New Mexico Geological Society Annual Spring Meeting — Abstracts

Application of HydroGeoSphere to model three-dimensional hydrological processes in the Valles Caldera watershed, New Mexico: Preliminary results

Mountainous watersheds in northern New Mexico provide an important source of recharge to the hydrologic system in this predominantly water-limited southwestern state. The Valles Caldera watershed in the Jemez Mountains is particularly interesting because of its topoclimatological, edaphic, and geological complexities that together give way to intricately complex surface hydrology that is intimately coupled with equally complex hydrogeologic processes. Precipitation, evaporative demand, and snowmelt dynamics depend strongly on orographic processes along with spatially distributed plant community characteristics. Soil characteristics vary greatly in space due to local geomorphology—from coarse on high-gradient resurgent and extrusive domes to fine in the low-gradient Valle Grande. Underlying the soil lies vastly complex surficial geology resulting from the Caldera’s long geologic history of volcanism, uplift, landslides, and lake sediment accumulation.These complex spatially distributed processes and characteristics result in highly three-dimensional hydrologic processes.Modern distributed-parameter, coupled surface-subsurface hydrologic models such as HydroGeoSphere are capable of representing all of the aforementioned spatially variable hydrologic processes—precipitation (including snowmelt), evapotranspiration, variably saturated flow, coupling between surface and subsurface domains, overland flow, and channel flow—thereby fully accounting for the three-dimensionality in complex systems such as Valles Caldera. This presentation describes our strategy and progress in parameterizing and applying the HydroGeoSphere model to the Valles Caldera watershed. Specifically we will present our parameterization scheme, early model output, challenges we have experienced, and future directions.