Project Overview

Full Title
Development of StreamStats in the Upper French Broad River Basin, North Carolina: A Pilot Water-Resources Web Application

Location
 Transylvania, Henderson and Buncombe Counties

Partner Agencies
North Carolina Department of Transportation

Project Chief
Chad Wagner
cwagner@usgs.gov

Period of Project
2007 - 2008

Team Members
Kirsten Tighe
Silvia Terziotti

Science Topic
Hydrologic and Geospatial data

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Upper French Broad StreamStats

North Carolina StreamStats Approach

Currently (2010) the StreamStats application relies exclusively on 10- and 30-meter Digital Elevation Models (DEMs) and 1:24,000- and 1:100,000-scale National Hydrography Datasets (NHDs). Although these datasets are adequate for some applications, availability of higher resolution elevation data, predominately from Light Detection and Ranging (LIDAR), provides an opportunity to provide more accurate results from StreamStats for a variety of scientific applications. In 2007, the State of North Carolina developed a local-resolution NHD product (at an approximate 1:4,800 scale) for 19 western counties in the State. The best available combination of digital orthophotography, DEMs derived from LIDAR, and existing hydrography was used to create the local-resolution NHD product.

A pilot project was conducted by the USGS, in cooperation with the North Carolina Department of Transportation (NCDOT), to develop and implement a StreamStats application for the upper French Broad River basin in western North Carolina. This StreamStats application interfaces with the local-resolution NHD product, 20-foot DEMs (derived from LIDAR data), and the most current regional streamflow regression equations and datasets of landscape characteristics. Basin characteristics, such as rainfall data, topographic variables (such as slope and drainage area), and best-available land-cover classifications, were incorporated in the pilot StreamStats application.

The North Carolina Center for Geographic Information and Analysis (CGIA) partnered with the NCDOT and USGS on a pilot project to generate high-resolution land-cover data for the upper French Broad StreamStats application. CGIA used visible near-infrared satellite imagery (ASTER) from 2006 to generate a 10-class land-cover dataset for the upper French Broad River basin in the vicinity of Asheville and Hendersonville, North Carolina. Both the 2001 National Land-Cover Dataset (NLCD) and 2006 ASTER land cover data are available in the pilot North Carolina StreamStats application.

North Carolina StreamStats Functionality

Current (2009) functionality for the North Carolina pilot StreamStats in the upper French Broad River basin includes the following:

Figure 1. Example of an automated watershed delineation for a user-defined stream location in StreamStats where the selected site is shown by a dark blue circle with a red cross behind it, the drainage area is shaded magenta and streamgages are shown by the blue triangles.

• View a range of base-map features, such as roads, streams, political boundaries, aerial imagery and USGS topographic maps in the user interface map frame for navigation purposes;

• Use roadway and aerial imagery data layers from NCOneMap [http://www.nconemap.com/], which provides the most up-to-date geospatial data available in participating counties in the State;

• Zoom in or out to a different map scale based on input of (1) a user-drawn rectangle, (2) a place name, (3) coordinates of longitude and latitude, or (4) a specified scale;

• Obtain previously published peak-streamflow statistics, basin characteristics, and descriptive information for USGS data-collection stations, and link to the USGS National Water Information System (NWIS) Web site that provides access to data collected at selected sites;

• Delineate the drainage-basin boundary for a user-selected ungaged site and edit the basin boundary (fig. 1);

• Compute 37 basin characteristics, such as drainage area, stream slope, land cover, soil type, and mean annual rainfall, for the selected site and summarize in a tabular format (fig. 2);

• Estimate peak-streamflow statistics at ungaged locations and provide indicators of the accuracy of the estimates for a site in a tabular format (fig. 3);

• Search upstream or downstream from a selected site to identify the connected stream network and to locate and provide information on natural or manmade features, such as dams and wastewater discharges, that may affect the quantity or quality of the streamflow;

• Download the basin boundary as an ESRI shapefile for use in other applications, along with basin characteristics and streamflow statistics that have been computed for the site;

• Print the results displayed in the user-interface map frame.

Figure 2. Example results of a basin characteristics summary table for the watershed of a user-defined point in StreamStats.	Figure 3. Example of a peak-flow streamflow statistics summary table for the watershed of a user-defined point in StreamStats.

StreamStats Availability and Future Direction in North Carolina

The North Carolina pilot StreamStats application for the upper French Broad River basin can be accessed from the USGS National StreamStats site at http://water.usgs.gov/osw/streamstats/north_carolina.html. This web site provides helpful information for the user, including definitions of basin characteristics, details about the functionality and limitations of the StreamStats application, user-help information regarding how to use StreamStats, and links to access state applications. Although 2006 ASTER land-cover and local-resolution NHD products are not available statewide, StreamStats can be implemented for the remainder of the State by using LIDAR-based topographic data and the best-available land cover and hydrography, which currently (2009) are 2001 NLCD and 1:24,000-scale NHD, respectively.