Quadtree and Sub-Grid Sampling FAQ: Difference between revisions

The reason for this is that SGS doesn't know where in the cell the low elevations and high elevations are, so it smooths out the breaklines. It allows water to flow from low point to low point within the same cell even if there is higher point in between them.

 

SGS isn't a silver bullet that resolves all. If the hydraulic controls aren't adequately defined by the chosen cell resolution the results will vary until the said features are defined by the mesh adequately. Check the gully lines and ridge lines questions above. For a situation where there is little variation in velocity across channel the results might be impressive. In the real world, where there are significant velocity gradients across the channel the modeller might need to use a finer resolution to converge to a solution.