Development Threat Analysis shows where unprotected open space lands are most likely to be developed over a specific time frame. Considering this analysis in conjunction with data on lands with high ecological or cultural value can help governments and conservation organizations in determining conservation priorities.

Summary

Development threat analysis graphically depicts where unprotected open space lands are most vulnerable to development pressures over a specific time frame, usually 10 to 20 years. To help identify areas where conservation efforts should be prioritized, the mapped results of the development threat analysis are overlaid with maps showing areas with high ecological, agricultural, recreational or other conservation values.

Analysis of development pressure is primarily based on population and employment forecasts and additional assumptions on attractors to development, such as transportation access and public sewer and water service. Some analyses incorporate parcels’ access to employment centers and municipalities’ vulnerability due to weak resource protection ordinances. More sophisticated techniques can include land value projections.

In addition to helping determine conservation priorities, development threat analysis can provide the information needed by government to adjust public policy to redirect development to more suitable areas.

Development threat analyses are not intended to and cannot replace local knowledge about specific real estate values or parcels in which developers are interested.

Track Record

Development threat analyses have been completed in the mid-Atlantic region in areas including the 5-county southeastern Pennsylvania area (2003), the New York - New Jersey Highlands (2002), the Schuylkill Watershed (2007), the Chesapeake Bay Watershed (2007), the state of Maryland (2006) and the Commonwealth of Virginia (2006).

Typical End Users

This analytical method is designed to be used by state, regional and local governments, as well as nonprofit conservation organizations in prioritizing their land conservation work.

Conservation Impact

Once the development threat analysis has been completed, simple to use maps show where development pressures will most likely threaten lands of ecological or other significance, suggesting where conservation actions may be most urgent. Governments and conservation organizations can use this information to prioritize their conservation efforts and act strategically with limited resources.

What You'll Need

A consultant or staff person with the appropriate modeling skills and knowledge.
Access to data.
The use of Geographic Information System (GIS) mapping is advised, as it makes it much easier for multiple sources of data to be combined and manipulated.
In areas where a recent development threat analysis has already been developed, the user can simply review the resultant maps and use the information to prioritize their conservation agendas.

Obstacles and Challenges

Conducting a development threat analysis can be costly and time consuming. It can cost between $5,000 and $50,000 due to the research required to select and adapt a suitable technique, differing availability and quality of data, and the processing and presentation of results.
Creation of a model for conducting a development threat analysis and generating results likely depends on the willingness of an agency or consultant with appropriate modeling skills, knowledge and access to data being interested in assisting with development of the assessment.
If key stakeholders are not engaged in the analysis process, it is less likely that the results of the analysis ultimately will be translated into conservation action.

Contents of Main Description

INTRODUCTION
NO SINGLE STANDARD
GIS IS RECOMMENDED
SCALE AND ACCURACY OF THE ANALYSIS
EXAMPLES OF RECENT MID-ATLANTIC DEVELOPMENT THREAT ANALYSES
   Chesapeake Bay Program, Resource Land Assessment
   Development Threat Assessment for SmartConservation
   Development Threat Assessment for the Schuylkill Priority Lands Strategy

INTRODUCTION

Development threat analyses typically involve the collection and processing of a variety of socio-economic background data. Data selection, collection and processing techniques can be complex and challenging. Extensive research is frequently required by the modeler to investigate prior successful modeling techniques and approaches. Knowledge of the age, scale, format and precision of available data is then used in conjunction with the modeling technique options to make final decisions about what data can be used and how to best compile and process it to achieve meaningful analysis. Some of the modeling techniques used in development threat analyses in the Mid-Atlantic region are briefly characterized at the end of this description.

The end result of the development threat analysis process is frequently a Geographic Information System product that enable users to overlay a base map of the project area with maps depicting areas where development pressure is projected to be the greatest and maps showing the area’s natural resource priority areas. The natural and manmade resources found in the area can be shown on separate overlays that can be easily added to, and taken off of the base map so the affect to different resources can be clearly seen. Examples of data that can be shown on map overlays are the location of various habitat types, current and future land use, proposed infrastructure, land cover, floodplains, drinking water supplies, current and projected population densities and cultural resources such as historic landmarks and archaeological sites.

