Geologic hazards and adverse construction conditions, St. George-Hurricane metropolitan area, Washington County, Utah (SS-127)

By: W. R. Lund, T. R. Knudsen, G. S. Vice, and L. M. Shaw

The St. George-Hurricane metropolitan area is one of the nation?s fastest growing regions. As land well suited for development becomes increasingly scarce, urbanization has moved into less favorable areas where geologic hazards and geology-related adverse construction conditions are of concern. The Utah Geological Survey has prepared a GIS-based map folio containing 14 1:24,000-scale geologic-hazard and adverse-construction-condition maps for the St. George-Hurricane metropolitan area. Each map has an accompanying document that provides information on the nature of the hazard or adverse condition in the study area. The maps are an aid for general planning to indicate where site-specific studies are required. A GIS search application permits the maps to be queried by geologic hazard or adverse condition type and location, and produces a map and report on the hazards or adverse conditions of interest.

Geologic-hazard maps in the folio include surface faulting, liquefaction, flooding, landslides, and rock fall. Adverse-construction-condition maps include expansive soil and bedrock, collapsible soil, gypsiferous soil and bedrock, caliche, wind-blown sand, breccia pipes and paleokarst, shallow ground water, and piping- and erosion-susceptible soils. There is also a text document describing the earthquake ground-shaking hazard in the study area; however, data are insufficient to prepare a map.

Other Information:
Published: 2008
Pages: 88 p.
Location: Washington County