https://community.esri.com/t5/water-resources-questions/how-to-classify-a-dem-base-on-the-lowest-elevation/m-p/1023267#M4004 <P>How to classify a DEM base on the lowest elevation of a stream (stream generated by flow accumulation of same DEM)? Or should I say, I want to find those elevation of DEM that are close to the floor of the stream. It's not a simple classification because the stream floor does not have same elevations in its whole lenght, meaning that there is a big elevation difference between start and end point of stream (Stream has alot of slope!) Any solution please... Thanks And sorry for my poor English❤</P> Thu, 04 Feb 2021 02:22:24 GMT JalilGhaznawi 2021-02-04T02:22:24Z https://community.esri.com/t5/water-resources-questions/how-to-classify-a-dem-base-on-the-lowest-elevation/m-p/1023267#M4004 <P>How to classify a DEM base on the lowest elevation of a stream (stream generated by flow accumulation of same DEM)? Or should I say, I want to find those elevation of DEM that are close to the floor of the stream. It's not a simple classification because the stream floor does not have same elevations in its whole lenght, meaning that there is a big elevation difference between start and end point of stream (Stream has alot of slope!) Any solution please... Thanks And sorry for my poor English❤</P> Thu, 04 Feb 2021 02:22:24 GMT https://community.esri.com/t5/water-resources-questions/how-to-classify-a-dem-base-on-the-lowest-elevation/m-p/1023267#M4004 JalilGhaznawi 2021-02-04T02:22:24Z https://community.esri.com/t5/water-resources-questions/how-to-classify-a-dem-base-on-the-lowest-elevation/m-p/1023316#M4005 <P>I think you might be referring to the HAND (height above nearest drainage) concept (if you search this topic, you will find a lot of good references).</P><P>The tool that allows you to derive HAND surface based on preprocesed DEM (you will need: DEM, flow direction, and stream rasters) is the "Flow Distance" Spatial Analyst tool.&nbsp; Use "Vertical" as the "Distance Type" in the user interface.</P><P>This function generates for cell in the raster a difference between the value at that cell and the value of the cell in the river "nearest" to the cell - thus "height above nearest drainage".&nbsp; Review the function help - there are several options and the choice might depend on the type of analysis you are going to do with that surface.</P> Thu, 04 Feb 2021 08:50:19 GMT https://community.esri.com/t5/water-resources-questions/how-to-classify-a-dem-base-on-the-lowest-elevation/m-p/1023316#M4005 DeanDjokic 2021-02-04T08:50:19Z