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The Rate that Resources are Protected

It is possible, using the assumptions laid out in the background section, to evaluate the rate in which different resources will be protected.

The order in which parcels are ranked for acquisition can be linked to information about the resources present in each parcel. This is accomplished by overlaying the data layers for each resource with the parcel database. Linking these data with the ranking system allows the amount and type of resources that will be protected with each acquisition to be quantified.

The graph on the right shows the percentage of the area protected for each resource group as a function of the amount of money spent on openspace acquisition using assessed value. This is measure by estimating the amount of unconstrained land that is of each resource type in each area.

For example, if the parcels are bought in the order they are ranked, and 5 million dollars is spent on openspace protection, 40% of groundwater resources will be protected, and 55% of cultural resources will be protected.

The slope of the lines in the graph show that more resources are protected in the first 10 million dollars that is spent, then in the second 10 million. This illustrates that the ranking system causes the openspace plan to buy the most cost-effective resources first. This is the intention of the scoring system, and it seems to be working correctly.

Another important attribute of the graph is the distance between the lines. At any given point in the execution of the openspace plan, the difference in area protected of each resource is small.

The scoring systems both give some resources more weight then others. This is not realized in this model of potential outcomes and may be a failure of the openspace prioritization scheme presented in this study.

Percentage of the Area of Each Resource Group Protected - Web Survey Scoring System

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Percentage of the Area of Each Resource Group Protected - Commissions' Scoring System

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For example, in the web survey scoring system, the number of points given to farmland areas is one sixth the number of points given to protection of water resources. This is not reflected in the amount of area that is protected in the respective resource groups. More of the agricultural area is better protected then groundwater area almost throughout the entire process.

The inability for the weighting to impact the process is due to the scoring systems preference for co-occurring resources. The scoring systems most important property is that they find areas that have co-occurring resources, everything else is secondary. Further discussion of this is in the analysis of the difference between scoring systems page.

Most of the land in Charlestown has more than one resource. A visual inspection of the maps in the metadata section will illustrate this point. When a parcel of land is protected, multiple resources are protected at the same time. Despite agriculture's low weight in the scoring system, having other resources that co-occur with the agriculture parcels causes these parcels to receive a high score.

Finally, it is evident that there are very few differences between the two graphs, despite differences in the scoring. There is a in-depth analysis of the difference between the two runs on this site.

6.01 Matthew Amengual