topic Re: Line artifacts in flood depth raster (Flood from Stream WSE) in Water Resources Questions

Line artifacts in flood depth raster (Flood from Stream WSE)

JessicaKlassen — Wed, 23 May 2018 16:08:31 GMT

I'm trying to create a flooding depth raster by using the "Stream WSE from point WSE Measurements" and "Flood from Stream WSE" as in (https://blogs.esri.com/esri/arcgis/2014/03/17/floodplain-delineation-using-only-arc-hydro-models). However, my output flood depth raster has line artifacts/abrupt changes in flooding depth that to not make sense given the underlying DEM is smooth in these locations. See the attached picture for an example, I'm using Lidar data for my DEM.

Any ideas on what would be causing these line artifacts? Thanks!

Re: Line artifacts in flood depth raster (Flood from Stream WSE)

MarkBoucher — Wed, 23 May 2018 19:05:55 GMT

Similar question here: https://community.esri.com/thread/110326

Re: Line artifacts in flood depth raster (Flood from Stream WSE)

MarkBoucher — Mon, 04 Jun 2018 16:20:53 GMT

I recently experienced this. I was creating a DEM from LiDAR (LAS files).

I found that I had the DEM grid size different in the settings of a couple of geoprocessing tools. I had one process using 1' DEM and another using 2'. Had very strange patterns. Once I discovered my error, made the correction, and the phantom lines when away.

Re: Line artifacts in flood depth raster (Flood from Stream WSE)

EdCarter — Mon, 20 Dec 2021 16:22:09 GMT

We are having the same trouble. Is there a way to put breaklines in or reinforce the DEM so values are interpolated from the appropriate source? In our case it is interpolating over ridges in the DEM, sometimes just partially.