Processes governing the drainage of glacier-dammed lakes; combining field measurements and numerical modeling

Jökulhlaups是由冰川阻塞湖泊的不稳定排水引起的突发洪水。在这种情况下，冰川的流量可以在短时间内增加一个数量级以上。由于其广泛发生和不稳定的性质，jökulhlaups构成了重大的潜在危险，并往往造成重大损害。与jökulhlaups有关的自然灾害的评估和预防需要对突发洪水的性质、时间、持续时间和规模进行可靠的预测。尽管在以前的研究中取得了进展，但仍然缺乏捕捉基本物理学的预测工具。特别是，触发机制仍然不完全理解和控制洪水演变的几个方面没有令人满意的解释。拟议的研究将解决这些问题，使用数值模拟和现场测量相结合。新的计算工具使现在的解决方案的完整系统的方程，从而促进应用程序的模型，以现实的边界条件。在2001年的一次jökulhlaup之后，挪威的一个冰川Blamannsisen筑坝的一个湖泊目前正在重新蓄水，预计将再次蓄水，并预计将在2004年再次引发洪水。这个网站提供了一个很好的机会来收集必要的数据来定义数值模型的边界条件，并验证其结果。

Jökulhlaups are sudden outburst floods caused by the unstable drainage of glacier-dammed lakes. During such an event, the discharge from a glacier can increase by more than one order of magnitude within a short time. Due to their widespread occurrence and their erratic nature, jökulhlaups pose a significant hazard potential and have often caused substantial damage. The assessment and prevention of natural hazards related to jökulhlaups require a reliable prediction of the nature, timing, duration and magnitude of the outburst flood. Despite the advances made in previous studies, there is still a lack of prognostic tools which capture the fundamental physics. In particular, the trigger mechanism remains incompletely understood and several aspects controlling the flood evolution are not satisfactorily explained. The proposed study will address these questions using a combination of numerical modeling and field measurements. Newly available computing tools enable now the solution of the full system of equations thereby facilitating the application of the model to realistic boundary conditions. Following a jökulhlaup in 2001, a lake dammed by Blamannsisen, a glacier in Norway, is currently filling again and is expected again and is expected to lead to another outburst flood in 2004. This site provides an excellent opportunity to collect the data necessary to define the boundary conditions for the numerical model and to validate its results.