacier and permafrost-related hazard in warming-up cold mountain regions (GAPHAZ and Allen et al. 2022 as cited in the text). The application of high-tech remote sensing technologies today has become standard (cf. early Swiss work by Huggel et al. 2002 and Kääb et al. 2005).

Technical remarks:

Some more technical remarks can be found in the annotated text file. The reference list must be carefully controlled and in places completed (several citations in the text are not in the reference list, bibliographic information is missing or incomplete in several cases, not all weblinks seem to be working).

References:

Etzelmüller, B., Guglielmin, M., Hauck, C., Hilbich, C., Hoelzle, M., Isaksen, K., Noetzli, J., Oliva, M., and Ramos, M. (2020):Twenty years of European mountain permafrost dynamics – the PACE legacy, Environmental Research Letters 15, 104070. doi:10.1088/1748-9326/abae9d

Haeberli, W. (1983): Frequency and characteristics of glacier floods in the Swiss Alps. Annals of Glaciology, 4, 85-90.

Haeberli, W. and Whiteman, C. (2021): Snow and Ice-Related Hazards, Risks, and Disasters. Elsevier, Amsterdam. ISBN 978-0-12-817129-5

Haeberli, W., Alean, J.C., Müller, P. and Funk, M. (1989): Assessing risks from glacier hazards in high mountain regions: some experiences in the Swiss Alps. Annals of Glaciology 13, 96-102.

Haeberli, W., Bütler, M., Huggel, C., Müller, H. & Schleiss, A. (2013): NELAK – Neue Seen als Folge des Gletscherschwundes im Hochgebirge – Chancen und Risiken. Forschungsbericht NFP 61. Zürich, vdf Hochschulverlag AG an der ETH Zürich, 300p.

Haeberli, W., Kääb, A., Hoelzle, M., Bösch, H., Funk, M., Vonder Mühll, D. und Keller, F. (1999): Eisschwund und Naturkatastrophen im Hochgebirge. Schlussbericht NFP 31, v/d/f Hochschulverlag ETH Zürich.

Haeberli, W., Kääb, A., Vonder Mühll, D. and Teysseire, Ph. (2001): Prevention of outburst floods from periglacial lakes at Grubengletscher, Valais, Swiss Alps. Journal of Glaciology, 47/156, 111-122.

Haeberli, W., Keller, F., Krüsi, B., Egli, M., Rothenbühler, C., Meilwes, J. und Gruber, S. (2007): GISALP – raum-zeitliche Information über schnelle Klimaänderungen in hochalpinen Umweltsystemen als strategisches Werkzeug für Analyse, Kommunikation, partizipative Planung und Management im Tourismusgebiet Oberengadin. Forschungsbericht NFP 48, Schweizerischer Nationalfonds, vdf Hochschulverlag ETH Zürich, 213p.

Harris, C., Arenson, L.U., Christiansen, H.H., Etzelmüller, B., Frauenfelder, R., Gruber, S., Haeberli, W., Hauck, C., Hoelzle, M., Humlum, O., Isaksen, K., Kääb, A., Kern-Lütschg. M.A., Lehning, M., Matsuoka, N., Murton, J.B., Nötzli, J., Phillips, M., Ross, N., Seppälä, M., Springman, S.M. and Vonder Mühll, D. (2009): Permafrost and climate in Europe: Monitoring and modelling thermal, geomorphological and geotechnical responses. Earth-Science Reviews 92, 117-171.

Huggel, C., Carey, M., Clague, J.J. and Kääb, A. (2015): The High-Mountain Cryosphere – Environmental Changes and Human Risks. Cambridge University Press. ISBN 978-1-107-06584-0

Huggel, C., Haeberli, W., Kääb, A., Bieri, D. and Richardson, S. (2004): An assessment procedure for glacial hazards in the Swiss Alps. Canadian Geotechnical Journal 41, 1068-1083.

Kääb, A., Huggel, C., Fischer, L., Guex, S., Paul, F., Roer, I., Salzmann, N., Schlaefli, S., Schmutz, K., Schneider, D., Strozzi, T. and Weidmann, Y. (2005): Remote sensing of glacier- and permafrost-related hazards in high mountains: an overview. Natural Hazards and Earth System Sciences 5, 527–554.

Marti, K. (2025): Der steinige Weg vom Freispruch zum Fehlurteil. In: Joris, E., Hg. Mattmark 1965 – Erinnerungen, Gerichtsurteile, Italienisch-Schweizerische Verflechtungen. Rotpunktverlag. ISBN 978-03973-072-8

Rickenmann, D. and Zimmermann, M. (1993): The 1987 debris flows in Switzerland: Documentation and analysis. Geomorphology 8, 175–189.

General comments

Bazin et al. present a study on how glacial and periglacial hazards were managed in the Alps during the last ca. 200 years, drawing on multiple case studies and a database which has been developed earlier.

In principle, I welcome this effort as it has the potential to generate new insights across different environmental, societal and political contexts and countries, and across quite a large time period. I also think this paper could fill a gap because these hazard and risk management practices and associated contexts have not been widely studied.

