Challenges of Predicting the Hydrologic Response of Ungauged Arctic Catchments

Few streams are gauged in the high latitudes and often those streams are gauged under unfavorable conditions in this harsh environment. This, coupled with a changing climate makes it even more challenging to use regional historical data to predict flow in ungauged basins. While it is anticipated that precipitation will increase in a warming scenario, this has not been universally found to be the case. Increasing variability in precipitation patterns and extreme events further increases the difficulty in using relatively short-term data to predict future conditions. Because of the long winters, the snowmelt runoff is guaranteed to be a significant event; however, in the Alaskan Arctic summer precipitation events have produced runoff peaks that are four times greater than maximum snowmelt peak events for some smaller headwater basins. Presently it is difficult to get hydrologic models to capture the wide range of responses that exist from droughts to floods for gauged basins. The need for good predictive models for ungauged basins in light of rapid resource development in this region of the world is crucial for good water-resource management. These models will need to deal more directly with uncertainty and risk evaluation, both due to the limited data and increasing variability in changing climate conditions. The methods to apply data and hydrologic characteristics from regional "index" watersheds will also be critical in improving the methods of simulating flow in ungauged basins.