contours and area calcs between contour lines

[jleftwich]

I am trying to create contour lines from polylines for mineral geologicalmapping. Can I even do this or is there something more complex I have to do. I have another question how can I find the area between these two contour lines (polylines). I appreciate any help.


I need someone to help me walk through the steps. Thank you

[cadman009]

don't know if you still need help with this. if you're talking about getting 2d areas i can help. if you're talking 3d i can't because i've never tried it. in 2d, you will probably want to create a polygon topology from the contours to be able to extract areas.

[jleftwich]

it is in 2d. How do I make polygon topologies. thanks

[cadman009]

ok. definitely try to use the tutorial for polygon topologies. it will walk you through the process. first thing you need to do is to make sure you have clean geometry to work with. make a copy of the drawing you're starting with so you can go back to it, isolate the contour layers and whatever boundary you're going to (property line?), then use the map cleanup tools to clean it up. i set all the tolerances to 1.0 and run all the cleanup tools at once. it usually takes about 3 passes in this manner to clean up everything. one thing to keep in mind is that with map 2004 (i don't know about 2005) you can't use splines for your polygon edges. if they are splined polylines you can explode them before you clean up. the clean-up will re-join the pieces into polylines. you have to have an enclosed area for each polygon in order to be able to create a topology. any gaps larger than 1.0 unit will have to be joined manually. if you have a bunch of gaps, and you can afford a bigger tolerance you can increase your cleanup tolerances, but that's up to you. that's how you start. check the help and tutorials for creating the polygon topology and also to query your areas to a report. holler if you need further help.