Modelling glacial overdeepenings and future lake locations for the western Canadian Cordillera

对加拿大西部科迪勒拉冰川过度加深和未来湖泊位置进行建模

• 批准号: NE/T014202/1
• 负责人: Neil Ross
• 金额: $ 1.17万
• 依托单位: Newcastle University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FT014202%2F1
• 关键词: Modelling; glacial; overdeepenings; future; lake

Mountain glaciers are melting at an increased rate due to climate change; this is leading to decreasing water resources for the surrounding communities, which is becoming of increasing importance in western Canada as glacier volume is expected to reduce by 70% by 2100. As a glacier melts, a lake can be formed in front of the glacier. This lake is formed due to a depression (herein called 'overdeepenings') in the landscape which has been scraped out by glacial erosion, this then fills with the generated melt water once the glacier retreats out of it and can then become dammed by deposited moraines. As these lakes continue to develop and grow, while the glacier continues to shrink, they have the potential to become hazardous, if a sudden release of water occurs, while they can become opportunities for economic benefits - such as hydroelectric dams and tourism - when the glacier disappears.Research on the formation and development of these glacial lakes has been discussed at length within the literature and is well understood. The vast majority of the research at present has focused on these glacial lakes as hazards, focusing on negative impacts such as; decreasing water resources, and the effects on downstream communities. A question which has received very little attention in the literature - and that shall be answered by this study - is that of where these glacial lakes will develop in the future as global warming causes glaciers to disappear and what these locations will look like as these, now relic, lakes dominate the environment?A limited number of studies have been trying to answer this question in to where these glacial lakes will be in the future, with a primary focus on locations of relatively important consequence, for example the Himalaya-Karakoram region. Another study, taking a more global perspective, looked into the possibility of these lakes for hydroelectric dams, which would be important contributions to national energy supplies in many countries. Both studies used estimated glacial ice thicknesses to predict where these overdeepenings have been located. Although these studies provide an understanding on the formation of future lakes, and how they will evolve, no study has tried to describe or understand what these locations will look like once these glaciers disappear and the lakes are all that remain. This study shall be working in British Columbia and Alberta in western Canada, where we shall predict where these glacial overdeepenings are under the present-day glacial ice. This shall be done by using already created estimations on global glacial ice thicknesses, and digital elevation models. These shall be used to estimate the depth and volume of lakes which maybe created in the future. We shall then compare what these future landscapes shall look like using modern day locations which are either transitioning from a glaciated to deglaciated environment with glacial lakes dominating the landscape (Cordillera Blanca, Peru), and locations that are entirely deglaciated and that the once glacial lakes, now remain (e.g. The Lake District, UK). In these localities, mapping of the moraine dams will aid in providing an understanding of where future lakes may develop. The output of this research will aid in giving an understanding on the location of future lakes within western Canada, which will assist in future decision making of the local government into water availability in an unpredictable climate.

由于气候变化，山区冰川正在以更快的速度融化;这导致周围社区的水资源减少，这在加拿大西部变得越来越重要，因为冰川体积预计到2100年将减少70%。当冰川融化时，在冰川前面会形成一个湖。这个湖是由于地形中的一个凹陷（这里称为“过度加深”）而形成的，这个凹陷是由冰川侵蚀刮出的，一旦冰川退缩出来，就会充满所产生的融水，然后可以被沉积的冰碛物堵塞。随着这些湖泊的不断发展和增长，冰川不断缩小，如果突然放水，它们可能变得危险，而当冰川消失时，它们可能成为经济利益的机会--如水电大坝和旅游业。关于这些冰川湖的形成和发展的研究在文献中已经详细讨论过，并且很好理解。目前绝大多数的研究都集中在这些冰川湖的危害，重点是负面影响，如减少水资源，对下游社区的影响。一个在文献中很少受到关注的问题--本研究将回答这个问题--是随着全球变暖导致冰川消失，这些冰川湖将来会在哪里发展，以及这些地方会是什么样子，因为这些现在是遗迹，湖泊主宰着环境？有限数量的研究一直试图回答这个问题，这些冰川湖将在未来的位置，主要集中在相对重要的位置，例如喜马拉雅-喀喇昆仑地区。另一项研究从更全球的角度探讨了这些湖泊建造水力发电大坝的可能性，这将对许多国家的国家能源供应作出重要贡献。这两项研究都使用了估计的冰川厚度来预测这些过度加深的位置。虽然这些研究提供了对未来湖泊形成的理解，以及它们将如何演变，但没有研究试图描述或理解一旦这些冰川消失，这些湖泊是唯一剩下的，这些地方会是什么样子。这项研究将在加拿大西部的不列颠哥伦比亚省和阿尔伯塔进行，在那里我们将预测这些冰川过度加深的地方在今天的冰川下。这将通过使用已经建立的全球冰川厚度估计和数字高程模型来完成。这些数据将用于估计未来可能形成的湖泊的深度和体积。然后，我们将比较这些未来的景观应该看起来像使用现代的位置，无论是从冰川环境过渡到冰川湖泊占主导地位的景观（科迪勒拉布兰卡，秘鲁），以及完全冰川消融的位置，曾经的冰川湖泊，现在仍然存在（例如湖区，英国）。在这些地方，冰碛大坝的测绘将有助于了解未来湖泊可能在哪里发展。这项研究的成果将有助于了解加拿大西部未来湖泊的位置，这将有助于当地政府在不可预测的气候条件下对水资源的可用性做出未来的决策。