General Information

Project area general description

The state of Idaho

Are any areas excluded?

The Snake River downstream of the Owyhee River confluence, Clark Fork, Pend Oreille, and Kootenai Rivers

Types of flow statistics available

Peak flows, bankfull flows, low flows, monthly and annual flows

ArcGIS version used for processing

9.2

Was TopoGrid used to process DEMs?

No

DEM and derivatives projection (general description)

NAD_1983_Idaho_TM, vertical datum NAVD 88

DEM and derivatives (fdr, fac, etc.) resolution

10 m

DEM source

One-third-arc-second NED, 2004 http://ned.usgs.gov/

Hydrography source

National Hydrography Dataset (NHD) - High-resolution, 2004 http://nhd.usgs.gov/

Hydrologic unit "walls" source

Draft Idaho Watershed Boundaries Dataset, 200506 http://www.idwr.idaho.gov/watersheds/default.htm

Gage basin boundaries source

not used

Interactive map snapping tolerance

4 cells

Basin characteristics computed using continuous parameter grids (CPGs)

BSLDEM10M, ELEV, FOREST, NFSL30_10M, PRECIP, SLOP30_10M

 

Basin Characteristics Methods and Sources

Variable name in reports

Name

Description

Computation method

Data Source

WRIR 01-4093

WRIR 02-4170

WRIR 03-4261

SIR 2006-5035

SIR 2009-5015

AG_OF_DA

Agricultural Land in Percentage of Drainage Area

percent of area in  categories 81-85

Enhanced NLCD 1992, http://water.usgs.gov/lookup/getspatial?nlcde92

 

 

 

AG

 

BSLDEM10M

Mean basin slope computed from 10 m DEM, in percent

area-weighted mean

bsldem10m, http://water.usgs.gov/lookup/getspatial?ds412_archydrohucs

 

 

 

 

 

BSLDEM30M

Mean basin slope. Computed from 10 m DEM and adjusted to approximate earlier values computed from 30 m DEM.

0.927*BSLDEM10M-0.3021

computed

BS

BS

BS

BS

BS

CSL10_85

10-85 slope, in feet per mile. Computed based on longest flow path using 10-m DEMs and adjusted to approximate earlier measurements done using BASINSOFT.

0.9224*CSL1085LFP+6.6012

computed

MCS

 

 

 

 

CSL1085LFP

10-85 slope based on longest flow path computed using 10-m DEMs, in feet per mile

ArcHydro Tools LFPathOp

Hydro-enforced DEM  derivatives (fdr and dem) http://water.usgs.gov/lookup/getspatial?ds412_archydrohucs

 

 

 

 

 

DRNAREA

Area that drains to a point on a stream, in square miles

polygon area

GlobalWatershed

A

DA

DA

A

A

DV_OF_DA

Developed Land in Percentage of Drainage Area from 1992 NLCD data

percent of area in categories 21-23

Enhanced NLCD 1992, http://water.usgs.gov/lookup/getspatial?nlcde92

 

 

 

DV

 

ELEV

Mean Basin Elevation in feet

area-weighted mean

dem, http://water.usgs.gov/lookup/getspatial?ds412_archydrohucs

E

E

E

 

E

ELEVMAX

Maximum Basin Elevation in feet

maximum

dem, http://water.usgs.gov/lookup/getspatial?ds412_archydrohucs

 

 

 

 

 

FOREST

Percent of area covered by forest

percent of area in  categories 41-43

Enhanced NLCD 1992, http://water.usgs.gov/lookup/getspatial?nlcde92

F

F

F

 

 

IMPNLCD01

Percentage of impervious area determined from NLCD 2001 impervious dataset

area-weighted mean

NLCD 2001 Version 1.0 imperviousness grid http://www.mrlc.gov/nlcd01_data.php

 

 

 

 

 

MINBELEV

Minimum Basin Elevation in feet

minimum

dem, http://water.usgs.gov/lookup/getspatial?ds412_archydrohucs

 

 

 

 

 

NFSL30

Percent of area having North-facing slopes greater than or equal to 30 percent. Computed from 10 m DEM and adjusted to approximate values computed from 30 m DEM.

NFSL30_10M-1.0

computed

 

NF30

NF30

 

 

NFSL30_10M

Percent of area having North-facing slopes greater than or equal to 30 percent, computed from 10-m DEM

percent of area; North-facing defined as Aspect < 60 or > 300 degrees

nfsl30, http://water.usgs.gov/lookup/getspatial?ds412_archydrohucs

 

 

 

 

 

PRECIP

Mean annual precipitation, in inches

area-weighted mean

precip_combo, http://water.usgs.gov/lookup/getspatial?ds412_statewidelayers

P

 

P

P

P

RELIEF

Maximum - minimum elevation, in feet

ELEVMAX - MINBELEV

computed

BR

 

 

R

R

SLOP30

Percent of area with slopes greater than 30 percent. Computed from 10 m DEM and adjusted to approximate earlier values based on 30-m DEMs

0.5251*SLOP30_10M^1.1368

computed

S30

S30

S30

 

 

SLOP30_10M

Percent of area having slope greater than or equal to 30 percent, computed from 10-m DEM

percent of area

slop30, http://water.usgs.gov/lookup/getspatial?ds412_archydrohucs

 

 

 

 

 

SLOP50_30M

Percentage of area having slopes greater than 50 percent, computed from 30-meter DEMs

percent of area

slop50_30m http://water.usgs.gov/lookup/getspatial?ds412_archydrohucs

 

 

 

S50

S50

URBNLCD01

Percentage of urban land cover determined from NLCD 2001 land cover dataset

percent of area in  categories 21-24

NLCD 2001 Version 1.0  http://www.mrlc.gov/nlcd01_data.php

 

 

 

 

 

VOLCANIC

Percent of drainage area as surficial volcanic rocks as defined in SIR 2006-5035

percent of area

volcanics  http://water.usgs.gov/lookup/getspatial?ds412_archydrohucs

 

 

 

V

V

WAT_LU92

Percentage of area covered by water or perennial ice or snow from NLCD1992

percent of area

Enhanced NLCD 1992, http://water.usgs.gov/lookup/getspatial?nlcde92

 

 

 

W

W

The Idaho StreamStats introductory page here has additional information regarding the application, including links to reports, cooperators, and other explanatory information.