The figures are depth of cables and pipes for gas, water, communication cables etc. I get a quikscan of cables representing the location in 2D and depth in m, but the dept can vary between 0,00 and 2,50 m, where each cable may vary in depth in it's path in relation to the terrain. I think that a delta terrainmodel is possible, only when a lot of cables/pipes are located at the same depth
The picture with depthfigures I made up to clarify.
The picture with depthfigures I made up to clarify.