Browsing by Subject "Sedimentation"

Now showing 1 - 4 of 4
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    Assessment of Stormwater Best Management Practices
    (University of Minnesota, 2008-04) Anderson, James L.; Asleson, Brooke C.; Baker, Lawrence A.; Erickson, Andrew J.; Gulliver, John S.; Hozalski, Raymond M.; Mohseni, Omid; Nieber, John L.; Riter, Trent; Weiss, Peter; Wilson, Bruce N.; Wilson, Matt A.; Gulliver, John S.; Anderson, James L.
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    Data supporting Inhibition of the Growth of Harmful Algal Bloom-forming Freshwater Cyanobacteria by Clay
    (2022-03-14) Yang, Judy Q; Tomaska, Katherine R; Wei, Guanju; tomas098@umn.edu; Tomaska, Katherine R; Yang Research Group: Environmental Transport Lab
    This dataset contains cell density measurements and confocal images of Microcystis Aeruginosa. The raw data from hand counting cells under a microscope with a hemocytometer is included, as well as the calculated cell density based on the hemocytometer measurements. The bacteria cells were grown in one of three growth conditions. Each growth condition was simulated in three different flasks. For each date, the cell densities of identical growth conditions were averaged. Cell densities for each date and growth condition were subsequently plotted with error bars to determine any trends. Additionally, data on the environmental conditions of cell growth are included on dates when the measurements were taken. The physical interactions between cyanobacteria and clay particles were visualized using a confocal laser scanning microscope (Nikon C2 plus). Each image is around 2048 by 2048 pixels at a resolution of 0.08 um/pixel. We used a 20X objective magnification. A sequence of images was taken at 10-second intervals for 5 minutes. The laser used for excitation has a wavelength of 488 nm (FITC) and the emission wavelength is 525 nm.
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    Non-local theories of geomorphic transport: from hillslopes to rivers to deltas to the stratigraphic record
    (2012-09) Ganti, Naga Vamsi Krishna
    Landscapes are shaped by the interplay between tectonics and climate. The mass fluxes associated with the physical and chemical processes acting across the landscape involve the production and transport of sediment and solutes from the uplands to the lowlands. The processes operating on the Earth's surface dictate the selective long-term preservation of the history of these processes in the geological record. Acknowledging the stochastic nature of the processes that drive the evolution of the landscapes at various time scales involved is essential for building predictive models of sediment transport on the Earth's surface. However, traditional models often do not acknowledge the high variability of the driving forces, broad scales of motion involved and the heavy-tailed nature of events that shape the landscapes. This thesis research challenges existing thinking and puts forth a new class of macroscopic sediment transport models which take into account the probabilistic structure of the processes that shape the landscapes. A new class of macroscopic sediment flux models that are based on non-local theories, where sediment flux is not only a function of local hydro-geomorphic quantities but is a linear function of the space-time history of the system, are introduced. The unifying goal underlying this work is to develop sediment transport models that capture the extreme heterogeneity of the involved processes over a large range of scales, consider the presence of extreme fluctuations that arise due to the climatic forcing, and the spatial heterogeneity of landscapes that affects sediment production, storage, movement and delivery and to study how these surface dynamics are preserved in the Earth's geological record.
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    Sediment Control Log Performance, Design, and Decision Matrix for Field Applications
    (Minnesota Department of Transportation, 2019-05) Chapman, John; Wilson, Bruce; Holmberg, Kerry; Deering, Emily
    Significant time and money are currently being expended in the purchase and installation of sediment control logs. These logs often fail because of poorly understood performance limits and improper installation. This project investigated the performance limits by determining the flow and sediment removal characteristics of different types of logs. The physical characteristics and flow rates per project area were evaluated with twelve different logs. The densities and flow rate of materials in these logs varied between 0.035 gm/cm3 and 1508 ft /min for wood fiber to 0.269 gm/cm3 and 208 ft/min for compost. Flow rates were predicted using a power function of density with fair accuracy (r2=0.64) and predicted with good accuracy using saturated conductivity (r2=0.87) or capillary moisture content (r2=0.81). A sediment flume was constructed and used to evaluate sediment removal and failure rates. One log with three replicates of each type of material was tested. There was a positive, power function relationship between percent finer and mean log capture (r2 = 0.91). Field information was collected and used in conjunction with hydraulic and sediment data to develop selection guidelines for sediment control logs. Educational materials were prepared for workshops.