00:01In this case, we'll use 3D Analyst to calculate the volume of the soil type that needs to be...

00:05...removed for the RandstadRail Subway tunnel seen here in red.

00:09We'll use the geotop model developed by TNR in Holland, which is a 3D logical model...

00:14...of the upper 30 meters of the subsurface.

00:18The model consists of 3D grid cells, each 100 by 100 by 0.5 meters with attributes...

00:23...describing the soil.

00:25In here, we have closed multi-patches classified by soil type, which we generated...

00:30...from these raw geotop data points that you can see here.

00:34Now what we want to do next is we want to create a 3D buffer around a tunnel...

00:39...centerline and then use this closed multi-patch to then select, in 3D space...

00:44...the geotop grid cells that intersect with the tunnel.

00:53And then, we can perform the actual intersect in 3D...

00:57...to get the salt up volumes inside our subway tunnel.

01:04Or, alternatively, we can subtract the tunnel from the geotop grid cells...

01:09...to see the different soil types inside the tunnel as we fly through it.

01:18And the end result that we're after is we want to summarize by soil type to get a good...

01:23...indication of how much of each soil type needs to be removed.

01:27And as you can see here in the graph...

01:29...peat is the largest volume followed by clay and then sand.

01:34And for more information on 3D GIS and other use cases...

01:38...please keep exploring our 3D GIS Resource Center.