Star Hydro analysis starts with loading of terrain maps.
Layers required to perform analysis are:
Pit filled terrain
Flow direction (D8)
Star Hydro at this time (7/9/2007) assumes that all layers coordinates are in meters.
At this time it is suggested to place files in:
$HOME/starhydro_workspace/StarHydro and load them using "File->Open->StarHydro".
On Windows XP folder is usually:
c:\documents and settings\(your user name)\starhydro_workspace
On Mac OS X and Linux it is:
/home/(your user name)/starhydro_workspace
I'm working on File manager that will make this easier.
USGS seamless map can be converted to Star Hydro using Arc Workstation using following scripts:
Gridname is the name of the grid in the Arc Workstation's workspace
Projectionfile is the file describing input paramters and output units (ZUNITS METERS, UNITS METERS).
%% Project using projection file from below
project grid gridname projected projectionfile
gridascii projected projected.xyz
%% Pit filling using ESRI fill method
fill projected filled sink
gridascii filled filled.xyz
%% Calculate flow direction
flowdir = flowdirection( filled )
gridascii flowdir flowdir.xyz
%% Calculate flow accumulation
flowacc = flowaccumulation( flowdir )
gridascii flowacc flowacc.xyz
%% To find original grid projection parameters use:
Sample projection parameters (projectionfile.prj):
Units DD Spheroid GRS1980