QUICK REFERENCE
Drainage Basins
Roads: Identification Information
Originator: EROS Data Center
Date: unknown
Title: HYDRO 1K
Elevation Derivative Database
Purpose: The
Hydro1k Drainage Basins are a general purpose global database designed to
support
Geographic Information Systems
applications.
Abstract: The drainage basins distributed with the
HYDRO1k data set suite are derived using the vector stream networks along with
the flow direction data set. Each polygon in the basin data set has been tagged
with a Pfafstetter code uniquely identifying each sub-basin. A detailed
description of the coding scheme can be found in Verdin. Additional attributes defining the characteristics of each
sub-basin have been developed. These are described in the Readme file. These data are available in an ARC/INFO
export format..
Access Constraints: none
Use Constraints: none
Ordering
Instructions: Datasets are available from the web page
below.
Contact
Address: 47914 252nd Street.
City:
Sioux Falls
State
or Province: SD
Postal Code:
57198-0001
Country:
USA
Online Linkage: http://edcdaac.usgs.gov/gtopo30/hydro/
Entity and Attribute
Information (table heading explanations)
Shape: ArcView file
type
Area:
Area of polygon (m2)
Perimeter:
Perimeter of polygon (m)
Level1
to Level6: Pfafstetter units of each polygon
Slope_mean:
Mean value of the slopes within the subbasin (degree)
Slope_stdev:
Standard deviation of the slopes within the subbasin (degree)
Aspect_mean:
Mean value of the aspects within the subbasin (degree from N)
Aspect_stdev:
Standard deviation of the aspects within the subbasin (degree from N)
Dem_mean:
Mean elevation value within the subbasin (m)
Dem_stdev:
Standard deviation of the elevations within the subbasin (m)
Cti_mean:
unknown
Cti_stdev:
unknown
Global GIS Note:
To help with space the polygons were generalized to reduce file size. The polygons were generalized with a factor
of 0.007 degrees, which would allow shifts less than one kilometer at the
equator. But in general there was not a noticeable difference.