am22

Gaps in thinned raster flowlines

Discussion created by am22 on Jun 2, 2012
I am working with raster NHD flowlines over a large spatial extent in ArcMap 10. In order to reduce processing time and allow a variety of calculations tied to a DEM, land use, etc., I am using the thin tool to reduce the flowlines to a width of one cell. For some reason, I am encountering gaps throughout the network, and these are preventing further analysis. After thinning, I made all non-flowline cells NoData, but subsequently discovered the gaps in the thinned flowlines. I haven't experienced this problem with coarser resolution data, and was wondering if that may be leading to the issues I am having. My extent is approximately 48,000 x 48,000 cells, with a cell size of 10m. Throughout the thinned stream network, there are approximately 800 gaps. My input settings for the thin tool (I've tried a few combinations) include a background value of Zero or NoData, no filter, round corners, and a range of maximum thicknesses of input linear features. Experimenting with the max thickness of input linear features has resulted in the relocation of gaps within the network, but they still remain unfortunately. I believe my environment settings are correct. I have been unable to find any discussion of similar issues related to this tool. Does anyone else have experience with this issue or know what might be leading to the errors and how to fix them?

Thanks!

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