Water Resources Research Act Program

Details for Project ID 2007MT148B

Historical and Future Streamflow Related to Small Mountain Glaciers in the Glacier Park Region, Montana

Institute: Montana
Year Established: 2007 Start Date: 2007-03-01 End Date: 2009-02-28
Total Federal Funds: $17,882 Total Non-Federal Funds: $35,764

Principal Investigators: Joel Harper

Project Summary: More than 37 glaciers currently exist in the Glacier National Park. The annual water runoff from just 1 km2 of glacier is on the order of 6x106 m3. Glacier Park glaciers were significantly larger and more numerous a century ago. The reduction in the area of NW Montana covered by glacier ice has likely caused reduced late summer flows in streams and can be expected to continue to reduce late season river water resources in upcoming decades. To interpret this effect in our historical records, and to forecast its impact on future water resources and associated ecological and human issues, we must have a solid understanding of the contribution glaciers make to Montana river flows past, present and future. We will develop and apply new methods for separating the glacier derived component of runoff from the annual hydrograph with glacier covered basins in NW Montana. We will first simulate glacier runoff in the present day by three independent methods. The three methods will allow cross checking of results, and importantly, calibration of a new numerical model for simulating glacier flow dynamics on a large-scale landscape. Calibration of this model will allow proper simulation of future change to glaciers and associated runoff, and reconstruction of past glaciers and their contribution to late season flows in streams. Our work will result in a new method for assessing the impact of climate change and variability on small mountain glaciers. Small glaciers in NW Montana, the Beartooth Range, the Tetons, the Wind River Range, Sierra Nevada, and Cascades provide much needed late season flows when the Western US is typically warm and dry. Glacier runoff is also important in areas of the developing world including South America and Eurasia. On a global scale, current estimates are that the rate of sea level rise from glacier melt is 0.98 0.19 mm/yr, which demonstrates the importance of developing better methods for assessing future glacier change.