"Characterization, Monitoring and Modeling of GeoSystems" contains 135 papers that were presented at the 2008 GeoCongress, held in New Orleans, Louisiana from March 9-12, 2008. This Geotechnical Special Publication covers mechanical and chemical soil behavior, testing, and modeling. It presents innovations on subsurface characterization and monitoring, characterization of rocks, problematic soils and waste materials, and sensor technologies. Recent developments in numerical and computational geotechnics, emerging technologies, fate and transport modeling, uncertainty modeling, and micro- and environmental geomechanics are also discussed.