topic Re: Raster creation for cut/fill in Geoprocessing Questions

Raster creation for cut/fill

BobMCkay — Wed, 05 Oct 2016 21:47:34 GMT

Hi,

Arcmap raster creation for cut/fill operation.

We have a irrigation channel that we plan to pipe. We need to use the cut/fill tool to show us the volumes of soil needed to be moved.

We have a DEM of the area. I need to create another raster to use with the current DEM. The new raster will follow the natural surface along the pipeline. i.e. The surface after the pipe is laid and the channel filled in.

The attached image shows cross section lines every 50m down the pipeline. The elevation at the ends of each cross section will somehow be used in the new raster. The new raster elevations along each cross section will be interpolated in a straight line between the end points.

How can a raster be produced that mimics a natural surface along the pipeline?

Cheers

Bob

Re: Raster creation for cut/fill

DanPatterson_Retired — Wed, 05 Oct 2016 22:18:34 GMT

just a quick thought... could you not just create a polygon from the points, extract the dem from within it, subtract 50 cm from the result. That should give you the bottom at least

Re: Raster creation for cut/fill

BobMCkay — Thu, 06 Oct 2016 03:02:24 GMT

Hi Dan,

I'm new at this raster creation thingy but wouldn't creating a polygon and than a raster 50cm below would mirror the same values in the DEM, just 50 cm lower?

Re: Raster creation for cut/fill

DanPatterson_Retired — Thu, 06 Oct 2016 03:08:38 GMT

so you want them along the transect lines? or normal to them?

Re: Raster creation for cut/fill

BobMCkay — Thu, 06 Oct 2016 03:38:28 GMT

Along each transect, line each cell value, will increase/decrease linearly using the two end point elevations..

In between transect lines, each cell value, will increase/decrease linearly using the corresponding value in the adjacent line.

The shape of the resulting raster, in 3D, would resemble a ribbon with no folds or bends across it, but wavy in appearance.

Re: Raster creation for cut/fill

DanPatterson_Retired — Thu, 06 Oct 2016 04:18:44 GMT

I see where you are going now... I got stuck with the picture in my mind of the shovel operator trying to dig to match specs.