Science Application for Risk Reduction (SAFRR)
The Science Application for Risk Reductioon (SAFRR) estimates consequences of natural hazard disaster scenarios as a strategy to increase community resiliency, a community’s ability to cope with the effects of a disaster. SAFRR was initiated in 2006 as Multi-Hazards Demonstration Project (MHDP) in southern California but in 2012 the Associate Director of the Natural Hazards Mission Area expanded the scope of the project nationwide under SAFRR. This website offers insight on past, present and future research contributions toward SAFRR projects from the USGS Western Geographic Science Center, as well as information on the researchers themselves.
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Hazards Vulnerability Team
The risk of a future natural disaster is a function not only of the hazards but also of the vulnerability of individuals and communities that occupy hazard-prone areas. This team of researchers focuses on developing new methods for assessing and communicating community vulnerability to natural hazards. Research includes community vulnerability to tsunamis (Oregon, Washington, California and Hawaii), volcanoes (Mount Rainier and Mount Hood), hurricane storm surge (Florida) and climate-change-enhanced coastal hazards (California, Oregon and Washington coasts).
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Dasymetric Mapping Techniques: GIS-Based Tool & Analysis
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Spatial analysis of populated centers is necessary in order to conceptualize urban growth patterns essential for land-use planning and urban-growth modeling and natural hazard mitigation. Cartographic representation of human population distributions and socioeconomic information is commonly displayed using decennial census information using choropleth mapping techniques. However, these data are aggregates of geographic units (census tracts or block groups) whose boundaries do not always reflect the natural distribution of human populations. A dasymetric mapping technique is one potential solution for mapping population density relative to residential land-cover. Dasymetric mapping depicts quantitative areal data using boundaries that divide the area into zones homogenous land use/land cover, with the purpose of uncovering the statistical surface of population density. We have used the dasymetric mapping technique to enhance population representation for multiple areas. The 9-county San Francisco Bay Area was the pilot area for testing data inputs and the associated GIS-tool. The method was then applied to areas in the Pacific Northwest (Clatsop Co., and Clackamas Co., Oregon) for risk and vulnerability studies in the event of natural disasters.
4D Micro-Piston Motion of Halemaumau Lava Lake Surface Measured with Ground-Based Tripod LiDAR, Kīlauea, Hawaii
We measured decimeter-scale oscillations in the elevation of the Halemaumau lava lake (HLL) surface at Kīlauea Volcano, Hawaii, during a sequence of ground-based Tripod-LiDAR (T-LiDAR) laser scans September 13-14, 2012. Geodetically measuring elevational changes of a dynamic lava lake surface has inherent risks and technical challenges, including the ability to see the lake surface through the volcanic gases. We successfully penetrated most of the dense volcanic gases from the rim of the HLL using the Optech LR laser scanner 1-micron (1064 nm) laser (a wavelength that is not attenuated by water) to measure elevation changes of the surface of the active lava lake 164 meters below the scanner. We found that the average elevation of the entire lava lake surface oscillated with an average 10-cm amplitude across the HLL with increased amplitude (2-3 times larger) proximal to the downwelling portion of the lake. A temporal power-spectrum analysis of the T-LiDAR point cloud resolved an 8.4-second primary oscillation frequency with secondary frequencies at 3.3-second intervals from the primary (1.8, 5.1, 8.4, 11.7 seconds). Preliminary analysis of the seismic spectra shows a peak in the seismic signal at 7.8 seconds (0.13 hz) for the same time period. Qualitative assessment of time-lapse video of the lava lake surface visually confirms that the lava lake rises and falls about every 8 seconds with superimposed smaller-amplitude elevation changes approximately every 3 seconds. We suggest the term micro-pistoning to distinguish this behavior from the larger-scale gas pistoning events at Kīlauea that take place over several minutes (Patrick, M. et al, Bull Volcanol, V73(9)pp 1179-1186, 2011).
Contact Gerald Bawden with questions.