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StreamStats Data Preparation Workshop. October 21-22, Nashville Tennessee Pete Steeves, USGS MA-RI District Al Rea, USGS ID District. Overview—Streamflow Statistics (StreamStats). What—Estimate of streamflow under some condition, e.g. the 100-year flood flow
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StreamStats Data Preparation Workshop October 21-22, Nashville Tennessee Pete Steeves, USGS MA-RI District Al Rea, USGS ID District
Overview—Streamflow Statistics (StreamStats) • What—Estimate of streamflow under some condition, e.g. the 100-year flood flow • Why—Bridge or culvert design, flood control, discharge or withdrawl permits, endangered fish habitat, water rights, TMDL’s, etc. • How Computed— • At stream gages: statistical analysis of historic flows • Ungaged sites: Regression equations StreamStats Data Prep Workshop Oct 21-22, 2003
Streamflow Regression Equations • Regression equations take the form:Q100 = 0.471A0.715E0.827F0.472 • Drainage area is used in nearly all equations • Other common variables include: • Basin slope, relief, or mean elevation • Precipitation (mean annual; 2-year, 24-hour) • Stream length or slope • Land use (forest area, wetland and water areas) • Basin shape or orientation • Soils or surficial geology StreamStats Data Prep Workshop Oct 21-22, 2003
The need for GIS-based tools • Cost—Reduce time to delineate and compute basin characteristics from hours to minutes • Accuracy—Some measurements much better, others about the same as manual methods • Consistency—Important for statistical validity • Web-based tool provides broad access to: • Large geospatial data bases • Consistent methods and data StreamStats Data Prep Workshop Oct 21-22, 2003
ArcHydro and StreamStats • ArcHydro provides basics: • Data structure and data management • Global Basin Delineation and other tools • StreamStats adds: • Basin characteristics computation, summarization • Management of equation database • Regression equation solver • Web interface StreamStats Data Prep Workshop Oct 21-22, 2003
System Design – Core Concepts Map Server (ArcIMS) Client (IE 5.5) Data Server (ArcSDE) Web Server (IIS, ASP) Client (IE 5.5) Client (IE 5.5) Application Server (ArcMap, NFF) Database (SQL Server) StreamStats Data Prep Workshop Oct 21-22, 2003
StreamStats—Accomplishments: • Added measurement of basin characteristics to ArcHydro • “Desktop Tool” working in ArcMap 8.2/8.3 • Basin characteristics needed for Idaho (except MCS) • Basin area • Mean elevation • Relief • Mean slope • Percent of basin area >= 30 % slope • Percent of basin area >= 30 % slope and North-facing • Mean annual Precipitation • Percent Forested area
StreamStats—Accomplishments: • Database development—Idaho • ArcHydro data for Salmon and Clearwater River basins, 18 HUCs • Partial processing completed for remaining 120 HUCs • Base map material for Web site completed, covering all Idaho plus large margin StreamStats Data Prep Workshop Oct 21-22, 2003
StreamStats—Accomplishments: • Prototype Web-Based Application for ID • User interface mostly complete • Base maps complete for ID • Basic watershed delineation • Basin characteristics computation • Interfaces with NFF to solve equations • Download watershed shapefile with attributes • Print maps shown in map frame • ESRI contract, partly done through CRADA StreamStats Data Prep Workshop Oct 21-22, 2003
StreamStats—To be done: • Testing, Testing, Testing • Load testing • Will multiple users crash it? • Are time-out errors acceptable? • Fix a few minor bugs • Add monthly flow exceedance estimates StreamStats Data Prep Workshop Oct 21-22, 2003
StreamStats—To be done: • To take web site public we must first: • Write data-set documentation (metadata) • Write general documentation, tutorials, caveats and disclaimers • Continue verification that results are comparable to those used for development of regression equations • Complete ArcHydro data development for remainder of Idaho • Initially exclude monthly flow exceedance computations requiring main channel slope • Display gage statistics database
StreamStats—Future Developments: • Phase 2 Plans for Fall 2003 • Make several improvements to the user interface • Allow user edits to watershed polygon • Better integration with NFF, improved reporting of results • Display stream-gage data from StreamStatsDB • Assess multi-user performance issues—find bottlenecks • Start on multi-state issues, implementation docs • If possible, begin serving parts of New England pilot (NH, VT, MA) StreamStats Data Prep Workshop Oct 21-22, 2003
StreamStats—Future Developments: • Phase 3 Plans for FY2004 (subject to change) • Multistate issues—scaling and implementation • Performance issues—especially in multiuser environment • Add computation of Main Channel Slope • Extending channel to divide was manual process for Idaho • ESRI implementing automated process in ArcHydro • Extensive testing needed • Batch delineation (desktop tool only) • Channel elevation profile artifact removal • Drainage-area ratio method with nearby gages • Tie to National Hydrography Dataset (NHD)
