Thesis (Ph. D.)--Washington University, 1908. / Cover title. Offprint: Annual report of the Missouri Botanical Garden, 19th.

Thesis (Ph.D.) University of Wisconsin--Madison, 1928. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 163-167).

In 1879 Congress created the Mississippi River Commission (MRC) to develop and coordinate federal flood control policy for the Lower Mississippi River. Through 1927, that Commission clung stubbornly to a "levees-only" policy that was based on the mistaken belief that levees alone could be effective in controlling the flood waters of the Mississippi River. When the levees failed--and they occasionally did--the MRC responded by raising and strengthening the system but refused to adopt a more comprehensive program, one which would include outlets and reservoirs. Finally, a disastrous flood in 1927 forced the abandonment of levees-only and the adoption of a comprehensive plan for the Lower Mississippi River. Predictably, the MRC faced heavy criticism following the failure of its highly-touted levee system in 1927. While certainly the Commission was culpable, there was plenty of fault to go around and a plethora of mitigating circumstances. Developing a plan for achieving adequate flood control along the lower Mississippi River constituted what was probably the most difficult and complex engineering problem ever undertaken by the U. S. Government. Additionally, there were innumerable political and financial constraints that worked to shape MRC policy. This study will endeavor to tell the story of the MRC from its earliest origins through the landmark 1928 Flood Control Act, and, in the process, give evidence to the reality that the Commission did not function independently. As an organization, it relied upon outside forces for its membership, for its jurisdiction, and for the appropriations necessary to carry out its policies. Significantly, these forces were politically driven and did not always, or even often, share the MRC's priorities for the Lower Mississippi River. Even so, the MRC accomplished a great deal in its efforts to protect the Valley from moderate floods, to improve the navigability of the Mississippi River, and to expand significantly the body of knowledge available on the "Father of Waters."

1 examined the temporal and spatial distribution of total ammonia nitrogen (TAN) and un-ionized ammonia (NH,) in sediment pore water and compared the temporal and spatial patterns of TAN and NH, in overlying surface water with those in pore water, to determine if they were reaching concentrations known to be deleterious to fingernail clams. Pore water was obtained by core extraction and subsequent centrifugation. TAN and NI-I3 in pore water were measured from May through December 1994, at ninety two sites in pool 8, upper Mississippi River, to a depth of five centimeters below the sediment-water interface. TAN and NH3 in pore water were significantly different among sampling dates; with the greatest concentrations occurring in the summer months. Tan and N1-I3 in pore water was significantly greater in impounded open water and backwater side channel habitats and least in main channel border habitat. Tan and NH3 in surface water were significantly less than those in pore water from all of the habitats studied. Analysis of sediment substrate physical features, found that fingernail clam density and occupance were correlated to texture, with fingernail clams preferring silt loam and loam textures. Analysis of the data determined fingernail clams have a preference for particular water depths. It was found that a positive correlation exists between the occurrence and abundance of may flies and fingernail clams. Additionally, this study found a positive correlation between the density of dead fingernail clams (as per empty shells) and the abundance of live fingernail clams. Sites that contained a mean NI-I, concentration below 36 ug/L possessed the largest numbers of fingernail clams. When the mean un-ionized ammonia was above 36 ug/l, fingernail clam density declined precipitously-- 36 ug/L NH3 is the concentration demonstrated to inhibit growth of fingernail clams in laboratory studies. Mean concentrations of NH, in pore water at sites containing fingernail clams was 40 ug/L and ranged from 3 to 100 ug/L. At sites where fingernail clams were nonexistent, NH3 ranged from 3 to 375 ug/L with a mean of 57 ugfL. Mean un-ionized ammonia concentrations at sites containing fingernail clams were significantly different from and consistently lower than sites without fingernail clams. / Department of Natural Resources and Environmental Management

The Upper Mississippi River is in interest to river managers and biologists' dues to its vast ecosystem and past anthropogenic impacts. In order to help restore the river to its once natural state, river managers and biologists need a strong understanding of the hydrodynamics of the system. A two-dimensional hydrodynamic model was developed in Pool 8 of the Upper Mississippi River and utilized for river management applications. The model was constructed using SMS 10.0 grid generation software and processed with SRH-2D software. SRH-2D used Manning's roughness coefficients to calibrate the model to observed water surface elevation data collected by the USGS. The model was validated to an observed water surface elevation profile and percent discharge through 17 transects within the model. The calibrated and validated model was used for river management and biological applications; hypothetical island, drawdown scenarios, residence time study, and habitat suitability assessment. The results showed that the two-dimensional hydrodynamic model could accurately represent a hypothetical island within the lower pool, simulate drawdown scenarios, develop stream traces for particle tracking and residence time calculation, and the creation of habitat suitability maps based on field data. The completion of these applications with the two-dimensional model shows the efficiently and accuracy of the model, and how two-dimensional numerical models are important tools in bridging the gap between engineers and scientists.

Thesis (M.S.)--University of Wisconsin -- La Crosse, 1976. / Includes bibliographical references (leaves 72-76).

Published also as Thesis (Ph. D.)--University of Pennsylvania, 1906. / Includes bibliographical references (p. 153-160).

Thesis (M.S.)--University of Missouri, School of Mines and Metallurgy, 1949. / Vita. The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed July 12, 2010) Includes bibliographical references (p. 50-51).

Thesis (M.S.)--University of Wisconsin -- La Crosse, 1985. / Includes bibliographical references (leaves 56-59).

The trends of degradation and aggradation are measured in this study for the Lower Mississippi River. Historical riverbed elevation and stage data from the past hundred years were used from six gages in order to measure changes in riverbed gradation. It was found that using stage data to measure gradation changes is a superior method to using riverbed elevations, due to stage data’s reliability, length of record and daily measurements. Degradation in the Lower Mississippi River was seen during the