| NEARC 2001
National Hydrography Dataset Panel Discussion (2) Coordinated by The second 1.5-hr panel discussion will focus on NHD applications 1. The National Watershed Boundary Dataset (WBD) Presenter: Reed Sims, New England GIS Specialist, Interdisciplinary Resource Technical Team, U.S. Dept. of Agriculture, Natural Resources Conservation Service, Winooski, VT, reed.sims@vt.usda.gov Accurate watershed boundary data is extremely important for modeling and other applications of NHD. Reed will brief us on the status of this important new dataset that is oh, so much more accurate than the old 1:250,000-scale Hydrologic Unit Code (HUC) data.
2. Watershed Delineation Functionality in the NHD ArcView Toolkit Presenter: Pete Steeves, GIS Specialist, USGS MA/RI Water Resources District Office, Northborough, MA, psteeves@usgs.gov Watershed delineation functionality has been built into the NHD ArcView Toolkit. The new tools allow the user to delineate a watershed from any point on an NHD reach network where 24K NHD has been developed. Preprocessing of base data layers is necessary for these tools to work in a selected 8-digit hydrologic unit. Pete will showcase the new tools in a pilot watershed, discuss the steps necessary for preprocessing the base data layers, and conclude with several planned applications.
3. Applications of National Hydrography Dataset (NHD) in development by the U.S. Geological Survey (USGS) NH-VT District for statewide and regional projects. Presenters: Richard Moore, Hydrologist, USGS NH/VT Water Resources District Office, Pembroke, NH, rmoore@usgs.gov Craig Johnston, Cartographer, USGS NH/VT Water Resources District Office, Pembroke, NH, cmjohnst@usgs.gov Applications of NHD are being developed by the USGS NH-VT District for statewide and regional projects. A Vermont flood frequency project requires the creation of a 1:24,000-scale NHD, and a SPARROW project (SPAtially Referenced Regressions On Watershed Attributes) uses the 1:100,000-scale NHD to cover all of New England. In Vermont, the USGS, in cooperation with the Vermont Agency of Transportation, is developing equations for estimating flow frequency at un-gaged river sites using basin and climate characteristics. These equations require a detailed NHD stream network and associated watershed characteristics. In another project, the USGS, in cooperation with the New England Interstate Water Pollution Control Commission (NEIWPCC) and the U.S. Environmental Protection Agency (USEPA) is preparing a water-quality model, called SPARROW. SPARROW is a spatially detailed, statistical model that uses regression equations to relate phosphorus and nitrogen (nutrient) stream concentrations to pollution sources and watershed characteristics. The New England SPARROW model relies heavily on NHD river reaches and associated watersheds delineated by use of digital elevation models (DEM) and existing National Resources Conservation Service coverages. Characteristics are assigned to each small watershed for model input. Both the Vermont flood frequency model and the New England water-quality SPARROW model are built with NHD river-reach networks. Each of these applications requires specific refinements, adaptations, and processing of the NHD.
4. Tying NHD with Legacy Data and Enhancements for Hydraulic Modeling in New York State Presenters: Tim Daly,
GIS Programmer Ricardo Lopez-Torrijos,
GIS Program Development Coordinator We will focus on applications in use and under development in New York State to link NHD with existing water-related databases, such as the State's Water Quality Classification Database, and other enhancements needed to support hydrologic and hydraulic (H&H) modeling. We will remark on the use of the relational capabilities of NHD for access and analysis of data from mixed GIS/DB/H&H environments, and describe development of interfaces to allow users access to all of these databases through interactive forms and mapping. Tools based on the NHD data structure, such as stream ordering, will be included to allow users to look at the hydrography from points of view appropriate to their needs. |