Interactive Python Widget for Correcting WRF-Hydro Input Grids

The Weather Research and Forecasting hydrological extension package (WRF-Hydro) ArcGIS Preprocessing Toolkit was developed by the National Center for Atmospheric Research (NCAR) to assist WRF-Hydro users in developing hydrologic input grids for the WRF-Hydro modeling system.  Specifically, the toolkit derives input channel and lake grids from a high spatial resolution elevation dataset and a lake polygon shapefile, respectively, to create the channel routing component of the model.  During this process, the lake polygons are rasterized to form the lake grid and used to mask underlying channel components within the channel grid.  Oftentimes, the associated channel components are not completely masked by the lake extent, resulting in the generation of stream artifacts along the lake perimeter.  These stream artifacts must be removed from the channel grid prior to running the WRF-Hydro model in order to properly model channel flow.  Currently, the WRF-Hydro ArcGIS Preprocessing Toolkit does not provide a means of removing these stream artifacts since the errors are unique to each domain and application.  Instead, the task of removing stream artifacts is left to the user.  To assist WRF-Hydro users in removing stream artifacts and correcting other inaccuracies within the routing grids, a fully interactive Python widget, which provides a flexible framework for importing, navigating, and modifying WRF-Hydro input grids, was developed using the Tkinter Python module.  Although the interactive widget was originally designed for WRF-Hydro input grids, the code can be easily modified to accommodate any two-dimensional gridded dataset.  This presentation will provide a basic overview of the Tkinter module, demonstrate the capabilities of the interactive Python widget related to WRF-Hydro applications, and propose additional capabilities that could be supported in future versions.