idea flow accumulation that can accomodate negative values in ArcGIS Pro Ideas https://community.esri.com/t5/arcgis-pro-ideas/flow-accumulation-that-can-accomodate-negative/idi-p/970472 <HTML><HEAD></HEAD><BODY>Currently flow accumulation in Spatial Analyst can only accomodate positive values - all negative values are treated as zero.&nbsp; I'd recommend creating an option (or a new tool) for flow accumulation for negative values (per <A href="http://forums.esri.com/Thread.asp?c=93&amp;f=995&amp;t=243378).&nbsp;">http://forums.esri.com/Thread.asp?c=93&amp;f=995&amp;t=243378).&nbsp;</A> Even better would be an option for accomodating flows of things like water that can start out positive but when they go negative they can't go less than zero.&nbsp; To my knowledge this hasn't been worked out by anyone in the ArcGIS community yet (see <A href="http://gis.stackexchange.com/questions/49462/how-can-i-get-weighted-flow-accumulation-to-deal-with-negative-values)">http://gis.stackexchange.com/questions/49462/how-can-i-get-weighted-flow-accumulation-to-deal-with-negative-values)</A> but it would be a tremendous resource for people who model flows of water but deal with weightings having to do with precipitation and evapotranspiration. <!-- content transformation source ID: 087E00000004Ydx --> </BODY></HTML> Tue, 12 Mar 2013 16:48:58 GMT ThomasDilts 2013-03-12T16:48:58Z flow accumulation that can accomodate negative values https://community.esri.com/t5/arcgis-pro-ideas/flow-accumulation-that-can-accomodate-negative/idi-p/970472 <HTML><HEAD></HEAD><BODY>Currently flow accumulation in Spatial Analyst can only accomodate positive values - all negative values are treated as zero.&nbsp; I'd recommend creating an option (or a new tool) for flow accumulation for negative values (per <A href="http://forums.esri.com/Thread.asp?c=93&amp;f=995&amp;t=243378).&nbsp;">http://forums.esri.com/Thread.asp?c=93&amp;f=995&amp;t=243378).&nbsp;</A> Even better would be an option for accomodating flows of things like water that can start out positive but when they go negative they can't go less than zero.&nbsp; To my knowledge this hasn't been worked out by anyone in the ArcGIS community yet (see <A href="http://gis.stackexchange.com/questions/49462/how-can-i-get-weighted-flow-accumulation-to-deal-with-negative-values)">http://gis.stackexchange.com/questions/49462/how-can-i-get-weighted-flow-accumulation-to-deal-with-negative-values)</A> but it would be a tremendous resource for people who model flows of water but deal with weightings having to do with precipitation and evapotranspiration. <!-- content transformation source ID: 087E00000004Ydx --> </BODY></HTML> Tue, 12 Mar 2013 16:48:58 GMT https://community.esri.com/t5/arcgis-pro-ideas/flow-accumulation-that-can-accomodate-negative/idi-p/970472 ThomasDilts 2013-03-12T16:48:58Z