Where will cities grow in the future? And how will this impact conservation efforts?

By Derek Van Berkel, John B. Vogler & Ross Meentemeyer

A growing concern for conservationists is the ongoing increase in global human population that is accelerating urbanization and rapidly transforming green landscapes to impervious built environments.  The emerging development challenge is: where (and how) can people live to conserve and sustain the natural resources needed for sufficient food, water, and energy production while maintaining special places for wildlife and outdoor recreation and minimizing the ecological footprint of cities?

Urbanization

As part of the Mega FUTURES project, the South Atlantic LCC is tackling this complex problem in close collaboration with The Center for Geospatial Analytics (CGA) at North Carolina State University. Over the last 3 years, researchers at the CGA have developed a geospatial computer model called  FUTURES (FUTure Urban-Regional Environment Simulation) for simulating urbanization and landscape fragmentation over large regions in an effort to help identify alternative futures that can lead to more sustainable and resilient cities and landscapes.

The FUTURES model is like SimCity™, the popular first-person computer game that simulates city expansion, but, unlike the game, FUTURES combines actual population data, site suitability factors, and the spatial structure of current settlement in a computer algorithm that projects where and how urban development is likely to grow over time. The model operates much like the relationship between developers and landowners. ‘Developers’ pick different locations that might be suitable for constructing housing developments. This process is driven, for example, by land use policies that influence how close to existing urban areas new developments may occur and by housing density regulations. Developers ask ‘landowners’ if they are willing to sell their land for the purpose of new development. Willingness to sell is influenced by factors such as landowners’ attachment to their land and the attitudes of their neighbors concerning development. Including the interaction between developers and landowner allows us to more closely simulate how urbanization actually happens in reality. Importantly, we are also able to explore how establishing new protected areas or denser settlements in certain locations will impact urban growth and landscape fragmentation in other locations. Simulating these spatial interactions across landscapes are critical for understanding unexpected tradeoffs and possible win-win scenarios of conservation efforts.

Researchers at the Center for Geosptial Analytics have applied FUTURES to the South Atlantic LCC region to simulate urban growth between 2010 and 2035. The region has been experiencing a population boom and this growth is expected to escalate in the coming decades. FUTURES projections show that most urban expansion will occur in the major urban centers with a majority of the hinterlands seeing a stagnation. Infill scenarios will limit the extent and magnitude of growth while sprawl scenarios will increase fragmentation of forests and farmlands surrounding existing urban centers. Explore the FUTURES sprawl scenario for yourself in the online interactive story map.

Land change projections are helpful for understanding and visualizing the patterns, processes, and consequences of urban growth. For example, natural resource managers can use these simulations to prioritize areas for conservation that would maintain vital wildlife habitat corridors or to identify locations that are less viable for conservation due to extreme urban development pressure. The FUTURES simulations are an important springboard for initiating dialogue about conservation priorities and helping us untangle complex problems involving ecosystem service tradeoffs and the perspectives of many different stakeholders.  

As part of the SmartSLEUTH project, we have made FUTURES open source and free for public use. Users can now download the a free open source software called GRASS, provide geospatial data and population forecasts for their own study systems, and run simulations and scenarios aided by  online help guides. Users with programming experience can also modify the FUTURES code, tailoring the software to help answer their own advanced urban growth questions.