The Sierra Nevada mountains of California and Nevada have experienced rapid population growth during the past three decades, more than doubling in population from 1970Ð1990. Human settlement patterns to accommodate this growth have been dominated by single-family homes constructed on large lots of one to five acres with on-site well water and septic disposal systems. This settlement pattern has resulted in significant road construction and landscape fragmentation in comparison with more compact development contiguous to existing urban areas. Global social, demographic, economic, and technological factors have made this pattern of exurban development more feasible and more likely in the future, creating the conditions for significant fragmentation. Other rural areas of ecological sensitivity are experiencing similar growth. As part of the Sierra Nevada Ecosystem Project, a GIS-based model of exurban population growth was developed to assess the implications of alternative development patterns for the landscape ecology of the Sierra Nevada mountains. The model relies on U.S. Census, county assessor, USGS topography, surface hydrology, SCS soils, road network, water supply, sewage collection and treatment, power and gas supply, vegetation, endangered species, and local land use planning/zoning data. This paper presents both the exurban population growth model and an analysis of the impact projected to result from alternative patterns of exurban development.
Timothy P. Duane
University of California
City and Regional Planning and Landscape Architecture
228 Wurster Hall #1850
Berkeley, CA 94720-1850
Telephone: 916-292-3053
Fax: 916-292-1339
Email: duane@ced.berkeley.edu
Karl Goldstein