Gradational Approach to Contouring? 1

[flyfisher42]

All,

Here I'am with no text (its at home), just a computer to determine how to contour using the gradational approach.

If I recall correctly you determine the distance between to known points of elevation and then divide by the number of contour intervals between the two known points. That number would then be the distance between the coutour intervals between the known points.

Does that sound correct?

Thanks for any advice,

 

[RWF7437]

Doesn't sound corect.

Take the following example:

Point A Known elevation = 123.45 ft
Point B Known elevation = 138.67 ft

Elev. Difference = 138.67-123.45 = 15.22 ft

Distance from A to B = 100 feet
Slope between A and B = (15.22 ft / 100 ft) = .1522 ft per foot

If your contour interval is 2 feet then the distance from Point B to the 138' contour is = (138.27-138.00)/0.1522 = 1.77 feet

And the distance between the 138' contour and the 136' contour is = 2ft/.1522 ft/ft = 13.14 feet and so on.......

good luck

 

[flyfisher42]

Thanks for the wake up call RWF,

Still not quite sure what I was thinking on Friday.....

 

[queque]

138.67 - 138 = 0.67

0.67/.1522 = 4.4 ft.