Frequently Asked Questions and “Lessons Learned” – Geodatabase Templates

 

Keep a backup copy of the templates

In the event things go wrong, you’ll have a backup copy instead of having to redownload the templates.

 

1) Spatial Index (After loading my maps into the geodatabase I can’t see them when I zoom in.)

The geodatabase templates have a predefined standard geographic coordinate system: “GCS_North_American_1983.” If your input land use maps have a different coordinate system/map projection then you must recalculate the spatial index after loading your maps. (If you do not then you will experience display problems.) Here’s how to fix it.

1.      Load all counties into the existing land use geodatabase template, using the feature class provided.

2.     In ArcCatalog, right-click on the feature class in the template, go to Properties, go to the Indexes tab and Recalculate the Spatial Index.

 

2) County Boundary Discrepancies (My land use maps do not fit together.)

If your land use data was not built using Census County boundaries, they are probably different than what has been required by the Rules for Local Planning. They may not even fit with each other when assembled. You’ll need to do the following:

1.      Obtain census county boundaries of all of your RC’s counties.  They are available for download at www.georgiaplanning.com/dataforplanning.htm

2.     Delete the counties that are outside of your RC.

3.      In ArcToolbox, “Union” the land use feature class and the county boundaries for your region.

4.     After the Union, polygons with a -1 in the “FID_County” field are outside of the county census boundaries and can be deleted.  Remaining polygons that do not have anything in the ELU_Code field are areas inside the county census boundaries that need to be populated with valid land use codes.

See also 5 below.

3) Domain Default Display Setting (My land use values disappeared after I loaded my maps.)

After loading your maps into the geodatabase you may experience an apparent problem seeing the land use codes when viewing the attributes; instead you may see the land use code descriptions. This is caused by a default display setting in both ArcMap and ArcCatalog. To change this,

  1. In ArcMap or ArcCatalog, go to the ‘Tools | Options’ menu.
  2. On the ‘Options’ menu, go to the ‘Tables’ tab and click off the setting that says, “Display coded value domain and subtype descriptions.” Your view of the tables will now display the domain codes instead of their descriptions.

 

4) Topology (How do I setup ArcMap to check for topology and validation issues?)

In an empty ArcMap project, add the topology from the land use template first. It will ask if you want to bring in the associated feature class. Click Yes.  This ensures your feature class and topology in ArcMap are associated with each other.

1.      First, Validate Topology for the entire feature class.

2.     Then, Validate attributes for the entire feature class.

 

5) Topology Problem (The new land use feature class has gaps after I have loaded my land use maps.)

If your land use data was not built according to the Rules for Local Planning, it might have gaps or holes in it where no polygons or land use codes exist. This is typically the result of a map assembled using parcel data that did not have polygons constructed for the roads or other transportation and utility corridors. This is unacceptable as it would leave out all or portions of an entire class of land use, i.e., ‘Transportation/Communication/Utilities.” This is why one of the two topology rules set for the geodatabase is “Must Not Have Gaps”.

The quickest way to correct this is to do the following:

  1. Use Tip 2 above to simultaneously clean-up boundary problems (especially on your region boundaries) and to create polygons where you previously had gaps or holes between your individual land use maps, and where corridors were not included in the map.
  2. Use ArcMap to add land use code values to the new polygons. If they indeed all belong to the ‘Transportation/Communication/Utilities’ class you can now code them all with a single calculation.
  3. Polygons with a -1 in the “FID_County” field are outside of the county census boundaries and can be deleted.

Alternatively, you can use the ArcMap ‘Fix Topology Error’ tool and its predefined fix option to ‘Create Feature’. See this demonstrated in the ‘Topology and Validation’ presentation at http://www.georgiaplanning.com/zipdata/landuse/Step2.exe

See also 2 above and ‘Topology Error Fixes’ in ArcGIS Desktop Help.

6) Topology Problem (The new land use feature class has overlapping features after I have loaded my land use maps.)

If your land use data was not built according to the Rules for Local Planning, it might have overlapping polygons, especially along county or city boundaries. This is typically the result of a maps assembled using different boundary base map sources or versions. This is unacceptable since city and/or county jurisdictions do not overlap. This is why one of the two topology rules set for the geodatabase is “Must Not Overlap”. The quickest way to correct this is to do the following:

1.      In ArcMap, use the ‘Fix Topology Error’ tool and its predefined fix option to ‘Merge’, which adds the portion of overlap from one feature and subtracts it from the others that are violating the rule. You will need to pick the feature that receives the portion of overlap using the Merge dialog box. This fix must be applied to each ‘Must Not Overlap’ error individually.

