/*  EDIT GLACIER FRAGMENTS

template script:  mmm205_edit_glcr_frags_v1.txt
template script last modified 11/7/01 by Bill

1) save this script with a new name:   yyy205_edit_glcr_frags_v1.txt.

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

The script that isolated glaciers from ice masses, along ice divides, left us with a few "errors" or artifacts that need to be edited.  We will deal now with the first of these:
	"glacier artifact fragments", where a small ice mass is split into two or more slivers 'cause there were just a few scattered "toe" pixels to define watersheds.

NEEDED:
t_gl_ed01
mmm205_edit_glcr_frags_1.jpg, a visual example of glacier fragments.
mmm205_edit_glcr_frags_2.jpg, the same area, showing the fragments after they have been edited into a single glacier.


CREATED:
modified t_gl_ed01

	START ARC MAP

2) Start ArcMap

3) Add t_gl_ed01, and change the symbology:
	categories
	unique values, many fields
	value fields:  minor1, t_gl_ed01#
	add all values
	uncheck "all other values"
	select and remove the "0,XXX" values
	ok

You should now see each glacier with a different color.

	EDIT THE FRAGMENTS

4) You might want to close the table of contents, and you might also want to add yyy_shaded, and make the glaciers partially transparent.
	Then zoom in and systematically navigate, until you find a "glacier artifact fragment".  This is something of a judgement call.  To get an idea, open the visual example: mmm205_edit_glcr_frags_v1.jpg.

This image depicts, near the center, four adjacent fragments, from dark blue on left to light green on right.  The divides between them aren't at a clear ridge top, but rather separate flow down glacier.  ELA's and other glacier parameters would be misleading, especially for the left two fragments. 

Small glaciers are probably ok, though, if they are on opposite sides of a significant ridge.  Also, we don't want to delete any polygons.  We only want to remove the arc separating adjacent fragments.

Nonetheless, I think we should err here on the side of correcting more fragments, rather than less.  The more we merge fragments into glaciers, the more broadly averaged the glacier parameters will be.

If you're unsure about what constitutes a fragment, let Bill know.
	
5) Once you found a fragment, start editing and:
	make sure the target layer is t_gl_ed01
	click on the shared edit tool
	click on the interior arc separating one fragment from another

fyi, it doesn't matter which order you do it, or which fragment's attribute values get carried over to the other fragments.

	after clicking on an interior arc, you'll see it turn orange
	hit the delete key

6) Continue with other fragments, moving systematically across the map, and:
	periodically save edits
	write notes at the bottom of this script for anything unusual
	
7) When done, stop editing, and:
	save edits
	quit arc map

Done.

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



*/