HR: 12:05h
AN: U52A-08    [Abstracts]
TI: Emergent Urban-Landscape Interactions in Mountain Catchments
AU: * Werner, B
EM: bwerner@ucsd.edu
AF: Complex Systems Laboratory, Institute of Geophysics and Planetary Physics, University of California - San Diego, La Jolla, CA 92093-0225 United States
AU: McNamara, D
EM: dmcnamara@ucsd.edu
AF: Complex Systems Laboratory, Institute of Geophysics and Planetary Physics, University of California - San Diego, La Jolla, CA 92093-0225 United States
AU: Kelso, A
EM: kelso@zinn.ucsd.edu
AF: Complex Systems Laboratory, Institute of Geophysics and Planetary Physics, University of California - San Diego, La Jolla, CA 92093-0225 United States
AU: Ipiktok, T
EM: ipiktok@zinn.ucsd.edu
AF: Complex Systems Laboratory, Institute of Geophysics and Planetary Physics, University of California - San Diego, La Jolla, CA 92093-0225 United States
AB: The margins of mountain catchments can offer attractive residential attributes, but development is subject to an array of significant hazards. The question of how urban expansion and natural processes interact as a system to produce long-term, emergent patterns of coupled human-landscape dynamics is addressed in a model that treats natural processes on intermediate time scales on a cellular grid and urban processes using agent-based models of markets and local/regional government. In the model, shrubland vegetation grows between fires, wildfires consume vegetation and residences and promote erosion, and landslides, floods and sediment-laden debris flows damage or destroy residences. Developer agents build developments whose size and location are based on projected profits; homeowning agents buy houses based on projected appreciation and attributes such as view and commute distance. Based on their predicted effect on tax revenues, government agents approve developments; mitigate fires with prescribed burns; mitigate landslides, floods and debris flows with slope stabilization, debris basins, reservoirs and channel stabilization and entrenchment; and suppress fires. Initial investigation of the model has focused on long-time-scale behavior of the urban-wildland boundary. Mitigation measures filter out short, small-amplitude fluctuations in this boundary. As the relative time scales and interaction magnitudes characterizing natural processes, development and government action are varied, a nominally stable boundary becomes unstable to irregular, long period fluctuations that can be spatially complex. The role that market externalities play in producing nonoptimal states will be discussed. Supported by the Andrew W. Mellon Foundation.
DE: 1803 Anthropogenic effects
DE: 1815 Erosion and sedimentation
DE: 1824 Geomorphology (1625)
DE: 1884 Water supply
SC: Union [U]
MN: 2004 AGU Fall Meeting