Safe in the 'Hood:  Earthquake Preparedness in Midcity Los Angeles

Abstract:  Is it possible to demonstrate a link between a pilot public awareness program for earthquake-related education and an increase in community safety, preparedness, and loss prevention efforts? This paper describes a pilot earthquake education, preparedness and mitigation project, the "ANNA-SCEC Earthquake Watch," funded in part by the University of Southern California Neighborhood Outreach nonprofit corporation and Southern California Earthquake Center, a National Science Foundation Science and Technology Center. The yearlong project targeted residents in a neighborhood located in the heart of Los Angeles. Together they cohosted presentations by earthquake experts at monthly neighborhood association meetings, created a neighborhood earthquake response and recovery plan, learned how to start earthquake-related small businesses, and conducted a public earthquake safety fair that attracted hundreds of residents and local media coverage. They distributed published information on earthquake preparedness and leveraged available funds to help other neighborhoods start similar programs. Preproject and postproject research was conducted to document the effectiveness of the project.

GIS-Based Estimation of Slope Stability

Abstract:  In this paper a decision support system is presented, which integrates the technology of geographical information systems in evaluating slope stability. A dynamic tool has been developed in ARC/INFO 7.0.1 Macro Language, the "Landslide Hazard Assessment Tool," which produces safety factor contours giving, as an output, a landslide hazard zonation map. The factors contributing to the manifestation of the phenomenon have been studied as well as the geomorphologic and quantitative information referring to the geotechnical parameters. To represent and interactively examine the results, a series of thematic maps have been created, using this overlay concept of geographical information systems. The study area is located in Vouraikos Valley, in northern Peloponeese, Greece. This particular area has been selected in order to test the model in an area strongly affected by landslides, belonging to the neotectonic regime of the Gulf of Corinth. The final conclusion is that proper implementation of engineering geological information can decrease the geohazard vulnerability of infrastructure. Such a model could be most helpful in the stage of decision making in the construction industry.

Lessons from Grand Forks:  Planning Structural Flood Control Measures

Abstract:  In the spring of 1997, the Red River Valley experienced a traumatic flood event that inundated 80% of Grand Forks, N.D., and arguably inflicted the largest economic damage per capita ever suffered by an American city and certainly far greater losses that cannot be measured in dollars. By probing what happened, this study found that the losses were made much larger by sequential surprises. For reducing surprises, integrated physically based weather-hydrologic-hydraulic modeling can quantify maximum flows and stages as well as extreme scenarios during floods in real time to provide "worst case" as well as "most probable" stages. It can also be used to structure forecasts around thresholds used in flood fighting decisions and to structure hazard mapping around optional configurations of structural measures and building patterns. It is particularly important to implement contingency planning for levee failure. Stochastic hydrologic modeling can be used to stimulate preparedness and reduce surprise.

Estimation of Volcanic Hazards from Tephra Fallout

Abstract:  The goal of probabilistic volcanic hazard assessment is to translate complex volcanological data and numerical models into practical hazard estimates for communities potentially affected by volcanic eruptions. Probabilistic volcanic hazard assessment quantifies volcanic hazards and illustrates uncertainties about the magnitude and consequences of volcanic activity. Planning based on probabilistic volcanic hazard assessment has the potential of mitigating the effects of volcanic eruptions when they occur. This paper presents an approach developed to estimate volcanic hazards related to tephra fallout and illustrates this approach with a tephra fallout hazard assessment for the city of LeoŽ n, Nicaragua, and the surrounding area. Tephra fallout from eruptions of Cerro Negro volcano has caused damage to property and adverse health effects and has disrupted life in this area. By summarizing the geologic and historical records of past eruptions of Cerro Negro on a probability tree, it is shown that the inhabitants of LeoŽ n can expect >1 cm of tephra accumulation from approximately 30% of eruptions, and >4 cm of tephra accumulation from approximately 9% of eruptions of Cerro Negro volcano. This historical record is augmented with simulations of tephra dispersion that estimate the likelihood of tephra accumulation given a range of eruption magnitudes and that map the expected distribution of tephra over a broader region. An upper limit value of 0.5 m is calculated using the tephra dispersion model. Without a fundamental change in the eruptive behavior of Cerro Negro, tephra accumulation in LeoŽ n is not expected to exceed this value.