Author Question: Examine the photo of Glen Canyon Dam in Arizona and the reservoir called Lake Powell that formed ... (Read 57 times)

LCritchfi · **on:** Jul 14, 2018

Examine the photo of Glen Canyon Dam in Arizona and the reservoir called Lake Powell that formed upstream of it.

Describe what has happened to the base level on the Colorado River at this location since the dam was constructed. Make a prediction for what will happen at this location over the next several hundred years.
What will be an ideal response?

Question 2

The Persian Gulf states provide more than 80 percent of Japan's oil.

Indicate whether the statement is true or false

kthug · **Reply #1 on:** Jul 14, 2018

Answer to Question 1

Answer: Glen Canyon Dam imposed a new local base level on the Colorado River at this location. As a result, the river upstream lost velocity, and shifted from being in the Zone of Erosion (Zone of Sediment Production) or the Zone of Transport to being in a new, temporary Zone of Deposition. Still waters of Lake Powell deposited their bed load and suspended load, filling in some of the space at the bottom of Lake Powell. Answers to the second part (predictions for the future) will vary, but one possibility is this: Without preventive maintenance, this massive sediment trap could eventually be filled with silt, and the waters of the Colorado River might overtop Glen Canyon Dam, creating a new waterfall. If the waterfall breaches the dam, then the river will relatively rapidly erode all of the new lake deposits and re-reveal Glen Canyon.

Answer to Question 2

TRUE