HydroDS: Data Services in Support of Physically Based, Distributed Hydrological Models

Physically based distributed hydrologic models require geospatial and time-series data that take considerable time and effort in processing them into model inputs. Tools that automate and speed up input processing facilitate the application of these models. In this study, we developed a set of web-based data services called HydroDS to provide hydrologic data processing ‘software as a service.’ HydroDS provides functions for processing watershed, terrain, canopy, climate, and soil data. The services are accessed through a Python client library that facilitates developing simple but effective data processing workflows with Python. Evaluations of HydroDS by setting up the Utah Energy Balance and TOPNET models for multiple headwater watersheds in the Colorado River basin show that HydroDS reduces the input preparation time compared to manual processing. It also removes the requirements for software installation and maintenance by the user, and the Python workflows enhance reproducibility of hydrologic data processing and tracking of provenance

Enhancements to TauDEM to support Rapid Watershed Delineation Services

Watersheds are widely recognized as the basic functional unit for water resources management studies and are important for a variety of problems in hydrology, ecology, and geomorphology. Nevertheless, delineating a watershed spread across a large region is still cumbersome due to the processing burden of working with large Digital Elevation Model. Terrain Analysis Using Digital Elevation Models (TauDEM) software supports the delineation of watersheds and stream networks from within desktop Geographic Information Systems. A rich set of watershed and stream network attributes are computed. However limitations of the TauDEM desktop tools are (1) it supports only one type of raster (tiff format) data (2) requires installation of software for parallel processing, and (3) data have to be in projected coordinate system. This paper presents enhancements to TauDEM that have been developed to extend its generality and support web based watershed delineation services. The enhancements of TauDEM include (1) reading and writing raster data with the open-source geospatial data abstraction library (GDAL) not limited to the tiff data format and (2) support for both geographic and projected coordinates. To support web services for rapid watershed delineation a procedure has been developed for sub setting the domain based on sub-catchments, with preprocessed data prepared for each catchment stored. This allows the watershed delineation to function locally, while extending to the full extent of watersheds using preprocessed information. Additional capabilities of this program includes computation of average watershed properties and geomorphic and channel network variables such as drainage density, shape factor, relief ratio and stream ordering. The updated version of TauDEM increases the practical applicability of it in terms of raster data type, size and coordinate system. The watershed delineation web service functionality is useful for web based software as service deployments that alleviate the need for users to install and work with desktop GIS software

A CyberGIS Approach to Generating High-resolution Height Above Nearest Drainage (HAND) Raster for National Flood Mapping

This paper describes the computational experience of generating the first 10m-resolution Height Above Nearest Drainage (HAND) raster data for the conterminous U.S. using the National Science Foundation (NSF) CyberGIS Facility based on the ROGER supercomputer. The HAND experiment is a joint effort with the NSF HydroShare project and the National Water Center for developing national-scale inundation mapping methodologies and data