The new Diamond Valley Lake Reservoir near the city of Hemet in Riverside
County is billed as the largest earthworks construction project in U.S.
history. Construction began in 1995 and involved 31 million cubic meters of
foundation excavation and 84 million cubic meters of embankment
construction. This set of MISR images captures the most recent phase
in the reservoir's activation. At the upper left is a natural-color view
acquired by the instrument's vertical-viewing (nadir)
camera on March 14, 2000 (Terra orbit 1273), shortly after the Metropolitan
Water District began filling the reservoir with water from the Colorado
River and Northern California. Water appears darker than the surrounding
land. The image at the upper right was acquired nearly one year later on
March 1, 2001 (Terra orbit 6399), and shows a clear increase in the
reservoir's water content. When full, the lake will hold nearly a trillion
liters of water.
According to the Metropolitan Water District, the 7 kilometer x 3 kilometer
reservoir nearly doubles Southern California's above-ground
water storage capacity. In addition to routine water management, Diamond
Valley Lake is designed to provide protection against drought and a
six-month emergency supply in the event of earthquake damage to a major
aqueduct. In the face of electrical power shortages, it is also expected to
reduce dependence on the pumping of water from northern mountains during
the high-demand summer months. An unexpected result of site excavation was
the uncovering of mastodon and mammoth skeletons along with bones from
extinct species not previously thought to have been indigenous to the area,
such as the giant long-horned bison and North American lion. A museum and
interpretive center is being built to protect these finds.
The lower MISR image, from May 20, 2001 (Terra orbit 7564), is a
false-color view combining data from the instrument's 26-degree forward
view (displayed as blue) with data from the 26-degree backward view
(displayed as yellow). This technique enables bodies of water to stand
out prominently by taking advantage of the strong change
in brightness between the two view angles and the contrasting angular
signature of the surrounding land. The blue-yellow separation in the cloud
field is due to geometric parallax resulting from the clouds' elevation
above the surface terrain.
Each image covers an area measuring approximately 125 kilometers x 95
kilometers. The northwest to southeast trending linear feature is the
Elsinore Fault.
Image credit: NASA/GSFC/LaRC/JPL, MISR Team.
|
