ASC to ASC: Difference between revisions
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Two .asc grids are output:
*The first is the difference values between the two .asc files. A difference value only occurs at grid cells that have a value in both grids. If the cell has a null value (ie. the TUFLOW output was dry at that location) in either or both .asc grids, a null value is output.
*A second grid with a “_wd” suffix is output to indicate which .asc grid cells were once wet and are now dry (value -99) or once dry and are now wet (value +99 with first .asc to be the developed case and second .asc to be the existing case). Importing this grid into Vertical Mapper creates a .grc (grid classification) grid that has two categories: “Was Wet Now Dry” and “Was Dry Now Wet”. This grid is particularly useful for displaying areas that were previously inundated or previously flood-free.
<li><tt>asc_to_asc.exe -out difference.asc -dif after_h.asc before_h.asc</tt><br>
Creates new grids comparing the differences in flood levels and extents for: "difference.asc" = "after_h.asc" - "before_h.asc"</li>
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