Water Rock Glaciers and climate change in the dry Andes of Bolivia: implications for future water supplies

玻利维亚干燥安第斯山脉的水岩冰川和气候变化：对未来供水的影响

• 批准号: NE/H018875/1
• 负责人: Stephan Harrison
• 金额: $ 8.91万
• 依托单位: UNIVERSITY OF EXETER
• 依托单位国家: 英国
• 项目类别: Training Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FH018875%2F1
• 关键词: Water; Rock; Glaciers; climate; change

This project aims to investigate rock glaciers in the arid mountains of Bolivia and assess their future contribution to water supplies in the region. Mountain hydrology plays a crucial role in maintaining social and economic development in many arid regions of the world. However, climate change is leading to recession of mountain glaciers. In Bolivia mountain glaciers have undergone significant melting since the 1950s, and continued predicted warming over the 21st century will result in further glacier recession and eventual disappearance, especially where the glaciers are small. This glacier recession threatens the future water supplies for the cities of La Paz and El Alto, adversely affecting economic development and helping to drive social, political and ecological instability. However, in several of the high arid mountain regions in Bolivia considerable ice is enclosed within rock glaciers, elongate valley-bottom landforms comprising a variable mixture of rock debris and ice. These landforms are an important component of hydrological systems in many mountain systems, transporting large amounts of coarse and fine sediments to valley-bottom locations and forming extensive potential reservoirs of water. With a surface cover of rock debris, the ice content is insulated from low amplitude and high frequency temperature changes and, as a result, rock glaciers are predicted to respond more slowly than ice glaciers to climate warming. Consequently, they have the potential to play an important future role in hydrological systems under conditions of global warming, producing water supplies to mountain communities as glaciers undergo continued recession. Despite this, several obstacles stand in the way of a better understanding of the role that rock glaciers may be able to play in regulating mountain hydrology. First, there have been few systematic inventories of rock glaciers in mountain regions, despite the pressing need to assess the potential of rock glaciers to contribute to water supply. Second, while much is known of the recession of ice glaciers in response to climate change, much less is known of the rock glacier response. Third, there is as yet incomplete understanding of the amount of ice contained within rock glaciers, especially at the regional scale, and this hampers assessments of the importance of these landforms to providing water supply. As a result, this research proposal will address the first two of these problems and aims to provide a data base from which we can begin to answer the third. We will use remotely-sensed data to map the location, areal extent, and form of rock glaciers in the dry Andes of Bolivia over the last 50 years using fine spatial resolution (5 m) optical satellite data and freely available decommissioned CORONA data from the 1960s. We will use these results to assess rock glacier responses to observed climate change over this period which encompasses the time when attribution studies indicate global temperatures responded to greenhouse gas forcing (IPCC 2007).

该项目旨在调查玻利维亚干旱山脉的岩石冰川，并评估其对该地区供水的未来贡献。山水文学在维持世界许多干旱地区的社会和经济发展方面起着至关重要的作用。但是，气候变化导致山地冰川的衰退。自1950年代以来，玻利维亚山冰川已经发生了明显的融化，并且在21世纪继续预测变暖将导致进一步的冰川衰退和最终消失，尤其是在冰川很小的地方。这次冰川衰退威胁着拉巴斯和埃尔托城市的未来水供应，对经济发展产生了不利影响，并有助于推动社会，政治和生态不稳定。然而，在玻利维亚的几个高干旱山区中，岩石冰川中封闭了大量冰，细长的山谷底面积包含岩石碎屑和冰的可变混合物。这些地形是许多山区系统中水文系统的重要组成部分，将大量粗和细的沉积物运送到山谷的位置，并形成了广泛的潜在水库。在岩石碎片的表面盖上，冰含量与低振幅和高频温度变化隔离，因此，岩石冰川的反应比冰冰川对气候变暖的反应更慢。因此，在全球变暖的条件下，随着冰川的持续衰退，他们有可能在全球变暖的条件下在水文系统中发挥重要的未来作用。尽管如此，几个障碍阻碍了人们对岩石冰川在调节山水水文学中发挥的作用的更好理解。首先，尽管迫切需要评估岩石冰川有助于供水的潜力，但山区岩石冰川的系统库存很少。其次，虽然众所周知，冰冰川会响应气候变化而衰退，但对岩石冰川的反应却少得多。第三，尚不完全了解岩石冰川中包含的冰量，尤其是在区域尺度上，并且对这些地貌对提供供水的重要性的评估都受到评估。结果，该研究建议将解决这些问题的前两个问题，并旨在提供数据库，我们可以从中回答第三个问题。在过去的50年中，我们将使用远程感知的数据在玻利维亚干燥的安第斯山脉中绘制岩石冰川的位置，范围和形式，并使用精细的空间分辨率（5 m）光学卫星数据以及从可免费获得的退空的Corona数据中。 1960年代。在此期间，我们将使用这些结果来评估岩石冰川对观察到的气候变化的反应，这包括归因研究表明全球温度对温室气体强迫响应的时间（IPCC 2007）。