U.S. Department of the InteriorU.S. Geological SurveyIdaho District Office(208)387-1323ahrea@usgs.gov

Data Requirements for StreamStats

December 18, 2002Alan Rea Peter

SteevesU.S Department of the InteriorU.S. Geological SurveyMassachusetts District Office(508)490-5054psteeves@usgs.gov

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

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

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

Approaches For Developing Basin Delineation Datasets

EDNA (stage 1b) NHD Watershed preprocessing steps (

http://nhd.usgs.gov) ArcHydro ‘Terrain Preprocessing’ steps from

a DEM

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

Directory Structure

Terrain Preprocessing

Global Data Sets All in Global.mdb geodatabase hucpoly (tile boundaries) streams (network to connect tiles) hucpoints (outlets for tile polys)

Global Network

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

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

Set Flow Directions on Network

Select outlet hucpoint Set Ancillary Role to Sink Click Set Flow Direction button on Utility

Network Analyst Toolbar

Make Relationship Class HUCHasJunction

Make Relationship Class HUCHasJunction

Store Area Outlets

ArcHydro Tools Toolbar Attribute Tools pulldown

Preprocess Basin Characteristics

ArcHydro Tools…Attribute Tools… Get Parameters

Do this for each hucpoly polygon

Compact and Repair DataBase

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

Approaches For Developing Basin Delineation Datasets

EDNA (stage 1b) NHD Watershed preprocessing steps (

http://nhd.usgs.gov) ArcHydro ‘Terrain Preprocessing’ steps from

a DEM

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

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

Determining the Best Option For Your State

3 National Datasets will guide States to determine best option: NHD WBD NED