topic Multiple flow direction calculation in ArcGIS (more the D8) - possible and why? in Water Resources Questions https://community.esri.com/t5/water-resources-questions/multiple-flow-direction-calculation-in-arcgis-more/m-p/4830#M18 <HTML><HEAD></HEAD><BODY><SPAN>I have started reading more about flow calculation - and realised that there are two major ways of calculation the flow direction - or distribute the flow: </SPAN><BR /><SPAN>A) The Standard Flow Direction: Choosing the neighboring cell with the lowest value from the DEM, compared to the value of the calculated cell - and distribute all "upstream area" to this single cell. </SPAN><BR /><SPAN>B) The Multiple Flow Direction: Choosing all the neighboring cells with values lower than the calculated cell and distribute "upstream area" to all these cells.&nbsp; </SPAN><BR /><BR /><SPAN>The best illustration of this was found in the GRASS documentation: </SPAN><A href="http://grass.osgeo.org/grass64/manuals/r.terraflow.html">http://grass.osgeo.org/grass64/manuals/r.terraflow.html</A><BR /><BR /><SPAN>Now, my questions are: </SPAN><BR /><SPAN>1) Is it possible to try this Multiple Flow Direction calculation in ArcGIS, or using some kind of other extensions?</SPAN><BR /><SPAN>2) What it the point of calculating this Multiple Flow Direction? When do we need this way of calculating flow-directions and why is this not a part of the "standard" tools in ArcGIS and its extensions?</SPAN><BR /><BR /><SPAN>Hoping that somebody can explain this to me...:)</SPAN></BODY></HTML> Tue, 26 Mar 2013 14:15:16 GMT MartinJespersen 2013-03-26T14:15:16Z Multiple flow direction calculation in ArcGIS (more the D8) - possible and why? https://community.esri.com/t5/water-resources-questions/multiple-flow-direction-calculation-in-arcgis-more/m-p/4830#M18 <HTML><HEAD></HEAD><BODY><SPAN>I have started reading more about flow calculation - and realised that there are two major ways of calculation the flow direction - or distribute the flow: </SPAN><BR /><SPAN>A) The Standard Flow Direction: Choosing the neighboring cell with the lowest value from the DEM, compared to the value of the calculated cell - and distribute all "upstream area" to this single cell. </SPAN><BR /><SPAN>B) The Multiple Flow Direction: Choosing all the neighboring cells with values lower than the calculated cell and distribute "upstream area" to all these cells.&nbsp; </SPAN><BR /><BR /><SPAN>The best illustration of this was found in the GRASS documentation: </SPAN><A href="http://grass.osgeo.org/grass64/manuals/r.terraflow.html">http://grass.osgeo.org/grass64/manuals/r.terraflow.html</A><BR /><BR /><SPAN>Now, my questions are: </SPAN><BR /><SPAN>1) Is it possible to try this Multiple Flow Direction calculation in ArcGIS, or using some kind of other extensions?</SPAN><BR /><SPAN>2) What it the point of calculating this Multiple Flow Direction? When do we need this way of calculating flow-directions and why is this not a part of the "standard" tools in ArcGIS and its extensions?</SPAN><BR /><BR /><SPAN>Hoping that somebody can explain this to me...:)</SPAN></BODY></HTML> Tue, 26 Mar 2013 14:15:16 GMT https://community.esri.com/t5/water-resources-questions/multiple-flow-direction-calculation-in-arcgis-more/m-p/4830#M18 MartinJespersen 2013-03-26T14:15:16Z