topic Unweighted Flow Accumulation issue in ArcGIS Spatial Analyst Questions https://community.esri.com/t5/arcgis-spatial-analyst-questions/unweighted-flow-accumulation-issue/m-p/408000#M5728 <HTML><HEAD></HEAD><BODY><SPAN>I have to get a flow accumulation to creat river network, using&nbsp; raletive low resolution(90M) SRTM data. I have mosaiced 13 SRTM to creat a new raster.Then I created no-lowland flow direction raster, then I wanted to creat unweighted flow accumulation using the no-lowland flow direction raster. I&nbsp; have made sure that the data is in the same coordinate system at the same resolution and the pixels are perfectly aligned. However, when I run it, it just says "Updating Flow Accumulation" for hours. I have run it overnight and it has not changed.So,what can I do to solve the issue??</SPAN></BODY></HTML> Sun, 05 Jun 2011 11:56:52 GMT RobertLiu 2011-06-05T11:56:52Z Unweighted Flow Accumulation issue https://community.esri.com/t5/arcgis-spatial-analyst-questions/unweighted-flow-accumulation-issue/m-p/408000#M5728 <HTML><HEAD></HEAD><BODY><SPAN>I have to get a flow accumulation to creat river network, using&nbsp; raletive low resolution(90M) SRTM data. I have mosaiced 13 SRTM to creat a new raster.Then I created no-lowland flow direction raster, then I wanted to creat unweighted flow accumulation using the no-lowland flow direction raster. I&nbsp; have made sure that the data is in the same coordinate system at the same resolution and the pixels are perfectly aligned. However, when I run it, it just says "Updating Flow Accumulation" for hours. I have run it overnight and it has not changed.So,what can I do to solve the issue??</SPAN></BODY></HTML> Sun, 05 Jun 2011 11:56:52 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/unweighted-flow-accumulation-issue/m-p/408000#M5728 RobertLiu 2011-06-05T11:56:52Z