The results of development threat analyses have a wide variety of applications. They allow end users to prioritize conservation work by focusing land purchase and other preservation efforts to areas that are both ecologically valuable and highly vulnerable to development. Threat analyses can allow both conservation groups and governments to be proactive, instead of reactive to development pressures. By showing how development is likely to affect natural, agricultural and other resources, analyses can guide county and municipal governments on the development of their comprehensive plans and land development ordinances as well as their investments in public infrastructure.

Large-scale threat analysis, or the combination of analyses from neighboring areas, allow regional and interstate conservation efforts to be more strategically planned. Additionally, a development threat analyses can provide important planning tools in creating and maintaining sustainable resource-based industries, such as timber and wood product industries.

NO SINGLE STANDARD

No single “standard” development threat analysis technique has been accepted or adopted for completing development threat analyses. A variety of approaches have been developed in recent years, each customized to match the data available for the region being studied.

GIS IS RECOMMENDED

The use of Geographic Information System (GIS) mapping is advised, as it will allow data from multiple sources to be combined and manipulated. GIS allows for complex analyses to be done on the interaction of multiple factors affecting an ecosystem, and a GIS can be used to create maps where multiple data sets can easily be overlaid. Depending on the software used, people other than those conducting the analysis may be able to download free, simple to use software that will allow them to view the results of the analysis.

SCALE AND ACCURACY OF THE ANALYSIS

The scale and age of the data inputs to the process are critical to the accuracy and detail of the analysis. Regional-scale datasets will almost always be less accurate then local data, because regional data inputs have to be consistent across large areas. This invariably leads to the need to use the lowest common denominator for data available -- in terms of scale, age and precision. The larger the project area, the less precise the data inputs and resultant outputs are. Local data and analysis will frequently be more reliable than landscape and regional scale analyses because on-the-ground local knowledge is more accurate. However, local analysis is frequently infeasible due to lack of available data in a usable GIS format, and due to the relatively high costs of developing models for smaller areas. Economies of scale force most development threat analysis to be completed at the landscape or regional scale.

EXAMPLES OF RECENT MID-ATLANTIC DEVELOPMENT THREAT ANALYSES

A short synopsis is provided to give the reader an overview of each project; for detailed information, please follow the links provided:

Chesapeake Bay Program, Resource Land Assessment

The Chesapeake Bay Program, Resource Land Assessment developed six analytical approaches for assessing the value of forests, farms and wetlands within the Chesapeake watershed using GIS models to manipulate and combine data from a variety of sources. The resulting assessment models can be utilized individually or in combination. The composite data sets can be reclassified and applied at different geographic scales based on the needs of the user.

One of the analyses is the vulnerability model. The vulnerability layer evaluates the relative potential risk of future land conversion to urban uses. Vulnerability is defined as a function of suitability for development and proximity to growth “hot spots.” The vulnerability layer is useful as a stand-alone layer to evaluate development trends, but can also be combined with the other resource land assessment layers to prioritize land conservation efforts.

For more information, visit http://www.chesapeakebay.net/rla.htm

Development Threat Assessment for SmartConservation

The Development Threat Assessment for SmartConservation, which analyzed the 5-county area surrounding Philadelphia, was compiled by the Delaware Valley Regional Planning Commission for the Natural Lands Trust between 2002 and 2003. The data used was already partially or completely available, allowing the completion of an analysis that would have otherwise been too costly and time-consuming. Five subcomponents of data were used:

Trend friction map
Employment center travel time analysis
Building activity
Vulnerability index
Sewer Service Areas

Development Threat Assessment for the Schuylkill Priority Lands Strategy

The Development Threat Assessment for the Schuylkill Priority Lands Strategy was also conducted by the Delaware Valley Regional Planning Commission (DVRPC) for the Schuylkill Watershed in 2006-7. The assessment was based on a model acquired from California (UPLAN Model) and was calibrated for use in the DVRPC region. On a county level, the model spatially assigns population and employment forecasts to acres consumed based on attractors (transportation access, public sewer and water, proximity to existing development), discouragements (congestion) and masks (developed land, protected land, wetlands).

For more information, visit http://www.schuylkillprioritylands.org

Conservation Tools

Development Threat Analysis

Experts

Featured Library Items

Acknowledgements

Disclaimer

Copyright