/*  CREATE A HYDROLOGICALLY SOUND DEM

template script:  mmm185_hyd_sound_dem_v2.txt
template script last modified 11/05/01 by Bill

1) save this script with a new name:   yyy185_hyd_sound_dem_v2.txt.

This script modified and run xx/xx/xx by xxxxx.

This script describes how to use the ArcInfo FILL command to create a hydrologically sound DEM (aka "depressionless DEM").  You'll also use the FLOWDIRECTION command to create a flowdirection grid.  Both will be useful later for identifying glacier basins and ice divides.

NEEDED:
yyy_dem

CREATED:
yyy_dem_hs, the depressionless DEM
yyy_flowdir

2) change yyy to project prefix

	START ARC

3) Start Arc, and:
	w ../modern/yyy
	&watch yyy_yymmdd.txt
	&format 6
	lc
	lg

4) Start grid
	grid

	CREATE THE DEPRESSIONLESS DEM

5) At the grid prompt, type:
	fill yyy_dem yyy_dem_hs sink

This could take a while.  Give it some time.  You should see, e.g.:
	Filling ...
	Number of sink(s): 617
	Number of sink(s): 27
	Number of sink(s): 1
	Number of sink(s): -1

then it will stop and the grid command will reappear.

6) lg, then
	describe yyy_dem_hs

everything look ok?

	CREATE THE FLOWDIRECTION GRID

7) At the grid prompt, type:
	yyy_flowdir = flowdirection(yyy_dem_hs)

*** MAKE SURE NOT TO TYPE IN ... (yyy_dem)

	VIEW THE NEW GRIDS

8) In ArcMap, open the new grids and make sure they look ok.

Note that the yyy_flowdir grid should only have these values: 1, 2, 4, 8, 16, 32, 64, and 128.  If it has other values, something is not ok.

	QUITTING

9) quit out of grid, then arc.

Done.

/* -----------     NOTES   -------------
Write below any comments you have on unusual or unexpected steps, errors, etc.  Include any questions that you might have for Bill.



*/