WSP09472

• File Number: 8101
• Description: Arkansas River Basin Description
• State: CO
• Basin: Arkansas
• Water Division: 2
• Date: 12/1/1948
• Author: Corps of Engineers
• Title: Drainage Area Data - Arkansas White and Red River Basins
• Water Supply Pro - Doc Type: Report/Study

OUTLINlJ; OF PROCEDURE FOR DETERMINATION OF
WRm RlVER BASIN DRAINAGE AREAS

I. Establishment of watershed boundaries.

,
a. Tentative watershed boundaries were sketohed on Corps of Engineers and .j
Department of Agrioulture photographio indexes by inepection and by
reference to the best available maps. Reference was made to the White
River Valley Survey, Cotter to Batesvllle, Arkansas, and to s:llll1lar
Corps of Engineers I maps of reservoir areas, as well as to the Mississippi
River COJlIIIlission quadrangles, U.S.G.S. quadrangle maps, and county maps.

b. Full size aerial photographs covering the tentatiVe watershed boundary
were examined stereosoopically to determine the definite location of the
boundary .

c. Concurrent~ with the stereoscopic examination, the tentative watershed
boundary previous~ sketched on the mosdo index was adJusted as re-
quired to represent the final watershed,boundary.

2 . Breakdown of Areas.

.

Watersheds were determined, as indicated in pare.graph 1 above, for
the main stem 01' the White River, from its mouth to its source, and
for major and ll11nortributaries and their tributaries or subareas
for dam sites, ge.ging stations, etc.

3. Determination of Drainage Areas.

a. Quadrilaterale 01' l-ll11nute latitude and longitude were plotted on the
aerial mosaic along the previously determined watershed boundaries.

b . Base maps, each oonsisting of a 60 by 6o-ll11uute projection were pre-
pared 1'01' transfer of watershed boundaries 1'rom the aerial mosaic.
The projections, scale IIJ25 ,000, were divided into 5-ll11nute quadri-
laterals and further subdivided into l-l!1inute quadrilaterals.

c. The l:llll1ting boundaries of all drainage areas and subareas were trans-
ferred from the aerial lDflsaics to the ll125,OOO base maps in prepara-
tion for the cOIIqlutation of drainage area values.

d. Values of each l-ll11uute quadrilateral were determined; mathelDll.tically
by referenoe to published tables of latitude and longitude values.
Along waterehed boundaries thepercentege of a quadrilateral within
a particular drainage area was determined by use of' a planimeter.
This percentage applied against the mathematioal value of the eutire
quadrilateral furnished the desired figure for use in cOIIqlilatiou of
the over-all value for the area or subarea.

D