| Abstract: |
Upon completing Vermont's "local resolution" implementation of the National Hydrography Dataset (NHD), i.e., the Vermont Hydrography Dataset (VHD) in 2005, additional efforts in the past two years have enriched the dataset further with stream perenniality and "Value Added Attributes" (VAAs). These have been done in cooperation with the United States Geological Survey and the University of Vermont, respectively. Employing GIS to evaluate explanatory variables for selected points along a stream, "break points" were identified using a statistically derived "Logistic Regression Equation", to predict stream perenniality, i.e., "perennial" or "intermittent". VAAs, a component of the "NHDPlus" application suite currently being applied nationwide to the medium resolution (1:100k) NHD data, were generated for the VHD to produce attributes that enhance navigation, analysis, modeling and display capabilities. In contrast to all these "enrichments", a simplified version of the VHD (VHDCarto) is now available for straight cartographic work and basic analysis. A review of these development efforts, the application of the VHD to the Digital Flood Insurance Rate Maps (DFIRMs) and the recently initiated "Stewardship" endeavor (maintenance and updates) will be conducted to bring users up to date on the VHD. |