2.     Recheck topology.

See ‘Topology Error Fixes’ in ArcGIS Desktop Help.

7) Map Loading Problem (My land use codes will not match those in the geodatabase domain; my maps have values like 1100, 2100, 9100, etc.)

Land use code values like these indicate that the Rules-optional APA Land-Based Classification Standard (LBCS) was used. Several counties (Elbert, Greene, Jasper, Lamar, Randolph and Stewart) were mapped using LBCS for plans that were submitted during fiscal years 2004, 2005, and 2006. You have two options:

  1. You may continue to use LBCS by using a special geodatabase template; please contact DCA for details.
  2. You may convert LBCS codes to standard Georgia land use codes, using the conversion table at http://www.georgiaplanning.com/zipdata/landuse/LBCStoLUCODE.zip

 

8) Map Loading Problem (My land use categories have variants like “Rural Residential”, “Residential, High Density”, and “Residential, Low Density.”)

Land use code values like these indicate that subcategories were assigned to the basic classes. To correct this generalize them all to “Residential” before loading your map into the geodatabase template.

 

9) Vintage of Input Land Use Maps (Can we use maps of a city or county that has been updated since their last land use plan was submitted to DCA?)

Yes, you can input land use maps that have been compiled or updated since the last approved comprehensive plan or update. You cannot use maps that are older than those presented in the last comprehensive plan or update. Remember that the regional compilation is not a synoptic view or single snapshot in time; it is rather a mosaic of several snapshots. As long as you calculate the ‘PLAN_DATE’ field for each local government separately with its actual date we should be able to track the currency of local governments in the regional map.

 

10) Map Loading Sequence (If we upload each individual county, and validate topology and attributes, when does the upload of all counties become a single regional map?)

The procedure to build the regional map can follow one of two scenarios.

 

Scenario 1- You can load and validate each local government individually into separate copies of the template feature class. This takes care of all the coding issues with each map separately. Usually the coding errors are unique to a map, therefore, you can correct problems in bulk without having to reselect records from a larger combined set of maps. The final step would be to load all these individually corrected maps into the regional map.

 

Scenario 2- You can load all your maps initially into the same template feature class; then run validation of codes and topology.

 

11) As described in the contract, the RC needs to create a local compiled Future Development Map.  Section B (2) states that the RC shall compile the Local Maps into Regional Maps.   However, in  Section B (5)1;  the contract states “The Commission shall provide a Future Development map, mapping all areas within the boundaries of the region as polygons, assigning character areas as prescribed in the relevant Rules:”  Since several of the counties within our region have not completed a plan under the 2005 standards that prescribe a Local Future Development Map and will not until 2014,  are we supposed to create character areas for those jurisdictions?  Or should the requirements described in Section B (5)1 be used for the Regional Development Map as required under the Regional Planning Rules. 

 

For local governments with maps prepared under the older rules, their Future Land Use maps should instead be compiled into the Future Development regional map. During future plan revisions these areas can then be replaced with the character areas of the Future Development map. The template geodatabase available at http://www.georgiaplanning.com/workprogram.htm already has the codes built in to accommodate both the "typical character areas" from the state planning recommendations (http://www.dca.ga.gov/development/PlanningQualityGrowth/programs/SPRs/SPR.CharAreas.pdf) as well as those from the land use categories as defined in the Rules (http://www.dca.ga.gov/development/PlanningQualityGrowth/programs/downloads/MinimumStandardsAdopted.pdf).

 

12) I am working on our Future Development Map layers, trying to bring them into your FDM template.  Because there’s no FDM “code” included in the attribute fields, I am trying to match my Character Areas with the ones listed in your template.  Since most of the character area names were developed with the assistance of the communities, mine do not appear to be standardized into the 28 categories listed in DCA’s template; but my question is, should they be?  Should my first step be to rename the character areas to match those included in the geodatabase template?  Otherwise, they will not be loaded into the template correctly, right?

The naming of character areas is open-ended so if you have different character names you should first add them to the domain in the template; then your maps should load OK.

13) When using ArcCatalog I try to Load data into the FDM geodatabase and the ‘Load Data’ option is grayed out.

The most likely cause of this is that the geodatabase template has been compressed. In ArcCatalog, use the mouse to right-click on the geodatabase and then select the ‘Uncompress File Geodatabase…’ option.

If you encounter other problems or discover other tips that would be helpful to your colleagues let us know and we’ll post them here.

Send questions or tips to GIS @ dca.ga.gov

 

Last updated 12/11/2009