AuthorHanson, Randall Tyler,1953-
Subsidences (Earth movements) -- Arizona -- Tucson Basin.
Subsidences (Earth movements) -- Arizona -- Avra Valley.
Committee ChairNeuman, Shlomo P.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractGround-water declines of several feet per year since the 1940's induced aquifer-system compaction and land subsidence of as much as 0.5 foot in the Tucson basin and 1.1 feet in Avra Valley. Aquifer-system compaction is affected by layering, hydraulic diffusivity, preconsolidation stress, and stress history of the aquifer system. Layering at extensometer sites can be categorized into three general groups that typify the fine- and coarse-grained layering within the Fort Lowell Formation and upper Tinaja beds. A one-dimensional compaction model was used to simulate aquifer-system compaction of less than 0.1 foot. Elastic and some inelastic specific storage values are comparable to previous estimates. Parts of the aquifer systems appear to be in transition from predominantly elastic to inelastic compaction. Water-level declines since 1940 at the six modeled extensometer sites are within an estimated preconsolidation-stress threshold of 50 to 150 feet. The simulations were most sensitive to reduction of initial preconsolidation stress and least sensitive to changes in aquifer specific storage.
Degree ProgramHydrology and Water Resources