As part of a National Park Service/U.S. Geological Survey inter-
agency agreement, hydrologic characteristics are being determined
for rivers and streams located in National Parks of Alaska. Many of
these characteristics will be determined by use of Geographical
Information System (GIS) techniques. All GIS coverages that have
been created are available to other interested parties.
This data set will provide the National Park Service with information needed to do basic spatial analysis for a specific watershed. For example, a basin boundary digitized and entered into a Geographic Information System (GIS) can be used in overlay operations with a statewide precipitation coverage to determine the amount of precipitation for the basin. In turn, these hydrologic characteristics can then be used as input to hydrologic runoff models or regression equations to estimate peak flows or annual flows of a particular river or stream. The data set will be also be added to the USGS, Alaska District's, statewide data base of basin characteristics for rivers and streams of Alaska.
Procedures_Used Drainage basin boundaries for the Tlikakila River were delineated on USGS 1:63,360 scale topographic maps. The boundaries on each quadrangle were then digitized using ARC/INFO software on an Altek 9000 digitizer or a Calcomp Drawing Board III digitizer. Weed tolerances were set at 0.001 and snapping tolerances were set at 0.005. During registration, RMS erros > 0.005 were not accepted
Once digitized, the arcs from each quadrangle were projected into an Albers Equal Area projection with the following parameters:
Projection ALBERS Units Meters Spheroid CLARKE1866 Datum NAD27 Parameters: 1st standard parallel 55 00 00 2nd standard parallel 65 00 00 central meridian -154 00 00 latitude of projection's origin 50 00 00 false easting (meters) 0.0000 false northing (meters) 0.0000
Arcs were then appended and overshoots & undershoots were corrected. Polygon topology was then created and labels added.
TLIK_DA.PAT: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME 1 AREA 8 18 F 5 9 PERIMETER 8 18 F 5 17 TLIK_DA# 4 5 B - 21 TLIK_DA-ID 4 5 B - TLIK_DA.AAT: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME 1 FNODE# 4 5 B - 5 TNODE# 4 5 B - 9 LPOLY# 4 5 B - 13 RPOLY# 4 5 B - 17 LENGTH 8 18 F 5 25 TLIK_DA# 4 5 B - 29 TLIK_DA-ID 4 5 B -
Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data.
The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials.