topological_dangles

Creating a Depressionless DEM - Finding Sink Depth Problem

Discussion created by topological_dangles on Jan 21, 2012
Latest reply on Nov 22, 2017 by ihavinga
Hello,

My DEM (SRTM 90m) has sinks, as made clear by the output of the Flow Direction and Sink tools. I can fill these sinks with the Fill tool with no problem.

But I wanted to take a more precise approach by following the "Finding Sink Depth" process as outlined on the page, "Creating a Depressionless DEM". I followed each of the 5 steps outlined and determined that the maximum sink depth was 33 meters, as the output of the Minus tool ranged from 1 to 33.

I ran the Fill tool on the original DEM and specified a z-limit of 33 and then ran Flow Direction on this output. The Flow Direction output was the same as the Flow Direction output from the original, un-filled DEM. In other words, the "Finding Sink Depth" approach didn't work, unless I missed a step or made a mistake somewhere in there.

Anyone encounter a similar problem? Any thoughts or guidance would be most welcome.

Thanks.

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