Abstract

Climate change has the potential to greatly influence hydrologic systems in hydroclimatically sensitive regions, such as in mountainous regions in the western United States. For example, a relatively minor decrease in precipitation or increase in temperature might significantly influence a region’s snowpack. This, in turn, affects other hydrologic variables such as evaporation, transpiration, soil moisture, and ultimately, streamflow. Furthermore, different portions of the landscape likely have different responses to such changes because of variations of energy and the way that water gets used by the ecosystem or lost to non-ecosystem processes. In this study, we use high resolution distributed landscape modeling to try to infer how small changes in temperature and precipitation might influence a region’s water budget, paying particular attention to different responses on adjacent landscape units with different elevations and slope characteristics (aspect and gradient). We will use an energy balance snow model coupled with a root zone water balance model with spatial and hydrometeorologic data from the Valles Caldera, New Mexico, USA, which is located in the extreme southern portion of the Rocky Mountains. Early model results suggest that 1) areas where the wintertime snowpack is shallow or does not persist through the entire winter see the greatest changes under different climate conditions, 2) a vast majority of drainage from the root zone occurs during the spring months at higher elevations and is associated with snowmelt, and 3) drainage usually occurs earlier in the season on south-facing aspects than on north facing ones. This study will yield beneficial information about water storage dynamics on adjacent landscape units with different topographic characteristics, as well as information that might be beneficial to water managers planning for droughts, floods, and a changing climate.

Citation

Broxton, P.D., Troch, P.A., Brooks, P.D. (2010): Can Landscape Heterogeneity Buffer or Exacerbate Changes in Mountain Hydrology under Different Climatic Conditions?. AGU Fall Meeting (Poster) Abstract H33C-1143..