Showing boulder on Topo map

[sako]

This is first time I do a topo on a property with several boulders (10'X10') on it. I was wondering if I need to show the perimeter only, or take shots to top, show the contour lines and boulders as a topographic feature.

[LS 4722]

Outline the perimeter and label it with an approx size. What city is this in? I did one of these types way back in the early 70's. Mine was in Chatsworth and the lot had huge sandstone boulders. We just did an outline and notes. The topo just showed the ground surface.

[pls7809]

I agree with Paul. I would not contour the boulders as part of the ground surface. Part of the problem with that is if the boulder is sitting on top of the ground then there may be areas where contours will cross or overlap, which never works really well with DTM software.

[Jim Frame]

Same as Paul -- I show boulders as features upon the ground, not part of the ground, so outline and notation but no contours. I might put a spot elevation on it if it seemed appropriate.

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[LS_8750]

Depends. If it is a geologic feature, i.e. the ground surface, then topo it. Otherwise it's a judgement call.

[sako]

Thank you guys, these boulders sit on top of ground, not part of it, so I guess I would only show the perimeter with the size of boulder.

[coast]

I would say it depends on what the topo is going to be used for. An architect could want to incorporate them in his building or landscape design. They may want elevation data on boulders to determine amount of rock for some reason, say break apart boulders and then crush to be used as roadway surface.

Can't hurt to ask.