Glacial Hazards in Chile: Processes, Assessment, Mitigation, and Risk Management Strategies

Glacial Lake Outburst Floods (GLOFs) pose a significant hazard to communities and infrastructure in many mountainous parts of the world, including Chile and a number of other lower income countries. This GLOF hazard has increased over the last century as glaciers recede in response to global climate change forming a growing number of glacial lake systems. Outburst floods can occur anywhere that water is stored beneath or on the surface of a glacier, where water becomes ponded behind an ice front or ice dam, or where water is stored in proglacial lakes that develop between a moraine and a receding glacier margin. Lakes in the latter category (moraine-dammed lakes) are particularly hazardous because a sudden collapse of the moraine dam can trigger the release of large volumes of ponded water. In Peru alone, outburst floods from glacial sources caused ~ 32,000 deaths in the 20th century, as well as destroying vital economic infrastructure, settlements and valuable arable land. In the Nepal Himalaya, it has been estimated that the costs associated with the destruction of a mature single hydropower installation by an outburst flood could exceed USD 500 million. Ice-dammed and moraine-dammed lakes are now developing in Chile as glaciers recede. They pose an ever-increasing threat to communities and infrastructure downstream.

This project will answer questions concerning the past, present and future glacial hazards in Chile. We will assess their changing magnitude, frequency, and distribution under current and future global climate change. We will produce the first complete inventory of historical GLOFs in Chile and identify sites that have the potential to develop glacial hazards in the future. We will use physically-based numerical models to simulate GLOFs at sites identified as posing a high hazard and use these simulations to make hazard and flood risk predictions that can inform planners and decision-makers in Chile and other lower income countries globally.

The scientific outputs of this project will be:

- A set of numerical climate model projections for glaciated mountain regions of Chile forced by high-end RCPs and using the latest generation of climate model outputs from CORDEX.
- An enhanced understanding of the physical processes that govern the development of Glacial Lake Outburst Floods (GLOFs) in Chile.
- An assessment of the effects of GLOFs on Chilean social and economic systems, now and in the future.
- An assessment of the potential future implications for GLOFs in Chile and in other lower income countries globally.

We will publish the results from our research in peer-reviewed journals and present them at international conferences but we anticipate that these scientific outputs can be translated more widely because they are of interest to scientists, social scientists, planners, NGO's and Governments who need to understand better natural hazard identification and mitigation and risk and resilience. Direct beneficiaries of the proposed project will therefore include climate change adaptation specialists and infrastructure developers who need to be able to recognize those glacial lake systems that might develop outburst floods.

The project has wider implications for climate change adaptation policy. Globally, the results will be of interest to planners developing risk assessments for understanding the natural hazards associated with the worldwide recession of mountain glaciers, and who need the evidence-base upon which to build adaptation and mitigation policy. The importance of this is highlighted by the work that Harrison and colleagues has undertaken with the Chilean Government (Workshops in 2010 in Santiago and Coyhaique with government officials and planners) which aimed to assess the future dynamic evolution of the icefields and the likelihood of a future increase in glacier hazards. Such concerns are motivated by plans to use water supplies in several mountain regions of Chile for HEP schemes and understanding glacier dynamics and hazards is of high interest to such programmes. The project will also engage with the insurance and re-insurance industry who require empirical data on which to price insurance risks for infrastructure and to gauge the risk exposure of companies in regions where receding glaciers produces downstream hazards.

We will engage with these groups in a number of ways. Harrison has considerable experience in working with insurance companies, actuarial groups and governmental organizations in the field of climate change risk management (including the 2005 Lloyd's Risk Lecture; 2006 invited lecture to the US National Academy of Sciences on climate change risks and business; research funded by UK Foreign and Commonwealth Office on climate change and impacts in Russia). We will engage with these user groups by providing training seminars, workshops and briefing lectures to actuaries and policymakers. The results of our work will be placed on a new project website for access by the general public, with links to information on our publications, photographs and links to climate change and glaciology science websites. We will also use new methods of engaging the public, including posting video clips and computer model simulations and animations on the project website and on YouTube. Computer model simulations and animations will also be available to download on iTunes U as part of a mini-lecture and posted on the project website.

We will also hold an end-of-project knowledge exchange workshop in Nepal to ensure that our results are disseminated to those other DAC-listed countries where the GLOF hazard is likely to increase in the future as glaciers recede in response to climate change.