Jump to content
GMS, SMS, and WMS User Forum

Lost data when merging observed flow coverages.


PGraafstra
 Share

Recommended Posts

Hi,

When I try to merge multiple coverages that have specified observed flow to a specific arc group, the merged coverage does not contain all arc groups from the original coverages, but only some of them (not the same arcs every time).

Any suggestions how to deal with this, or a different approach to assigned multiple instances of observed flow to complex arc groups?

I know there are ways to manually group the arcs in a single coverage and take it from there, but I have an intricate system of streams that is classified according to stream width. The 'observed flow' is used as a workaround by setting its weight to 0, as I need the jacobian matrix calculated by PEST for further analysis; manually grouping all these arcs is not really a workable option.

Any advice is appreciated, thanks in advance.

Pytrik

Link to comment
Share on other sites

Hi,

Since posting this, I did a little more digging and managed to solve the problem myself.

It seems to be related to the structure of the shapefiles used to create the individual coverages before merging:

- Shapefiles created by ArcGIS work without a hitch.

- Shapefiles created by R (I used the maptools package), somehow seem to cause these problems.

I don't know how GMS deals with these files, but I am guessing the problem has something to do with the lack of *.shp.xml and *.sbn files when creating files through R. Oddly enough, reading the shapefiles and mapping them to a single coverage has not given me any trouble, it is the merging process that somehow causes a problem.

Pytrik

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
×
  • Create New...