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

由于气候变化，秘鲁的冰川正在经历迅速的衰退，这帮助产生了许多大型冰川湖泊，其中许多湖泊被冰雹筑坝，如果冰凌大坝坍塌或被淹没，很可能会灾难性地流失。湖泊排水的一个主要触发因素是岩石滑坡和泥石流从最近裸露的谷壁和不稳定的冰原流入湖泊。来自这些湖泊的冰川湖暴发洪水(GLOF)对社区和基础设施构成重大危险，并影响该地区的供水。在秘鲁，冰川湖泊爆发的洪水在20世纪造成约32,000人死亡，并摧毁了重要的经济基础设施、定居点和宝贵的耕地。尽管这些湖泊很重要，但关于它们未来的行为和GLOF的未来风险，还有许多悬而未决的问题。例如，我们不知道秘鲁有多少冰川湖泊，也不知道这些湖泊的面积是否在扩大，也不知道它们是否变得更容易受到岩崩和泥石流造成的快速排水的影响。因此，我们不知道哪些湖泊可能导致GLOF，也不知道GLOF的风险是增加还是减少。因此，该项目将回答有关秘鲁山区冰川湖泊和冰川危害的过去、现在和未来发展的问题。我们将编制秘鲁所有冰川山区冰川湖泊的第一份完整清单，评估它们的面积随时间的变化，以应对过去和未来的冰川衰退，并评估它们对突然排水的脆弱性的变化。我们将调查当前和未来全球气候变化下GLOF的大小、频率和分布的变化；编制秘鲁历史上GLOF的第一份完整清单，并确定未来可能发生冰川灾害的地点。我们将首次评估现在和未来山体滑坡进入冰川湖泊的风险。我们将使用基于物理的数值模型来模拟被确定为高危险地点的GLOF，并使用这些模拟来做出灾害和洪水风险预测，以便为秘鲁的决策者提供信息。为此，我们将重点关注五个主要问题：1.冰川湖开发和过去和现在的GLOF名录利用文献、遥感和田野调查，我们将汇编秘鲁冰川地区所有冰川湖泊和过去GLOF遗址的名录。2.气候模型使用最新一代气候模型评估秘鲁山区未来气候变暖和降水变化的风险最大。这将使我们能够识别未来湖泊排水风险的地区，我们将制定未来湖泊排水风险的山区排名。湖泊脆弱性评估我们将确定当前和未来可能的冰川危害，重点是随着冰川消退而形成的滑坡和泥石流风险；确定未来潜在脆弱湖泊的位置和潜在的GLOF地点。我们将(A)建立支配GLOF行为的物理过程；(B)分析选定的以前GLOF的洪水过程，以确定下游影响。5.评估秘鲁地灾的社会经济影响和地灾预测：我们将(A)确定秘鲁各地潜在的旱灾地点并评估潜在的社会经济脆弱性；(B)重建以前的旱灾及其影响；(C)对潜在的旱灾地点的下游影响进行数值模拟。这项提议符合官方发展援助，因为它将通过相关政府机构提供可应用于水电项目和高海拔矿山以及当地社区的改进的风险降低方法，从而促进秘鲁的经济发展。本项目中制定的GLOF风险协议可适用于其他存在GLOF危害的DAC名单国家(如阿根廷)

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 presentUsing 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 modellingUse 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 vulnerabilityWe 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)