This tool provides an alternative method for calculating a flow accumulation grid (i.e. contributing area) using the FD8 algorithm (Freeman, 1991). It uses an efficient stack-based method. For more details on the FD8 method please see FD8 Flow Accumulation. Please note that the output raster gives the number of upslope cells. Flow dispersion ceases for grid cells with upslope areas greater than the flow convergence threshold.
The following is an example of a Python script that uses this tool:
wd = pluginHost.getWorkingDirectory()
demFile = wd + "DEM.dep"
outputFile = wd + "output.dep"
exponent = "1.0"
threshold = "1000"
args = [demFile, outputFile, exponent, threshold]
pluginHost.runPlugin("FlowAccumFD82", args, False)
This is a Groovy script also using this tool:
def wd = pluginHost.getWorkingDirectory()
def demFile = wd + "DEM.dep"
def outputFile = wd + "output.dep"
def exponent = "1.0"
def threshold = "not specified"
String[] args = [demFile, outputFile, exponent, threshold]
pluginHost.runPlugin("FlowAccumFD82", args, false)