GIS Data Management Tips for Land Trusts

While Landscape does a great job of presenting and creating map data alongside the data you’re working with, most organizations also choose to use GIS software like ArcMap, ArcGIS Online, or QGIS to manage their GIS data, create complex maps, and perform queries on their geodata. Here are a couple of tips for organizations who need to find a way to manage and organize their geodata.

  • Use a single master shapefile for each different category of map data. Do not use a single shapefile for each feature.

For example, maintain one master polygon shapefile of ALL of your boundaries, one point shapefile of all known issue points, one line shapefile of all monitoring tracks walked, etc. Keeping separate shapefiles of each individual boundary gets messy quickly, and it means people have to spend a longer time searching for the ‘right’ one. They will also inevitably have unreliable attributes. It can be alright to maintain a folder for very property-specific data (here are the different proposed building envelopes or the location of all the apple trees) but everything else should be maintained as a group. At the very least, maintain a single master boundary shapefile for all of your holdings.

‘But if the map has a shapefile of all boundaries how do I show just one boundary in a map and not all of the other ones?’

You’ll be tempted to export a single shapefile of just what you want and use that in the map you’re creating, but try not to, as it just creates more mess. Instead, use the definition query feature (in ArcMap or ArcGIS Pro) or the query builder (in QGIS) to display just the features you want. While it looks complex at first glance, a definition query is just a way of saying ‘show me just the features that have the name X’ or ‘show me all of the features that have an area of X or Y’. Learning to use this feature takes about five to ten minutes, and will drastically simplify your map making workflow.

  • Limit the number of attributes in each master shapefile

Limit the data in the attributes to just data that pertains to the shapefile itself and the very basics needed for identification. Rely on your record keeping system (like Landscape!) for everything else. For example, if your boundary shapefile has ‘owner name’ as an attribute, it’s serving as just another place where that name needs to be kept up and could potentially be incorrect. ‘Boundary Name’; ‘ID Number’; ‘Length’/’Area’; and maybe ‘Interest’ are all that need to be stored in the attributes of your master boundary shapefile. Also: Adopting an ID number system (discussed in this previous post) for your holdings will make it much easier to perform joins (join the attribute table of the shapefile with another table if need be).

‘What about using geodatabases instead of shapefiles?’

This is a good question to explore if you have a dedicated GIS specialist on staff who can assist other staff members. Otherwise it’s probably not worth the added complication.