The hydrologic model also reads spatially distributed meteorological data and uses various balance equations to predict snowmelt, soil moisture, and evapotranspiration, as well as discharge at points of interest. Through a series of timesteps, the model accounts for the disposition of water in the form of energy and flow processes. The hydrologic model deals mostly with the movement of water, and does not rigorously treat certain aspects such as thaw depth. For example, the thaw depth determines how much water the underlying soil can absorb and how much will run off, so its accuracy is important in a hydrologic model. However, current treatment of thaw depth in the hydro model is to make it spatially constant and temporally varying as a function of the day of the year.
Thermal model calculates vertical temperature profiles at evenly spaced nodes.
Hydro model calculates runoff and soil moisture storage in channels and elements. Thus, both models were independently mature, but the scope of our investigation focused on the coupling of these two existing models to produce more realistic simulations of the hydrologic and thermal processes in an arctic regime. In a realistic model, the hydrological processes would be influenced by a spatially varying thaw depth throughout the problem domain, and, likewise, the thermal processes which affect the thaw depth would be influenced by changing moisture content throughout the problem domain. Coupling of thermal and hydro models through soil moisture storage, runoff, thawdepth, and soil temperatures. The primary emphasis in this project was to take the existing thermal and hydrological models and couple them so that they ran simultaneously and synchronized at specified intervals in order to exchange pertinent coupling parameters.