Prioritizing land preservation: a GIS approach

For organizations that protect land by purchasing property (or the underlying development rights), a simple but harsh reality reins: Land is expensive. Money is limited. So you have to spend wisely.

In this regard, a new study may help land conservationists identify the highest priority properties for preservation. Researchers Yuri Gorokhovich and Andrei Voustianiouk have tested a GIS tool that incorporates spatial data to rank individual properties based on user-defined criteria. They applied the tool to coastal parcels on the Long Island Sound in New York. 

The method involves measuring property attributes including size (the bigger the better) and distance to certain desirable features such as coastlines and tidal wetlands (the smaller the better). The attribute values are then normalized on a scale of 0 to 1, weighed based on the subjective importance of the attribute, and added together to create a final score for the property. So if a manager placed greater importance on distance to coastline, that normalized attribute value would be given a greater weight in the scoring.

One complication with this approach is figuring out what criteria to use in the prioritization - this is obviously going to depend in part on the goals of the organization. If you were focusing on protecting wetlands, you would obviously give greater weight to a metric involving wetlands.

This is where the planning tool can be particularly helpful. The researchers ran a number of different weighting schemes and conducted further analysis to see which parcels consistently scored the highest in all the scenarios. 

This tool (or methods like it) could be very helpful for organizations that do not currently use a systematic approach for prioritizing land conservation efforts. My guess is that many organizations rely mostly on a combination of intuition and going for the best opportunities that present themselves (i.e where landowners have expressed interest, where political support exists, etc.).

While there is nothing inherently wrong with those approaches, adding a systematic tool into the planning arsenal might be a good idea. It could allow organizations to improve their decision-making, and better communicate to prospective funders. It could also help organizations figure out which doors to knock on instead of waiting for landowners to come to them.

In a world where land prices have fallen to historic lows but so have funding levels, conservation groups need all the help they can get.  

--Reviewed by Rob Goldstein

Gorokhovich, Y., & Voustianiouk, A. (2009). Prioritization of coastal properties for conservation in New York State Journal of Coastal Conservation DOI: 10.1007/s11852-009-0081-8