Surface Range 2d Area

[wings1080]

can someone please give me a definition of what exactly this is?  i just created a table but need to know what the numbers mean and googling is useless, see attached table, for speaking purposes, number 5 which is 43' to 44', what is the 12,164.09 area????

[neilyj666 · Accepted solution]

My understanding of these areas is that if you imagine a series of concentric circles the lowest value i.e.Number 1 represents the smallest circle. Number 2 represents the annular area between circle 1 and 2, Number 3 is the annular area between 2 and 3 etc.

Thus the area for Number 5 only represents the area between 44' and 45' (so for say a flood level of 45' the area flooded would be the sum of the areas 1 to 5) and the total of all the areas should equal the total surface area (2D)

[wings1080]

cool, thanks ... are you sure this is right? would like one more person to chime in on this unless you are sure

also, the topography is definitely not uniform as you describe in your example, there will be tiny little islands, 100's of them between certain elevation ranges, I am hoping it accounts for this, no idea how this could be be computed but i have faith in the great god of civil 3d

[neilyj666]

my example was just that to illustrate the concept. I'm pretty sure that all the little islands are accounted for- check the total adds up to the surface area. You could extract user contours and calculate the area between them.

[conormccartney3897]

Yup Neilyj is right, for your particluar example, the area for number 5 is everything in your surface between elevations 43 and 44.

[wings1080]

thanks guys