> Harding's 1400-year synthetic stream trace of inflow to Lake Powell
> generated, as he noted, a value of 60 - 70 MAF as the 1400 year event.
Well, just to stem another internet myth...
This was a statistical exercise. We did not hypothesize a
physical basis for the flow. Here are some facts you can use to
evaluate our work:
The CR basin encompasses 250k square miles or 160,000,000 acres.
The upper basin encompasses roughly 44% of this. On this basis,
our estimate indicates roughly one foot of _runoff_ in the upper
basin compared to 2 inches based on the historical average.
Now, what about its return interval? Our statistics indicated
1400 years. But, if that were true, we would expect to see
evidence of several 800k cfs flows in the canyon with sufficient
organic material buried under them to allow for carbon dating.
Is there any evidence of this?
So, is it possible. Decide for yourself. In my mind, it's
definitely not impossible, but it might not play out like a
normal year. For example, it might be the result of a very wet
fall followed by extraordinary snows and then an extraordinarily
wet summer. This would imply a flatter hydrograph and thus
lower peak flows than estimate by Perry. In any case, it would
be an _extreme_ event, probably rarer than a 1400-year return
interval.
Ben
-- -------------------------------------------------- -- Ben Harding blh@hydrosphere.com -- -- Hydrosphere Resource Consultants -- -- Hydrosphere Data Products -- -- 1002 Walnut, Suite 200 -- -- Boulder CO 80302 -- -- -- -- 303-443-7839 voice 303-442-0616 fax -- -- -- -- Publishing Natural Resources Data on CD ROM -- -- Consultants in Natural Resources Planning -- -------------------------------------------------- ==================================================================== To subscribe, send email to majordomo@songbird.com, with "subscribe gcboaters" as the only line in the message body. To unsubscribe send "unsubscribe gcboaters". For further information send "info gcboaters", or see http://www.songbird.com/gcboaters ====================================================================