Assessment of Glacier and Permafrost Hazards in Mountain Regions: Technical Guidance Document

Submitted by Julia Barrott | published 9th Aug 2022 | last updated 12th Oct 2022
Oblique view of the GLOF hazard map for the Chucchún catchment and the city of Carhuaz, Cordillera Blanca, Peru (cf. Schneider et al. 2014). Background: GoogleEarthTM.

Oblique view of the GLOF hazard map for the Chucchún catchment and the city of Carhuaz, Cordillera Blanca, Peru (cf. Schneider et al. 2014). Background: GoogleEarthTM.

Introduction

Hazards relating to glaciers and permafrost occur in most mountain regions of the world and are a threat to lives, livelihoods, and sustainable development within some of the world’s most vulnerable communities. In view of rapid global warming and related changes in the sensitive mountain cryosphere, landscapes are evolving and new threats are emerging. Coupled with the ongoing expansion of people and their infrastructure into high mountain valleys there is an increasing potential for societal losses and far-reaching disasters.

Recognising the need for a structured and comprehensive approach to hazard assessment underpinned by latest scientific understanding, the Joint Standing Group on Glacier and Permafrost Hazards in High Mountains (GAPHAZ) of the International Association of Cryospheric Sciences (IACS) and the International Permafrost Association (IPA) has produced this technical guidance document* as a resource for international and national agencies, responsible authorities and private companies. The work has been substantially supported by the Swiss Agency for Development and Cooperation (SDC) through the Glaciares+ Project.

In the context of a warming and evolving mountain landscape, this technical guidance document focusses on hazards that are directly conditioned or triggered by contemporary changes in mountain glaciers and permafrost. Emphasis is given to catastrophic mass flows that can travel far downstream or downslope, potentially leading to cascading processes and impacts. The treatment of hazards is not intended to be complete for the mountain environment, although potential interactions with phenomena such as snow avalanches and fluvial flash floods are discussed.

As a technical guidance document for practitioners and experts from a range of institutions, the end-user is expected to possess reasonable background knowledge and expertise in the field of hazard assessment. In this regard, the document is not intended to provide fundamental step-by-step prescriptive guidance. Rather, the overall aim of the document is to provide a concise compilation of the state of knowledge and best practices related to glacier and permafrost hazard assessment.

*This weADAPT article introduces the original text, which can be downloaded from the right-hand column. Please access the original text for research purposes, full references, or to quote text. 

This technical guidance document is also available in Spanish and Russian.

Read how this technical guidance document is helping to meet the growing threat from glacial lake outburst floods in the Indian Himalayas >

Document structure

  • Part I of the guidance document provides an introduction to climate change and evolving mountain landscapes and key definitions.
  • Part II provides a review of key processes and their interactions; the intention here is to provide the reader with the latest state-of-the-art knowledge needed to inform the subsequent hazard assessment presented in Part III.
  • Part III introduces the conceptual framework of the hazard assessment, and guides the reader systematically through its core components. Key factors to be considered within the susceptibility assessment are outlined in a series of check-list tables, providing a valuable resource for practitioners.

Throughout the guidance document, reference is made to case-studies and examples from the international literature. Finally, further technical details on available modelling tools for the hazard assessment are provided in Appendix 2, with a complete listing of literature cited in the document given in Appendix 3.

Overview of the framework for glacier and permafrost hazard assessment

This guidance document outlines a systematic approach for the assessment of glacial and permafrost hazards - see pages 27-54 for full details.

This framework (see figure 12 below) addresses two underlying core requirements for hazard assessment, namely, the importance of developing and maintaining inventories of past events, and in the context of a rapidly changing climate, the need for robust climatic data to underpin the assessment.

Based on the state-of-the-art presented in Part II of the technical guidance document, this framework guides the reader through the key considerations and latest methodological approaches for the assessment of glacier and permafrost hazards in mountains, with an emphasis on hazard mapping.

Two core components (or outcomes) of the hazard assessment process are distinguished:

  • Susceptibility and stability assessment: Identifying where from, and how likely hazard processes are to initiate.
  • Impact assessment: Identifying the potential threat from the hazard for downslope and downstream areas, and providing the scientific basis for decision making and planning.

Note that the framework addresses the potential physical impact only, whereas any assessment of societal impacts, damage, and losses, falls within the realm of risk assessment and is outside the scope of this document. The framework is not prescriptive, but rather is intended to guide the practitioner and expert systematically and comprehensively through the assessment process. At each stage of the assessment, various tools and methodologies are available and should in each case be tailored to the local context and needs. The framework is also intended to be generic enough to guide assessment studies at a range of scales, from regional to local site-specific.

The scale of any assessment will depend on the questions being investigated, e.g., what hazard does a particular lake pose (site-specific), or how hazards threaten hydropower development in a particular river basin (regional scale). As a study advances from considering susceptibility and stability through to impact assessment, the relevance and usefulness for local authorities tasked with disaster risk reduction and climate change adaptation generally increase. Where data and expertise allow, an ultimate end-goal could be the development of physical numerical model-based hazard maps, validated and fine-tuned with field studies, and translated into recommendations for planning. However, this may not be feasible or desirable in all cases, and other valuable outcomes can be foreseen based on simplified first-order approaches and expert assessment.


Figure 12 from page 28 of the full text

 

Further resources