StreamStats: Delivering Streamflow Information to the Public By Kernell Ries U.S. Department of the Interior U.S. Geological Survey MD-DE-DC District 410-238-4317 kries@usgs.gov
StreamStats Web Application Provides estimates of streamflow statistics, basin and climatic characteristics, and other information for user-selected points on ungaged streams Automatically measures basin and climatic characteristics for ungaged sites using GIS Provides published streamflow statistics, basin and climatic characteristics, and other information for data-collection stations
StreamStats Team Jacque Coles (ID District) ArcIMS Specialist / Site Administrator Al Rea (ID District) GIS Specialist Pete Steeves (MA-RI District) GIS Specialist Kernell Ries (OSW / MD-DE-DC District) Coordinator / Hydrologist Contractors ESRI, Inc. Application programming / ArcHydro Aqua Terra Consultants NFF Program / StreamStatsDB
Need for Streamflow Statistics Water resources planning, management, and permitting Flood-plain mapping Instream flow determinations for pollution and habitat Design and permitting of facilities such as wastewater-treatment plants, hydropower plants, and water-supply reservoirs Design of structures such as roads, bridges, culverts, dams, locks, and levees
Providing Streamflow Statistics Hundreds of USGS reports contain streamflow statistics for data-collection stations Many publications are out of date and/or out of print Labor cost for information requests is high Streamflow statistics are not available everywhere they are needed
Regression Equations Used to estimate streamflow statistics for ungaged sites Relate streamflow statistics to measured basin and climatic characteristics Developed by all 48 USGS districts on a State-by- State basis through the Cooperative Program Often not used because efforts needed to determine basin and climatic characteristics are very high Users often measure the characteristics inaccurately
Example Regression Equation Regression equations take the form: Q 100 = 0.471A 0.715 E 0.827 SH 0.472 where: A E SH is drainage area, in square miles is mean basin elevation, in feet is a shape factor, dimensionless
Basin Characteristics Used for Peak Flows Basin characteristic # of States using this (including PR) Drainage area or contributing drainage area (square miles) 51 Main-channel slope (feet per mile) 27 Mean annual precipitation (inches) 19 Surface water storage (Lakes, ponds, swamps) 16 Rainfall amount for a given duration (inches) 14 Elevation of watershed 13 Forest cover (percent) 8 Channel length (miles) 6 Minimum mean January temperature (degrees F) 4 Basin shape ((length) 2 per drainage area) 4 Soils characteristics 3 Mean basin slope (feet per foot or feet per mile) 2 Mean annual snowfall (inches) 2 Area of stratified drift (percent) 1 Runoff coefficient 1 Drainage frequency (number of first order streams per sq. mi.) 1 Mean annual runoff (inches) 1 Normal daily May-March temp (degrees F) 1 Impervious Cover (percent) 1 Annual PET (inches) 1
Manually Determining Basin Characteristics A 10-square mile basin can take < 1 hour to > 1 day, depending on characteristics measured, source material, and expertise The required time increases exponentially with increasing watershed area because of the increasing dendritic patterns and logistical problems when matching between map sheets The manual process is not completely repeatable The error introduced by determining basin characteristics probably is as large as the uncertainty in the regression models
Massachusetts Prototype Developed in 1999 using ArcView 3.2/ArcViewIMS Available to public on web since Jan. 2001 at http://ststdmamrl.er.usgs.gov/streamstats/ Very limited ability for expansion to other States
New Prototype Objectives Potential expandability to all States Improved basic functionality Improved statistics database Potential to add other types of data, such as sediment, water use
Development Strategy Same program will run as a dll on a desktop or on the Web Program based on the ArcGIS Hydro-Data Model and Tools (http://www.crwr.utexas.edu/giswr/) Standard GIS methods for measuring basin characteristics will be built into the ArcGIS Hydro Tools Basin characteristics will be pre-processed for previously determined sub-basins At least initially, all GIS data to reside on local server The National Flood Frequency Program (NFF) will solve regression equations
Software ESRI ArcGIS with ArcHydro Tools ESRI ArcSDE Microsoft SQL Server ESRI ArcIMS IIS ASP Tomcat
Programming languages Visual Basic for Applications ArcObjects Javascript XML HTML
StreamStats Components User Interface Streamflow Statistics Database Statistics Calculation Program GIS Database
