Land trusts can benefit by applying GIS to the task of better understanding the region in which they operate. These landscape assessments can provide valuable context for defining mission and focusing strategic plans.

Landscape assessment usually has two parts - assembling and depicting data about your region, and generating statistics that you can use in goal setting and performance measurement.

REGIONAL LANDSCAPE MAPPING

Regional mapping depends somewhat on the size of your region (county, metropolitan region, state or more), but here are core maps that should inform most landscape assessments:

• Base  - jurisdictions, roads, cities/towns, protected lands, streams, rivers, lakes and other waters, urbanized "footprint", and topography (usually shown as shaded relief)
• Property - legal parcels, shown by common owner and by size classification
  
• Natural factors - soils, rivers/streams by classification, elevation levels
  
• Biodiversity - vegetation, habitat classifications, key corridors and linkages for animal migration, threatened and endangered species (federal and state)
  
• Working landscape - farmland (crops), ranchland, timber zones, aquaculture/fisheries and other natural resource-based economic uses
  
• Protected lands - lands protected primarily for their open space uses, subdefined by level of agency (federal to city and non-profit), degree of public access or other criteria, plus trails or other public access
  
• Planning - master/general plans designations, zoning classifications, urban service areas, etc.
  
• Threats - projections of urban and/or rural development, invasive species, pollution, soil erosion or other non-development threats
  

Other maps could include visibility analyses (areas that can be seen from major roads or other key viewpoints) and other more analytical looks at the landscape.

Using all these factors in an assessment can be quite daunting, but by assembling this data in one coordinated effort, a land trust is well-positioned to do strategic planning as well as support full conservation planning or other prioritization efforts.

DATA ABOUT YOUR REGION

GIS is particularly useful for generating quantitative data about a place. Within GIS exist tables of data about places called "attribute tables" - basically spreadsheets, where each row is a geographic feature (e.g., a property parcel) and each column is data about that feature (e.g., owner name, parcel size, date purchased, etc.).

There are generally two ways you can apply GIS to securing data about your geographic places:

Basic summaries - in GIS software if you select a group of features, you can run a very standard query that gives you totals, averages, maximum and minimum values and other quick information (e.g., select 10 land holdings, run summary function and get total size of group, plus other information).

Analytical queries - GIS excels at very robust queries of data, particularly where one layer is used to select out features of another layer (e.g., select all croplands and use that to "cookie cutter" out the parcels they exist in, then tell me how many acres are in that selected parcel set). For land trusts, such queries can result in information that is very complex and useful - e.g., finding all parcels where their distance from old growth timber stands is a certain number of feet.

Data tables (in the form of DBF or Excel spreadsheets) can be exported from most GIS software.  If you have a GIS layer of protected lands, for example, you can export the attribute table to a spreadsheet (or database) and then run totals, do various comparisons based on sorts or selections and use that data in reports and presentations.

For those looking to know more about such GIS analysis, ESRI publishes a number of excellent instructional guides - see their web site store.