As it stands currently, however, the paper cannot fulfill these expectations, and I think substantial efforts are necessary to bring it more closely to publication.

Although quite a considerable database is used and further developed (based on an earlier one), much of the paper is rather fueled by anecdotal evidence from a number of cases, and the insights remain somewhat superficial, and it is not so clear what has now really been gained by the efforts undertaken.

Together with the language (which really needs improvement, many typo’s, unfinished sentences, etc) and the figures and references, it gives the impression that this paper has not yet reached maturity.

A few more specific points:

In sections 1 and 2 the technical language and wording is often not precise enough. For instance (line 50) permafrost degradation and glacial debuttressing typically do not trigger rock fall and avalanches but are contributing factors.

Or line 79, exposure should be added to the risk equation.

Line 82, mountain valleys are considered vulnerable because of their exposure to hazards: this needs to be worded more precisely and adequately.

For section 2 I generally think that this conceptual part should be deepened, and wording be more precise. I suggest to look further into the literature, e.g. also into IPCC AR6 about terms, definition and concepts, and literature therein.

Line 125: I’m wondering whether it is reasonable to also focus on the geophysical processes of the mass movements of the events? I would rather suggest not to do so, and instead deepen the core topic of the paper.

Line 142: say that you mean volume of the events.

Section 3.2.1: overall I think that the 7 pillars represent a comprehensive set of action for risk and crisis management. Internationally, more common are risk management cycles, and the authors may consider this classification as well (or at least make reference to it), which includes response, recovery, prevention and preparedness. The response part seems to be missing from the 7 pillars.

Lines 536 – 552: I think this is a really interesting part, i.e. to see how management of glacial and periglacial risks has changed over time. However, the current text can only superficially touch on it, missing substance. This could be a topic where the authors want to invest more time to deepen it and provide then an analysis with more insights.

Line 563: the distinction between proactive and reactive management is ok but the paper should also cover other concepts, and how they fit in, specifically in relation to the integrative risk management cycle.

Line 614ff. I don’t quite understand here the concept of feedback in this context. If the authors think it is relevant, then I suggest they further elaborate on it.

Lines 669-682: I suggest that the authors also make reference to the era of satellite imagery which has facilitated documentation of events that would otherwise have gone unnoticed or hardly documented (e.g. several ice and rock-ice avalanches in remote areas of Asia).

Figures

The figures are really not in a quality that would be any close to be ready for publication, and this concerns virtually all figures. Readability is not ensured in the maps, and the bar plot figures could be enhanced. I think the authors would need to invest a more serious amount of time here.

Please carefully check the references (e.g. Ancey 2017 is missing in the reference list).

I suggest you also consider Niggli et al. 2024 for risk management around GLOFs:

Niggli, L., Allen, S., Frey, H., Huggel, C., Petrakov, D., Raimbekova, Z., Reynolds, J., Wang, W., 2024. GLOF Risk Management Experiences and Options: A Global Overview, in: Oxford Research Encyclopedia of Natural Hazard Science. https://doi.org/10.1093/acrefore/9780199389407.013.540

The other review (by Wilfried Haeberli) has already indicated a number of important sources that should be considered, so I won’t repeat nor expand on it here.

Conclusions:

I like the topic of the paper and think it is highly relevant, and there is also a gap in the current scientific literature, so definitely a window of opportunity for such a paper. But I’m afraid that the authors will need a very substantial effort to get the paper ready for publication. I hope they can address the challenge.

Christian Huggel, University of Zurich

The paper presented by the authors develops a study on the historical development of the management of glacial and periglacial hazards in the Alpine region. The topic is relevant in the actual evolution of cryospheric hazards in the Alps and a comparison between different management strategies that have been implemented in the past and that are actually being developed nowadays is an interesting field of research. Moreover, literature seem to lack specific studies on this topic. Because of this, the development of this work may be particularly challenging, but it’s a good chance to fill a gap in this field of research.

The main specific issues in the paper, in my point of view, could be summarized as follows:

1) The compilation of the database of events used to analyse the management responses has some specific issues:

a) The methodology used to compile the database is not precisely highlighted; it is not clear if all types of data were used in all the Alpine countries (See the example of the avalanche databases in the specific comments in the attachment).

b) Probably a consequence of the methodological approach issues exposed above, biases can be individuated towards specific regions where more detailed information has been accessed.

2) Analysis of the obtained data could be more detailed and be better exposed in the paper; this could also trigger more insights in the discussion. Moreover, the database should be made freely accessible.

3) Writing could be improved.

4) Figures quality could be improved.

5) Bibliographic references should be implemented.

I addressed specific comments in the attached PDF.

I think that a lot of the comments in my review, together with the detailed reviews of the other referees give the authors a good array of resources on which they can build up a considerable improvement of the actual manuscript.

I believe that the publication of an improved version of this work will be highly appreciated by the scientific community interested in this field of study so I encourage the authors to take the time to take into account all the comment from the referees.