WMOD00314

• Project Name: Uintah Ecology Project
• Title: Potential Ecological Impacts of Snowpack Augmentation in the Uintah Mountains, Utah
• Date: 4/20/1981
• State: UT
• Weather Modification - Doc Type: Report

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

21

Elevation (m)

Annual Precipitation (cm)

2,134 (7,000 ft)
2,438 (8,000 ft)
2,743 (9,000 ft)
3,048 (10,000 ft)
3,353 (11,000 ft)

54.4 (21.4 in)
62.0 (24.4 in)
69.6 (27.4 in)
77.2 (30.4 in)
84.8 (33.4 in)

Precipitation thus increases 7.6 ern per 305 m rise in elevation (3

in/lOOO ft). It should be noted that this model shows wide dispersion

around the regression line (r = .521). The regression is none-the-less

statistically significant at the .01 probability level.

.~~

The average relationship of water content in the April 1 snowpack

at various elevations is given in Table 2-1 and Figure 2-1. The data

demonstrate great variation from snow course-to-snow course in any given

altitudinal class (e.g., the snow course supporting the lightest average

snowpack on April 1 in the 2,438 - 2,743 m elevation class received only

about 12% as much snow as the course with the heaviest average snowpack

in that elevational zone). Nevertheless, when all snow courses within a

zone are averaged, there is a general trend toward increasing snowpack

with elevation (Figure 2-1). Arthough Figure 2-1 shows a sizeable

decline in snowpack at the highest elevation category, the sample con-

sists of only one snow course. When other snowcourses and years are

added to the analysis. the marked decline at the highest elevations is

largely eliminated. As might be expected. year-to-year variation in

average snowpack tends to be random among elevation classes. Year-to-

year variation apparently reflects broad synoptic patterns and is thus

quite uniform across the elevational gradient.