Morphological and process dynamics of the Lower Mississippi River

摘要: This thesis uses data sets at a range of spatial and temporal scales to examine the geomorphological response Lower Mississippi River engineering management. During twentieth century geomorphology has been transformed by series modifications improve flood control aid navigation. These have included steepening longitudinal profile removal most sinuous bends, fixing river constant planform through extensive bank stabilisation, regulating sediment movement channel system dike field construction. Prior these modifications, adjusted its morphology satisfy large-scale flow resistance requirements. However, this mode adjustment effectively removed adjustments are now restricted long cross-sectional form. Morphological analysis reveals that responded intervention two principal scales: vertical changes in elevation bed reach-scale; increasing bedform sub-reach scale adjustments. mutual consistent with water surface post-modification period noted Biedenharn Watson (1997). morphological process dynamics shorter timescales shows remains difficult explain. is because behaviour any scale, location within an alluvial channel, product complex spatially-distributed feedbacks between operating processes multiple morphology. general significance terms research design detecting complexity each adjustment, forming linkages dependent on taking into account all possible degrees freedom, applying complementary analytical techniques.