Urbanization and Estuaries – challenge and opportunity

These two very interesting papers came across the wires the other day and, while at face they may not seem all that related, we thought that – taken together – they suggest some exciting synergies for coastal urban environments.

A Meta-Analysis of Global Urban Land Expansion
by Karen C. Seto, Michail Fragkias, Burak Guneralp, Michael K. Reilly
Jobs & Dollars: Big returns from coastal habitat restoration
by Restore America’s Estuaries

The big picture on urbanization:

  • between 1970 and 2000, urban land cover expanded globally 58,000 km2, with the largest change in total urban extent occurring in North America
  • between 1970 and 2000, the average city in the study added 46,000 urban dwellers per year and 13.5 km2 of urban land per year
  • urbanization “results in changes in land cover, hydrological systems, biogeochemistry, climate, and biodiversity” but also “presents opportunities for efficient resource use and mitigating climate change”
  • the universal trend across decades and regions is a decrease in urban land use efficiency (urban land expansion rates exceed urban population growth rates)
  • projections suggest global urban land cover will expand 1,527,000 km2 (an area roughly the size of Mongolia) by 2030

The big picture on coastal habitat restoration:

  • estuaries are highly productive ecosystems  that are vital to our nation’s economy (coastal regions supply key habitat for 75% of U.S. commercial fish catch and 85% of U.S. recreational fish catch, generate 40% of U.S. employment and 50% of U.S. Gross Domestic Product, provide $214 billion annually in leisure and hospitality jobs)
  • human use and development have severely stressed estuaries over the last century
  • coastal habitat restoration provides clean water, bolsters fish and wildlife populations, protects coastal communities from storm damage, and creates recreational opportunities, all of which contribute to higher property values and more tourism
  • coastal habitat restoration (restoring natural water flows, rebuilding oyster reefs, removing obstacles to fish passage, replanting salt marshes and seagrasses) creates jobs – up to 32 jobs per $1 million invested, plus many more indirect and induced jobs – that cannot be exported

The link:  Urban areas in coastal zones are growing faster than upland urban areas.

  • According to Seto et al. (2011), “about 34% (99 out of 292) of the locations in the meta-analysis fall within 10m of low elevation coastal zones (LECZ).  For these urban areas, the average rate of urban land expansion from 1970 to 2000 is greater than 5.7%, and statistically higher than urban areas elsewhere”
  • According to Seto et al. (2011), “an urban area located in the coastal zone drives the rate of urban land expansion up by 0.829 percentage points compared to non-coastal zones”
  • NOAA projects 75% of Americans will live within 50 miles of the coast by 2025

The projected increasing pressure on urban estuaries presents both a challenge and an opportunity.  If we can restore coastal habitats to rectify our past mistakes and effectively manage future growth, we could transform our cities – integrating them with their environment – and generate jobs and good returns on investment in the process.

Please check out both studies for more detail – the urbanization paper provides much more detail on methodology and trends gleaned from the results, and the restoration paper includes some fascinating case studies.

This entry was posted in climate change, environment, eutrophication, flooding, habitat, planning, shellfish, sustainable development, wetlands and tagged , , , , , , , , , , , , . Bookmark the permalink.

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