For more info: • Kernell Ries, USGS Marylandkries@usgs.gov • Al Rea, Jacque Coles, USGS Idahoahrea@usgs.gov, jdcoles@usgs.gov • Pete Steeves, USGS Massachusetts psteeves@usgs.gov • StreamStats Web Sitehttp://water.usgs.gov/osw/programs/streamstats.html StreamStats Data Prep Workshop Oct 21-22, 2003
National Streamstats GIS Data Components • Datasets developed for the purpose of delineating accurate basin boundaries • Datasets developed for determining basin characteristics • Fixed stations and related data • Basemap datasets StreamStats Data Prep Workshop Oct 21-22, 2003
Flexible Approach with Standard Methods • StreamStats is designed to be flexible in handling local data • StreamStats will provide a set of standard definitions for basin characteristics • Data must be in the ArcHydro data model, with a few extra naming requirements • DEMs could be from any source or scale • Users can add definitions/data as needed StreamStats Data Prep Workshop Oct 21-22, 2003
Base Maps • Whatever needed to locate points of interest • Primarily 1:24,000 Digital Raster Graphics (DRG) • NHD for reach-based locations • Prefer National data sets StreamStats Data Prep Workshop Oct 21-22, 2003
Approaches For Developing Basin Delineation Datasets • EDNA (stage 1b) • NHD Watershed preprocessing steps (http://nhd.usgs.gov) • ArcHydro ‘Terrain Preprocessing’ steps from a DEM StreamStats Data Prep Workshop Oct 21-22, 2003
Data Requirements—ArcHydro Tools • Grids: Can be in a tiled data structure • Filled DEM (fil) • Flow Direction (fdr) • Flow Accumulation (fac – used to create str) • Streams (str) • Vectors: ArcHydro data model • Catchments • AdjointCatchments • StreamLines • Global data sets Globally Unique HydroID’s StreamStats Data Prep Workshop Oct 21-22, 2003
Directory Structure StreamStats Data Prep Workshop Oct 21-22, 2003
Terrain Preprocessing StreamStats Data Prep Workshop Oct 21-22, 2003
Global Data Sets • All in Global.mdb geodatabase • hucpoly (tile boundaries) • streams (network to connect tiles) • hucpoints (outlets for tile polys) StreamStats Data Prep Workshop Oct 21-22, 2003
Global Network StreamStats Data Prep Workshop Oct 21-22, 2003
Building the Global Network • Must build a Geometric Network of streams • Just need mainstem streams needed to connect our data tiles (8-digit HUCs) • Must specify a sink at outlet, compute flow directions StreamStats Data Prep Workshop Oct 21-22, 2003
Geometric Network Wizard • Build from existing features • Use hucpoint and hucpoly feature classes • Name network HUC_Net • Build complex edges from streams feature class • Use 2-m snap tolerance, both sets of features • Include sources and sinks on hucpoints • Do not assign weights StreamStats Data Prep Workshop Oct 21-22, 2003
Set Flow Directions on Network • Select outlet hucpoint • Set Ancillary Role to Sink • Click Set Flow Direction button on Utility Network Analyst Toolbar StreamStats Data Prep Workshop Oct 21-22, 2003
Make Relationship Class HUCHasJunction StreamStats Data Prep Workshop Oct 21-22, 2003
Make Relationship Class HUCHasJunction StreamStats Data Prep Workshop Oct 21-22, 2003
Store Area Outlets • ArcHydro Tools Toolbar • Attribute Tools pulldown • Or assign thesemanually StreamStats Data Prep Workshop Oct 21-22, 2003
Preprocess Basin Characteristics • ArcHydro Tools…Attribute Tools… Get Parameters • Do this for each hucpoly polygon StreamStats Data Prep Workshop Oct 21-22, 2003
Compact and Repair DataBase StreamStats Data Prep Workshop Oct 21-22, 2003
National Streamstats GIS Data Components • Datasets developed for the purpose of delineating accurate basin boundaries • Datasets developed for determining basin characteristics • Fixed stations and related data • Basemap datasets StreamStats Data Prep Workshop Oct 21-22, 2003
Approaches For Developing Basin Delineation Datasets • EDNA (stage 1b) • NHD Watershed preprocessing steps (http://nhd.usgs.gov) • ArcHydro ‘Terrain Preprocessing’ steps from a DEM StreamStats Data Prep Workshop Oct 21-22, 2003
Why take the EDNA (stage 1b) Approach? • It is available for the project nationwide • A good foundation dataset with minimal additional processing required • May be the best option for states with limited resources StreamStats Data Prep Workshop Oct 21-22, 2003
Why take the NHD Watershed Preprocessing Approach? • Take advantage of higher quality local datasets (hi-res NHD, WBD) • Better match with primary basemap (DRGs) • Horizontal union of 3 primary physiographic datasets (elevation, basin boundaries, hydrography) • Better match with NHD and WBD for spin-off applications StreamStats Data Prep Workshop Oct 21-22, 2003
Determining the Best Option For Your State • 3 National Datasets will guide States to determine best option: • NHD • WBD • NED StreamStats Data Prep Workshop Oct 21-22, 2003