Snowmelt to Streamflow: The Importance of Groundwater in Mountain Hydrology

Snowmelt to Streamflow: The Importance of Groundwater in Mountain Hydrology

Rosemary W.H. Carroll, Ph.D.-  Associate Research Professor, Desert Research Institute

Wednesday, March 3rd, 2021, 12pm Mountain Time

ZOOM Registration by visiting: https://unm.zoom.us/meeting/register/tJUpcOGvpzoiHdahUiqbYEmeOrP8MZYkDxjE

ABSTRACT

Mountain snowpack is a critical resource for downstream water users around the world and is especially vulnerable to climate change. Deeper groundwater is often poorly represented in mountain hydrology because of lack of data or assumptions that steep topography and lack of storage may limit its influence. Our conceptual understanding of hydrologic partitioning is further complicated by the difficulty of quantifying snow distribution and snowmelt at the watershed-scale, along with the tight coupling of water inputs to vegetation structure and topography. To address these challenges, we combine snow observations across spatial and temporal scales with chemical and isotopic observations, groundwater gas tracers, and a multi-decadal integrated hydrologic model of a Colorado River headwater basin. With this combined observation and modeling framework, research seeks to answer the following questions: (1) how important is groundwater flow to mountain streams, (2) what are the first-order controls on groundwater recharge, (3) how old is baseflow? Lastly, research will touch on monsoon rains and their effect on streamflow as a function of the antecedent snow season.