topic Flow Length ??? Understanding Output Raster in ArcGIS Spatial Analyst Questions https://community.esri.com/t5/arcgis-spatial-analyst-questions/flow-length-understanding-output-raster/m-p/329074#M4619 <HTML><HEAD></HEAD><BODY><SPAN>I need the length of the longest flow path within a watershed.&nbsp; I???ve established the watershed and used the ???Flow Length??? tool with the ???upstream??? option on a Flow Direction grid.&nbsp; I???m expecting the raster pixel at the outlet point to have a value that matches the length of the longest flow path ??? but that does not appear to be the case.&nbsp; Can anybody share what I might have done wrong, or what I need to do from here?</SPAN><BR /><BR /><SPAN>Thank You,</SPAN><BR /><SPAN>Jim</SPAN></BODY></HTML> Fri, 23 Apr 2010 18:29:31 GMT JamesKelly 2010-04-23T18:29:31Z Flow Length ??? Understanding Output Raster https://community.esri.com/t5/arcgis-spatial-analyst-questions/flow-length-understanding-output-raster/m-p/329074#M4619 <HTML><HEAD></HEAD><BODY><SPAN>I need the length of the longest flow path within a watershed.&nbsp; I???ve established the watershed and used the ???Flow Length??? tool with the ???upstream??? option on a Flow Direction grid.&nbsp; I???m expecting the raster pixel at the outlet point to have a value that matches the length of the longest flow path ??? but that does not appear to be the case.&nbsp; Can anybody share what I might have done wrong, or what I need to do from here?</SPAN><BR /><BR /><SPAN>Thank You,</SPAN><BR /><SPAN>Jim</SPAN></BODY></HTML> Fri, 23 Apr 2010 18:29:31 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/flow-length-understanding-output-raster/m-p/329074#M4619 JamesKelly 2010-04-23T18:29:31Z Re: Flow Length �?? Understanding Output Raster https://community.esri.com/t5/arcgis-spatial-analyst-questions/flow-length-understanding-output-raster/m-p/329075#M4620 <HTML><HEAD></HEAD><BODY><SPAN>The longest flow path function is part of ArcHydro. It is free. May take a little while to learn it though.</SPAN></BODY></HTML> Wed, 27 Apr 2011 19:29:47 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/flow-length-understanding-output-raster/m-p/329075#M4620 MarkBoucher 2011-04-27T19:29:47Z