2008 Joint Meeting of The Geological Society of America, Soil Science Society of America, American Society of Agronomy, Crop Science Society of America, Gulf Coast Association of Geological Societies with the Gulf Coast Section of SEPM

Paper No. 5
Presentation Time: 2:35 PM

Evolution of the Holocene Alluvial Belts of the Lower Mississippi River Using Empirically Derived Palaeohydrology Equations


PROKOCKI, Eric W. and BLUM, Michael D., Geology and Geophysics, Louisiana State University, E 235 Howe-Russell Building, Baton Rouge, LA 70803, eproko1@lsu.edu

The geomorphology and Quaternary geologic history of the Lower Mississippi Valley (LMV) has been debated since the original work conducted by Harold N. Fisk in the 1940s. Roger T. Saucier compiled Fisk's work and created the second generation maps of the LMV, which have been widely used in studies of the LMV since their original publication. The following study reexamines the Holocene meander belt evolution of the LMV using palaeohydrology equations developed using the modern Mississippi River as an analog. Empirical relations are developed by measuring pre-levee construction meander scar characteristics and water-discharge data from gauging stations located along the modern Mississippi River. Four empirical equations were developed, and used to decipher the complexity of the evolution of the single thread meandering channel system of the LMV as it developed from the Pleistocene to early Holocene braided system. The four equations relate: Mean Annual Discharge vs. Bed Width, Mean Annual Discharge vs. Radius of curvature; 1.58(yr) Recurrence Flood Discharge vs. Bankfull Width, and the 1.58(yr) Recurrence Flood Discharge vs. Radius of Curvature.