Copyright © 2005 ESRI. All rights reserved. H&H Using ArcGIS Introduction to NSS

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved. 2-2 Stream Statistics Background

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved. 2-3 Regression Equations  Used to estimate streamflow statistics for ungaged sites (in uncontrolled flow environment)  Relate streamflow statistics to measured basin characteristics  Developed by all 48 USGS Districts on a State-by-State basis through the cooperative program (usually sponsored by DOT)  Often not used because of large efforts needed to determine basin characteristics  Users often measure basin characteristics inaccurately

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved. 2-4 Need for Streamflow Statistics  Water resources planning, management, and permitting by Federal, State, local agencies  Instream flow determinations for controlling pollution and protecting habitat  Designing and permitting facilities such as wastewater- treatment plants, hydropower plants, and water-supply reservoirs  Designing structures such as roads, bridges, culverts, dams, locks, and levees

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved. 2-5 Example Regression Equation  Regression equations take the form: Q 100 = 0.471A E SH  where: A is drainage area, in square miles E is mean basin elevation, in feet SH is a shape factor, dimensionless

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved. 2-6 Basin Characteristics Used for Peak Flows … and many others

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved. 2-7 Problems in Providing Statistics  Published streamflow statistics for data-collection stations are scattered among hundreds of reports nationally  Many publications are out of date and/or out of print  Labor cost for information requests is high  Streamflow statistics are not available everywhere they are needed

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved. 2-8 Manually Determining Basin Characteristics  A 10-square mile basin takes an hour to a few days, depending on characteristics measured and source material  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

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved. 2-9 Teamwork !  USGS:  Data development, server hosting, parameter extraction methodology, equations, UI design  Aquaterra:  NSS – regression calculator  ESRI:  GIS WEB and desktop implementation, integration, application and system design

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved StreamStatsDB/NSS  StreamStatsDB – database (MS Access) with all the data that were used for derivation of regression equations, and their coefficients (cca. 5,200 gaging stations)  Heavily normalized  All regression equation coefficients  Separate application for database editing  NSS - VB application for computing regression for known input parameters (regression calculator) – peak/low flows, rural/urban (if available)  Uses data from StreamStatsDB so the application does not have to change when the underlying data and equations change

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved StreamStatsDB … and many others

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved NSS

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved Role of GIS

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved Role of GIS  Speedup the process (instead of hours – minutes)  Provide a common (single) access to the methodology (for users and maintenance)  Systematize methodology and datasets used in the process (repeatability)  Provide better tools for deriving characteristics for regression equation determination  Map-based user interface  WEB and desktop implementation based on Arc Hydro

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved WEB vs. Desktop Implementation  Tradeoffs in each implementation  WEB  Centralized location for data and software  End users do not need local software or data  Easy maintenance of the application and data but changes have global scope  Complex hardware and software requirements  Difficult customization  Desktop  Easy local updates to the data (latest and greatest for local area)  Easy modification (full ArcGIS capabilities)  Simpler hardware and software requirements  Can be local (i.e. only local data)  Integrated with other applications

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved Steps in Implementation  Preprocess data (one time operation)  Make sure all parameters can be computed and add functionality if needed  Select point of interest  Delineate watershed  Display results and confirm validity of the area  Compute required characteristics  Determine which characteristics are needed from StreamStatsDB  Call NSS (in the background)  Pass parameters from GIS and save results  Display results

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved Arc Hydro Tools Role  StreamStats fully implemented within Arc Hydro environment  Terrain preprocessing  Local and global watershed delineation  Extracting local characteristics  Assembly of global characteristics  Characteristics developed for StreamStats are available to wider audience (e.g. hydrologic modeling support)  Desktop implementation

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved Arc Hydro Corollary  Define GIS processes for characteristics extraction  Define nomenclature  Characteristics description  Database design (fields names and definitions)  Consistency in development approach

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved Web Implementation

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved Main Site (ID)

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved Main Site - navigation Need to zoom in before watershed delineation tool becomes active: see the stream to snap on

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved Watershed Delineation - WEB

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved Results - WEB  Watershed delineation  seconds, not much difference with respect to size of the watershed  Parameter computations  10s – 1 minute, depends on the region (what parameters to get) and somewhat on the size  Careful with concurrent user demand  wait and wait and …

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved WEB Implementation Issues (1)  Size (20 GB and counting - one state)  Speed (WEB)  Watershed delineation (30 seconds)  Parameter extraction (40 seconds)  Projection issues (display in one projection, analysis in another)  WEB implementation ahead of time  Preprocessing requirements  User desire for interactive operations  Edit resulting watershed before getting characteristics

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved  Inconsistency of parameter extraction techniques between GIS and gage properties (including data sources)  Hefty hardware and software requirements  Multi-state implementation  Implementation support  Implementation on both desktop and WEB  Systematization of data and procedures  Managing scale issues (global delineation)  Cool factor WEB Implementation Issues (2)

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved StreamStats Implementation Activities (7/2005) Source: Red – operational; blue – work in progress

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved Interested in StreamStats for your state?  Contact the USGS Water Resources District Chief for your state:  Also, contact the StreamStats Team:  For more information, see  For downloads, see Source: Al Rea, USGS

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved Desktop Implementation

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved Watershed Delineation - Desktop  Watershed delineation  Use any Arc Hydro technique

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved Results - Desktop  Parameter computations  Use “NSS Get Parameters” function from the NSS ArcMap menu (custom toolbar)  Regression computations  Batch process - use “NSS Batch” function from the NSS ArcMap menu (runs NSS)  Interactive - use “NSS Interactive” function from the NSS ArcMap menu (starts Excel)

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved Interactive Calculator - Desktop  Excel implementation – full flexibility

H&H Using ArcGIS Copyright © 2005 ESRI. All rights reserved Desktop Implementation Issues  Size (can be limited to smaller extents – e.g. Wisconsin has 13 regions)  Speed – faster than WEB implementation due to less overhead and more control over preprocessing  Projection issues (display and analysis in the same projection)  Proven technology  Interactive operations  More control over the computations (can “play games” – sensitivity analysis) – can easily implement their own equations on different data  Easy to add more functionality