Urban effects on flood plain natural hazards: Wolf River, Tennessee, USA

The Wolf River and its flood plain in the City of Memphis and Shelby County, TN, have been extensively altered since the flood plain underwent liquefaction during the earthquakes of 1811–1812. Flood plain denudation and aggradation (primarily cut and fill) are documented by subtracting flood plain surface elevations obtained in the 1940s, 1965, 1988, and 2001. The resultant maps, cross-sections, and histograms illustrate the complex history and extreme changes that the flood plain has undergone. As a consequence of these post-1940s changes, liquefaction potential of the flood plain is now very complex; the flood plainʹs area has locally been diminished by approximately 50%, thereby requiring remapping of the areas that will be inundated by 100- and 500-year floods; and entrenchment of the Wolf River and its flood plain may have increased connectivity between Wolf River water and Shelby Countyʹs aquifer.