Combined Data

The agricultural, ecological, and recreational data layers were brought together into two unique combined displays. In the first combined display, each of the three subcomponents were overlaid onto the same map (see Map 7: Open Space High Priorities Overlaid). In this overlay map, the ecological resources and agricultural layers retained their original values, while the original 10 quantiles of the recreation layer were grouped into five quantiles and assigned values from 6 through 10. In the overlay map, only cells receiving a value of 8 or higher are shown. Cells for each subcomponent are indicated on the map with a different color. The 3 subcomponents were overlaid after developed and protected lands were removed from the analysis.

In the overlay map, the combined area of high-resource-value cells (8, 9, 10) is 466,300 acres. A breakdown follows:

• High value for agriculture only: 160,400 acres
• High value for ecological resources only: 150,100 acres
• High value for recreation only: 39,900 acres
• High value for agriculture and ecological resources: 58,500 acres
• High value for agriculture and recreation: 11,400 acres
• High value for ecological resources and recreation: 39,200 acres
• High value for all three subcomponents: 6,800 acres

Second Display

In the second display, the values for each subcomponent were combined and reclassified (see Map 8: Open Space High Priorities Combined). In this version, the ecological resources and agricultural layers retained their original scores. The recreational subcomponent was once again reclassed into five quantiles and assigned values from 6 through 10. Combining the three components into one map is useful because it shows one overall set of open space priorities in the region. The intention is not to judge agricultural lands vs. ecological resource lands vs. recreational lands, but to show where priorities intersect and reinforce one another.

Using this system, cells received a combined low score of one point to a high of 30 points¹¹. Developed and protected lands were then masked out of the analysis, and the remaining cells were reclassed into ten quantiles. This prioritization shows all lands within the region that are currently undeveloped and unprotected. The resulting composite map shows all 10 quantiles. Because the data was reclassed after removing developed and protected land, approximately ten percent of all undeveloped and unprotected lands (617,000 acres) fall into each quantile.

Combining the scores of all three subcomponents raises some concerns. For example, can land serve multiple open space uses at the same time? With regard to ecological resources and passive recreation, the answer, as discussed above, is yes. In fact, passive recreation is almost always sited on and contained within ecological resource areas. Therefore, it is reasonable to conclude that land that is valuable for both ecological resource conservation and passive recreation should be a higher overall priority than land that is only valuable for one purpose alone¹².

Somewhat less recognized is that recreational activities can also be compatible with agricultural lands. In several parks in the region, including Tyler State and Peace Valley parks in Bucks County, agricultural and recreational activities harmoniously coexist. Many trails within each park skirt the edges, or even run through agricultural fields. Of course, privately owned farms (whether or not preserved) are not open to the public, but in principle, agricultural and passive recreation activities can coexist. It should also be noted that agricultural and recreational lands overlap much less frequently in the analysis than ecological and recreational lands or ecological and agricultural lands.

Ecological and agricultural lands can also be complementary. Ecological lands proximate to agricultural lands help to control erosion and manage the hydrologic cycle. Conversely, agricultural lands proximate to ecological lands, highlight the natural beauty of the landscape and provide valuable habitat for some birds and grassland species. While high-value ecological resource and agricultural lands don't typically inhabit the same space at the same time, land can potentially be valuable for both purposes, i.e., preservation could be pursued for either agricultural or ecological reasons. Combining the agricultural and ecological resource components of the model into one prioritization bears this convergence out.

Rural Conservation Lands vs. Urban/Suburban Lands

For planning and strategic purposes, it is sometimes useful to simplify a region's landscapes. For its long-range plan, DVRPC divided the southeastern Pennsylvania region into two distinct areas: Rural Conservation Lands and Urban/Suburban Lands, shown on Map 9: Rural Conservation Lands. All of the region falls into one of these two categories. While Rural Conservation Lands do contain some pockets of development, and Urban/Suburban Lands contain small agricultural areas, parks, and other undeveloped spaces, each area has a distinct character and different open space preservation needs and opportunities. Therefore, it is useful to think about each of these landscapes separately.

Rural Conservation Lands are large areas that are primarily undeveloped. They contain large agricultural regions, natural areas, headwaters and stream corridors. Set within these lands are smaller towns and limited pockets of development. Rural Conservation Lands total 807,000 acres, or 57% of the region. As of 2000, 175,000 acres (22% of the total acreage of these lands) had already been developed, leaving 632,000 acres undeveloped. Of the undeveloped lands, 126,000 are protected, leaving 506,000 acres undeveloped and unprotected. Of these 506,000 acres, 401,000 acres or 79% are a high priority for agriculture, ecology and/or recreation.

By definition, Rural Conservation Lands contain the bulk of the region's remaining undeveloped and unprotected lands, as well as, not surprisingly, the great majority of high-priority resource lands. It is in these areas that the region's open space preservation activities will need to be concentrated. Protection of large, unfragmented open space landscapes in SEPA will depend on the effectiveness and success of these efforts.

While not nearly as significant in size, open space opportunities and high-priority lands within Urban/Suburban Lands are every bit as important for maintaining the quality of life of the region's developed communities. Total Urban/Suburban Land area is 602,000 acres, of which, 451,000, or 75%, are developed. This leaves 151,000 undeveloped acres, of which 40,000 are protected. Of the remaining 111,000 acres of undeveloped and unprotected land, 68,000 acres or 61% are a high priority for agriculture, ecology, and/or recreation.

¹¹ A one point total is the result for a cell that received a value of 1 for ecological resources and was not ranked for either recreation or agriculture. Philadelphia was not ranked for agriculture and only lands within the Greenspace Network were ranked for recreation.
¹² It should be noted that in some instances, passive recreation is not compatible with the preservation of ecological values. In these cases, passive recreation needs to be directed away from sensitive areas.