BOARD00284

• Board Meeting Date: 1/12/1971
• Description: Agenda or Table of Contents, Minutes, Memos
• Board Meetings - Doc Type: Meeting

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g~ound creW on this trip. We just happened to
be going over it. but you can see how much
easier it is to spot than in the previous
picture here where you can hardly see it in
the water at all. It immediately shows up a
bright red with color infrared film.

This is a very quick and economical
technique for surveillance of surface algae
and other aquatic growth in lakes and reser-
voirs.

When we saw this we were pretty sure what
it was. We asked the pilot to fly down lower,
went down downwind from it a little bit and
took this picture of a large algae bloom in
Lake Granby on about October 18, I think, of
1969.

This is another picture in straight color
of the inlet waters of Elevenmile Reservoir.
As you can see, you get various shades of
greens and grays and it becomes a little diffi-
cult to interpret what you are really seeing.
But in combination with straight color film
and then a color infrared shot, you can start
sorting out the living plant material and
that which is not. In the upper part of the
water body, a sort of pinkish area, these are
aquatic plants. Those which are nearer shore
are sub-aquatic protruding from the water.
The almost blackish looking spots that are
down in the bottom, which in the previous
picture you couldn't tell too much from the
shore, they are also aquatic but submerged
beneath the water. The attenuation of color
infrared is rather high.

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The different shades of light blue, from
white-grayish to light blue, are sediment
patterns. In the picture before you could
guess that but sometimes it is very hard to
tell sediment patterns from aquatic growth or
algae blooms. Here they become easily sepa-
rated.