Unweighted Flow Accumulation issue

Discussion created by fengzhiyan20 on Jun 5, 2011
I have to get a flow accumulation to creat river network, using  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  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??