Hello,
I am trying to estimate the area of irregular polygons drawn on graph paper
with a known scale.
I currently have 50 sheets of graph paper (one each for my 50 sites) with hand
drawn maps indicating different substrates, centered on a focal point. The side
of each square in the graph is 5m. I would like to draw concentric circles
around the focal point (15m, 30m, 45m etc) and estimate the area under each
circle/annulus that falls within one polygon (substrate) or the other.
Is there any simple graphing/blueprint software which can take scanned graph
paper with a known scale and generate estimates of area? Could I possibly do
this in Arcview 3.2 without importing any UTM data? Essentially, I would like
to look at a map and say: The area of short grass within the 1st concentric
circle (0-15m) is 400 m sq. and the rest is bare ground, etc.
I understand that my alternate solution is to physically count graph squares
within each polygon and estimate the number of partial squares, but I would
like to be as accurate as possible. Further, making that same estimate
repeatedly would generate a different area each time.
Thanks for your suggestions,
Aaftab Jain
Contract Biologist.
Albuquerque, NM.
****************** aaft...@hotmail.com *******************
