Glacial Lakes in Peru: Evolution, Hazards and impacts of climate change.

Lead Research Organisation: University of Exeter
Department Name: Geography

Abstract

Glaciers in Peru are undergoing rapid recession in response to climate change and this has helped produce numerous large glacial lakes, many of which are dammed by moraines and are likely to drain catastrophically if the moraine dams fail or are overtopped. A major trigger of lake drainage is rock slides and debris flows into lakes from recently-exposed valley walls and unstable moraines. Glacial Lake Outburst Floods (GLOFs) from these lakes pose a significant hazard to communities and infrastructure and also impact water supplies in the region. In Peru, outburst floods from glacial lakes have caused ~ 32,000 deaths in the 20th century, as well as destroying vital economic infrastructure, settlements and valuable arable land.

Despite the importance of these lakes, there are many unanswered questions concerning their future behaviour and the future risk of GLOFs. For instance, we do not know how many glacial lakes there are in Peru, nor whether these are growing in size, nor whether they are becoming more or less vulnerable to rapid drainage caused by rock slides and debris flows. We therefore do not know which lakes might cause GLOFs, nor whether the risk of GLOFs is increasing or decreasing. As a result, this project will answer questions concerning the past, present and future development of glacial lakes and glacier hazards in Peruvian mountains. We will produce the first complete inventory of glacial lakes in all the glaciated mountain regions of Peru, assess their changes in size over time in response to past and future glacier recession and assess changes in their vulnerability to sudden drainage. We will investigate the changing magnitude, frequency, and distribution of GLOFs under current and future global climate change; produce the first complete inventory of historical GLOFs in Peru and identify sites that have the potential to develop glacial hazards in the future. We will, for the first time, assess the risk of landslides into glacial lakes now and into 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 decision-makers in Peru.
To do this we will focus on five main issues:

1. Glacial lake development and GLOF inventories in the past and present
Using literature, remote-sensing and fieldwork, we will compile an inventory of all glacial lakes and past GLOF sites in the glaciated regions of Peru.

2. Climate modelling
Use the latest generation of climate models to assess mountain areas of Peru at most risk of future warming and precipitation change. This will enable us to identify areas of future lake drainage risk and we will develop a ranking of mountain areas for future risk of lake drainage.

3. Assessment of lake vulnerability
We will identify current and likely future glacier hazards focusing on the developing landslide and debris flow risk as glaciers recede; establish the locations of potential future vulnerable lakes and potential GLOF sites.

4. Model GLOFs.
We will (a) establish the physical processes that govern GLOF behaviour; (b) analyse flood hydrographs of selected former GLOFs to establish downstream impacts.

5. Assess the socio-economic effects of GLOFs in Peru and GLOF prediction: We will (a) identify potential GLOF sites across Peru and assess potential socio-economic vulnerability; (b) reconstruct former GLOFs and their impacts; (c) conduct numerical simulations of downstream impacts for potential GLOF sites.

This proposal is ODA compliant as it will promote the economic development of Peru by providing improved risk reduction methods that can be applied to hydropower projects and high-altitude mines as well as to local communities through relevant government agencies. The GLOF risk protocols developed in this project can be applied to other DAC-listed countries where GLOF hazards exist (e.g. Argentina)

Planned Impact

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. Our work will use climate modeling and numerical modeling of glacier recession to explore the sensitivity of glacier and glacier lake systems to recent climate change and, by analogy, the likely sensitivity of these coupled systems to future warming. 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) and Nepal Government (workshop in 2017) which aimed to assess the future dynamic evolution of glaciers and 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 and in the Himalaya 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. In addition, the results from the research will be used in our undergraduate and postgraduate teaching programmes to educate the next generation of environmental scientists. Harrison is Director of the MSc pathway in Climate Change and Risk Management at Exeter, while Glasser teaches on MSc schemes in Environmental Monitoring & Analysis and Glaciology at Aberystwyth. Numerous modules within these programmes will be informed by this research.
Engagement is assured. 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). He has also advised the Emergency Planning Society on risks from climate change. Harrison leads the Climate Change Expert Committee which reports to the Office for Nuclear Regulation (part of the Health and Safety Executive) and advises them on climate change risks for all nuclear sites in the UK. 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.

ODA compliance will be central to our project. GLOFs triggered by moraine-dam failures have been reported from many DAC-listed countries where the GLOF hazard is likely to increase in the future as glaciers recede in response to climate change. Our GLOF hazard assessment and risk management protocols, to be further developed through this project for Peru, can be directly applied to these other DAC-listed countries. It has been demonstrated in Nepal, for example, that where improved methods of glacial hazard assessment have been applied, there have been significant tangible socio-economic benefits to the most vulnerable communities. Peru's economic development would be enhanced by providing improved risk reduction methods that can be applied to hydropower projects and high-altitude mines as well as to local communities.

Publications

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