Estimating the Future Effects of Forest Disturbance on Snow Water Resources in a Changing Environment

In the Western U.S., approximately 65% of the water supply comes from forested regions with most of the water that feeds local rivers coming from snowmelt that originates in mountain forests. The Rio Grande headwaters (I.e. the primary water generating region of the Rio Grande river) is experiencing large changes to the landscape primarily from forest fires and bark beetle infestations. Already, 85% of the coniferous forests in this region have been affected by the bark beetle, and projections indicate greater changes will occur as temperatures increase. In this area, most of the precipitation falls as snow in the winter, reaches a maximum depth in the late spring, and melts away due to warmer temperatures by early summer. However, the quantity and timing of snow and associated melt processes are highly affected by changes in the forest and can significantly alter the amount of water from the snowmelt that is retained in forest systems.



This work will leverage ongoing USGS based work (partially funded by SC CASC) to develop an important decision support tool for stakeholders in the basin: an integrated snow model capable of accurately estimating the effects of future landscape and climate change in the Rio Grande headwaters on snow water resources. The support tool will use climate scenario data representing a ‘business as usual’ scenario of changing precipitation and temperature through the turn of the century (2100). The tool will also integrate stakeholder defined scenarios to represent changes in the forest (e.g. further bark beetle spread or forest fire activity) based on extremely high-resolution aerial data sets. When the tool is paired with climate data and forest change scenarios, the results can provide managers with a range of options for future water resource planning in the Rio Grande Basin.