System Design Map Client (IE 6.0) Client (IE 6.0) Web Server (IIS, ASP) Server (ArcIMS) Data Server (ArcSDE) Client (IE 6.0) Application Server (ArcMap, NFF) Database (SQL Server)
User Interface Displays maps and enables site selection Displays default data layers for selected scale ranges and allows adding/subtracting map layers Zoom and pan to places of interest Zoom to named geographic location or stream Evaluate basin boundaries in the map frame Print maps and download data shown in the map frame
New User Interface at Startup
Statistics Database Includes For data-collection stations: Previously published streamflow statistics Descriptive information, such as station name and number, coordinates, period of record Basin characteristics, such as drainage area, total stream length, mean basin slope For ungaged sites: Data for solving regression equations (NFF)
StreamStatsDB User Interface
StreamStatsDB, cont d Linked to map in user interface showing site locations Built using MS Access and Visual Basic Contains fields for all streamflow and basin characteristics that are currently used, and allows new characteristics to be added Data entered by District office personnel Addition of sediment statistics is planned and other data could be added
Statistics Calculation Program Determines drainage boundaries for userselected sites Measures basin characteristics Runs the National Flood Frequency Program (NFF) Delivers results in pop-up browser window
Example Point Selection
Drainage Boundaries 1. User selects point on stream 2. Point is transferred to a cell in a flow-direction grid derived from a DEM 3. GIS determines boundary from flow-direction grid up to points at which the boundary for the new site intersects boundaries in boundary map layer 4. GIS accumulates all upstream areas and dissolves internal boundaries
Example Drainage Boundary
NFF Program User Interface Solves regression equations for StreamStats
National Flood Frequency Program Solves regression equations for any flow type Provides standard errors, equivalent years of record and/or prediction intervals as indicators of potential errors Computes of region-of-influence estimates, where available Urban equations, drainage-area ratio estimates, and weighted estimates not implemented initially in StreamStats
Example Output
GIS Database Includes Datasets needed to delineate accurate basin boundaries (DEM derivatives, streams, drainage divides) Datasets needed to determine basin characteristics (precipitation, land use, soils, DEM, etc.) Data-collection station locations Basemap datasets (DRG topos, roads, political boundaries, etc.)
GIS Data National map layers used when possible Local map layers used when needed to solve local equations or where better resolution is available Flexibility is key to wide use of application
StreamStats Benefits Published statistics are readily available Ungaged site process takes < 10 minutes Large collections of maps, equipment, and software are not necessary Consistent information delivery Little or no additional error is introduced Only basic understanding of hydrology, computer science, geographic analysis is needed Reduced information requests
Status and Short-Term Plans Prototype working in part of Idaho Implement statistics database and rest of Idaho by 10/03 Implement MA, NH, and VT by 12/03 Implement TN by 3/04
Long-Term Plan Include additional States Add drainage-area ratio estimates Add automated update of non-interpretive streamflow statistics Add methods for regulated streams Add sediment (and possibly other) data Add internal desktop version with batch processing
State Implementation Process Done through cooperative agreements between Districts and local agencies Populate the streamflow statistics database Generate and format any custom GIS data Test accuracy of basin and climatic characteristics and equation results, and summarize results Potentially develop new equations, using GIS data to measure basin characteristics USGS OSW and District concurrence to put on Web
Summary StreamStats Is a Web application that provides estimates of streamflow statistics and other information for gaged and ungaged sites Uses cutting-edge technology to provide the information to the public by running a GIS interactively over the Web Implementation for States will be done through cooperative funding agreements Full implementation will likely take several years
StreamStats web sites Public informational page: http://water.usgs.gov/osw/programs/ streamstats.html Internal application web page: http://streamstats.wr.usgs.gov/ idstreamstats/ NFF Program: http://water.usgs.gov/osw/programs/nffp.html