The component modeling team aims to quantify the spatial and temporal distribution of individual water balance components in a target watershed and to identify the dominant surface and sub-surface flow mechanisms that contribute to streamflow. The 1-D vertical and 3-D numerical models used are informed by meteorological observations, snow-soil sensor data, geophysical measurements of sub-surface properties, and streamflow data. We will test two hypotheses for the snow-dominated Libby Creek watershed in the Snowy Range:
- The relative contributions of both soil evaporation and plant transpiration to the annual water balance decrease with increasing elevation due to a more persistent snow pack at higher elevations and a shorter growing season.
- Streamflow in the Libby creek sub-watersheds is mostly driven by snow melt with vertical downward soil water flow followed by lateral subsurface flow through the fractured upper part of the gneiss and schist bedrock being the dominant pathway
The research plan will include (1) 1-D vertical modeling of soil-plant-atmosphere water and heat exchange to estimate the contributions of snow sublimation, soil evaporation, plant transpiration, and lateral and downward subsurface flow to the annual water balance for selected sensor locations in the Libby Creek watershed; (2) distributed 1-D vertical modeling of soil-plant-atmosphere water and heat exchange to estimate the spatial and temporal variability in the annual water balance components for the entire Libby Creek watershed; and (3) 3-D numerical modeling of surface and sub-surface water flow to estimate the contributions of overland flow, lateral subsurface flow, and deep percolation to streamflow for sub-watersheds.