Migrating GRIDS and Shapefiles to FGDB Using Python

Sunset 3
The Drawdown tool within RegGSS can be used to create a hydrologic drawdown models (grids) in a non-leaky aquifer for single or multiple well systems. The tool is also a library of over 2,500 grids that allows for storage and retrieval of the created drawdown grids and contours.


Drawdown creates a directory named the same as the permit application number, for example 080410-22. The individual grids are stored within this directory and are named “application number – version”, for example 080410-22-1. Each grid can also have contours and those are named “contour – version”, so the contours for 080410-22-1 is just contours-1.

We did extensive testing on our test environment and thought we had figured it all out. But how often does your test environment faithfully duplicate production? Especially, in a Windows XP to Windows 7, ArcGIS v9.3 to 10.1 migration?

Here are the problems as we migrate to ArcGIS v10.1:

  • ArcGIS v10.1 wants everything in a geodatabase (will use a file geodatabase)
  • Geodatabases do not like grids that begin with numbers (will prefix grids with a “g”)
  • Geodatabses do not like grids or contours that have dashes “-” in the name (will use underscore “_”)
  • Prior to ArcGIS v9.2 grids were stored with auxiliary files, for example 080410-22-1.aux which stored statistical information about the grid. At ArcGIS v9.2 in addition to aux files ESRI added aux.xml files, for example 080410-22-1.aux.xml. ArcGIS v10.1 does not recognize the older format with the aux file alone. (we will generate aux.xml files).

The image below is a look at the output of Drawdown for a single well system.
Drawdown Grid

You can take a look at the python code on GitHub.

Juan Tobar, Supervisor – Geographers, Regulation GIS, SFWMD


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