New runoff models for complexity of polygonal landscapes

improved modeling of surface & subsurface water flow expected

Biological and environmental researchers with the (U.S.) Department of Energy have developed a new mathematical formulation that appropriately captures the local complexity of land surface and underlying soils, and implemented it in the DOE's Advanced Terrestrial Simulator (ATS) code.

This new ATS feature allows scientists to accurately predict water flows both below and on the surface of landscapes, including partitions between groundwater and surface runoff to streams.

The multi-institutional team of scientists derived and tested this formulation against a series of benchmark problems and found it to be significantly more accurate in representing polygonal landscapes with convoluted soil structures than models previously used to represent these complex landscapes.

Though the new mathematical formulation was derived for the Arctic permafrost landscapes, scientists anticipate that it will more accurately simulate surface and subsurface water flow in complex landscapes, including cases of post-fire storms on patchy burn scars and variable depth of bedrock in a given spatial area.

This new modeling capability provides a significant advance toward better predictions of water availability and quality in a watershed.

polygonal landscape | photo credit U.S. Department of Energy, Oak Ridge National Laboratory
Sample simulation shows a polygonal landscape with variable vegetation cover (green) and surface water (blue) during a rainstorm. Porous, organic-rich soil beneath the vegetation can store a large amount of water, changing the flow of water.