TopoFlow-Glacier: Modeling combined snow and ice melt in glaciated catchments in Alaska for the NextGen Framework

NOAA Office of Water Prediction’s (OWP’s) Next Generation Water Modeling Framework (NextGen) allows for a mosaic modeling approach to making hydrologic predictions in a single runtime environment. NextGen utilizes the Basic Model Interface (BMI) to exchange information between models and modules. The southern Alaska domain represents a unique landscape as it is ~ 8% glaciated. To estimate combined snow and ice melt that contributes to runoff in glaciated catchments, we developed a new glacier energy balance module as part of TopoFlow, an open source, BMI compatible, modularized, distributed hydrologic model in Python (Peckham et al. 2017). The module was adapted from TopoFlow’s existing snow energy balance module to account for both snow and ice processes. We demonstrate the performance of this new module and how it can be incorporated into the NextGen framework to predict streamflow in a set of test catchments. In an uncalibrated run on a 1 km grid at Wolverine Creek, AK (USGS-15236900) for water years 2017-2018, streamflow simulated with the new glacier module and TopoFlow kinematic wave channel routing produced the same Kling-Gupta Efficiency score (KGE) as the National Water Model version 3.0 simulation (KGE = 0.71). Further, we use TopoFlow to demonstrate how the broader scientific community can contribute new models/modules to NextGen for hydrologic prediction.

Peckham, S. D., M. Stoica, E. Jafarov, A. Endalamaw, and W. R. Bolton (2017), Reproducible, component-based modeling with TopoFlow, a spatial hydrologic modeling toolkit, Earth and Space Science, 4, doi:10.1002/2016ea000237.