Skip directly to: Navigation for this section | Main page content

John Muir Institute of the Environment

New Paper Explores the Environmental Impacts of Population Growth Scenarios in the San Joaquin Valley

The San Joaquin Valley is growing faster than Mexico and has poverty rates higher than Appalachia. Envisioning a future for the San Joaquin Valley in 2050 is a formidable task for regional planners, but a new publication from the Information Center of the Environment (ICE) at UC Davis will provide planners with better information about the environmental impacts of projected human population growth patterns. The patterns were constructed by ICE researchers using UPlan, a powerful geographic information system-based urban growth model developed at UC Davis. The model grinds through years of data to construct scenarios for future growth. The scenarios were included in the appendix of a Strategic Action Proposal released in October 2006 by the California Partnership for the San Joaquin Valley. The Partnership, created by the governor and headed by the Secretary of the Business, Transportation and Housing Agency developed the scenarios in a work group called Land Use, Housing and Agriculture (LUHA). Each scenario depicts future growth given a different set of planning policies such as: “Compact Growth,” “Farmland Protection” and “New Cities.”

Scenarios have become an essential part of communicating how today’s choices determine future growth. The Great Valley Center in Modesto has been presenting growth scenarios in conferences on valley issues and regional planning for several years. However many scenarios, including those proposed by the Partnership, emphasize economic and quality of life issues in the valley without the details of the impact of population growth on the region’s natural resources.

After several years of support from Caltrans to provide tools, data and modeling support for Valley planning, ICE researcher Karen Beardsley and her coauthors applied for funds from the UC Davis John Muir Institute of the Environment to develop a publication on the environmental impacts of each of the seven scenarios presented in the LUHA report. This was a natural progression since researchers worked closely with the work group members to develop the seven valley growth scenarios for 2050.

“The publication brings the scenarios to the next logical step by forecasting the environmental impacts.” said Beardsley. Using expert input from resource planners in federal, state, local and non-government organizations, LUHA members identified fourteen conservation priorities. Beardsley and her co-authors performed an analysis by comparing these priority layers with the projected human “footprint” from each growth scenario. Using data from geographic information systems, Beardsley and her coauthors compared locations of environmental priorities with targeted development areas. For each scenario she was able to estimate the expected loss of resources:

  • The highest loss of natural assets was from the scenario entitled “Prime Farmland Protection” which seeks to preserve farmland and designate growth outside farm areas.
  • The scenario “Status Quo,” representing no significant change in land use; “East-West Roads,” which encourages growth on east west highways; and “Exclusion Area” which preserves areas between I-5 and Hwy 99 from development; all represent a high losses of critical environmental resources.
  • “New Cities,” which depicts the creation of four new small cities of 250,000 near valley portals on land with low biological value; and “Great Cities,” which expands existing cities to 1 million plus with high density residential development, both have low impact on the environment.
  • The lowest impact on the environmental assets of the area is realized from the scenario called “Compact Growth,” which develops high density residential growth around current spheres of influence.       

The negative impacts identified in this analysis include loss of habitat for endangered and sensitive species like the kit fox; and destruction of habitats rich in diversity, such as vernal pools, historic lakebeds, wetlands, woodlands, grasslands and desert scrub. “The analysis of impacts to the environmental resources is made more difficult by the disconnected and isolated ecological fragments of land within the eight counties of the valley. In view of the valley’s staggering growth rates, including these impacts as part of the intelligent planning process is essential if these resources are to be preserved for the use of future generations,” stated Beardsley at the Great Valley Center conference in Sacramento.

The Information Center for the Environment is a program in the John Muir Institute of the Environment, a collaboration of UC Davis experts discovering solutions to complex environmental challenges.

The publication entitled “Policy Implications of Growth Modeling and Environmental Assessment in the San Joaquin Valley of California” can be downloaded at the John Muir Institute of the Environment’s Web site at http://johnmuir.ucdavis.edu/pdflibrary/whitepapers/beardsley-et-al.pdf.

Additional Information:

Media Contact(s):

  • Karen Beardsley, Information Center for the Environment, (530) 752-5678, kbeardsley@ucdavis.edu
  • Mike McCoy, Information Center for the Environment, (530) 754-9171, mcmccoy@ucdavis.edu
  • Sylvia Wright, UC Davis News Service, (530) 752-7704, swright@ucdavis.edu