Geologic Hazards

Growth of population, communication and interdependence among countries has sharpened the impact of natural disasters. Not only have calamities and miseries been given wider publicity, but the realization has grown that through rational study and foresight much can be done to mitigate these hazards to life and social wellbeing. In this book we present a summary account of hazards which nowadays are usually classified as geological: earthquakes, faulting, tsunamis, seiches, vol canoes, avalanches, rock and soil slides, differential settlement and liquefaction of soil, and inundation. The book is aimed first at the general reader who is interested in studying the history of such hazards and examining ways that risk can be reduced even if all dangers cannot be eliminated. We also hope that the book will be useful to college students in introductory courses in geology, engineering, geography, country and urban planning, and in environmental studies. We have tried to bring out for the students the problems that remain to be solved.

Geologic hazards pose the greatest threat to human safety for any geotechnical undertaking, but it is ultimately the engineer's ability to recognize and cope with these hazards that will determine the safety of life and property. Armed with Geologic Hazards: A Field Guide for Geotechnical Engineers you will be able to properly recognize, understand

The purpose of these guidelines for investigating geologic hazards and preparing engineering-geology reports, is to provide recommendations for appropriate, minimum investigative techniques, standards, and report content to ensure adequate geologic site characterization and geologic-hazard investigations to protect public safety and facilitate risk reduction. Such investigations provide important information on site geologic conditions that may affect or be affected by development, as well as the type and severity of geologic hazards at a site, and recommend solutions to mitigate the effects and the cost of the hazards, both at the time of construction and over the life of the development. The accompanying suggested approach to geologic-hazard ordinances and school-site investigation guidelines are intended as an aid for land-use planning and regulation by local Utah jurisdictions and school districts, respectively. Geologic hazards that are not accounted for in project planning and design often result in additional unforeseen construction and/or future maintenance costs, and possible injury or death.

Geologic hazards are naturally occurring processes that present a risk to life and property. This report provides information for the Monroe City area, in Utah's central Sevier Valley, to reduce losses from geologic hazards. Surficial-geologic mapping provides the basis on which individual geologic hazards are identified and mapped. Alluvial-fan and basin-fill deposits cover most of the map area. Other deposits consist of colluvium, artificial fill, spring travertine, and volcanic bedrock. The geologic hazards maps show where hazards may exist. The maps should be used to inform citizens and developers of potential risks and for local government officials to make prudent land-use planning decisions. The maps are general, and site-specific studies are needed to demonstrate site suitability prior to development. Typical risk-reduction methods for these geologic hazards generally include avoidance or engineering design to reduce the risk to an acceptable level.

As a result of the landslides of 2005-06, Utah Governor Jon M. Huntsman, Jr., approved establishment of a working group to review the land-use-regulation process in Utah, recommend improvements, and identify how and where the State could assist. The Governor's Geologic Hazards Working Group (GHWG) was established in 2006 and met regularly from September 2006 through June 2007. This report highlights some of the 2005-06 landslides, reviews the establishment and activities of the GHWG, and presents the GHWG?s recommendations for reducing losses from geologic hazards.

This study contains 10 1:24,000 scale GIS based geologic hazard maps that include liquafaction, surface fault rupture, flood hazard, landslides, rock-fall, indoor radon potential, collapsible soils, expanisve soils, shallow bedrock and shallow groundwater potential. Also includes a 73 page accompanying report that describes the hazards and provides background information on data sources, the nature and distribution of hazards, and possible hazard reducation measures.