Spatially Distributed Hydrologic Modeling

A number of field studies have resulted in a good understanding of many of the arctic energy and hydrologic processes at both the plot and hillslope scales.  However, this understanding gained from field studies has not been adequately or systematically translated into process-based hydrologic models. The primary contribution of this research is to bridge this gap between the plot and watershed-scales through a spatially-distributed, process-based hydrologic  modeling. The model we are using, TopoFlow (http://instaar.colorado.edu/topoflow), will be used as a tool to better understand which energy and hydrologic processes are important at the plot and watershed scales in various permafrost dominated ecosystems.

The two regions we have initially chosen for study are a small sub-basin of the Bayelva watershed located close to Ny-Alesund, Svalbard and a small island, Samoylov, located in the Lena River Delta. There are significant differences between these two study sites. While both of these catchments are underlain with continuous permafrost, Samoylov is characterized as extremely low-gradient and dominated with low-centered polygons. On the other hand, the Bayelva sub-catchment has a higher gradient and is glacially-influenced.

Written in IDL, TopoFlow is a spatially-distributed, process-based hydrologic model. Driven with meteorologic data, TopoFlow is currently able to simulate major water balance components including snow melt, evapotranspiration, ground water flow, and overland/channel flow. Current developmental projects include implementation of the Richardson equation for infiltration and a freeze-thaw algorithm. 

For further information: Bob Bolton