How
CCWD uses Multi-Spectral Imaging to develop
each Landscape Water Budget
The
red photo (above) is the original multi-spectral
image shot from an airplane. This image is used
to identify individual properties (this is a
large office building in Concord with courtyards)
The yellow parcel polygon is drawn on this photo.
This green image (above) is derived from the
image at the top of the page. But the colors
identify landscape types. Brown is bare land
or bark, the black is "hardscape,"
such as streets and roof tops. The light green
is turf; dark green is shrubs and trees and
the blue is water. In this case, the water is
from backyard swimming pools.
The
top image is of Hidden Lakes Park in Martinez.
Below, you can clearly see the trees, turf and
bare areas.
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Multi-Spectral
Imaging
With
a grant from the United States Bureau of Reclamation,
CCWD set out to measure the landscape areas of each
of its 1,277 commercial, institutional and multifamily
dedicated irrigation accounts.
To
do this, the District uses aerial multi-spectral images.
The
images to the left provide estimates of landscape
area using a multiple-band digital camera system.
This
image is 'classified' into several key surface types
including: lawn, shrub/tree, water, bare soil, and
hardscape/roof.
Next,
parcel polygons were overlaid onto the image, producing
area measurements for each parcel. Using GIs software,
the image was linked to individual property parcels
and water account numbers.
Polygons
were then reviewed and adjustments made to ensure
accuracy of site boundaries.
The
final result is an image which displays individual
sites and square footage measurements for turf, non-turf
landscape, water features, bare soil, and hardscape.
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