Master of Science / Department of Computing and Information Sciences / Mitchell L. Neilsen / The United States Department of Agriculture (USDA) is currently researching the effectiveness of various earth dam designs and their ability to prevent erosion. This report utilizes experimental results from the USDA experimental hydraulic engineering research unit to develop computational fluid dynamics models using OpenFOAM. Several variations of smooth and stepped dam models are created and analyzed with OpenFOAM on multiple cores using Message Passing Interface. In this report, seven dam designs are analyzed to extract flow velocities and pressures and animations. This data and OpenFOAM models are helpful for determining potential erosion conditions.

Doctor of Philosophy / Department of Geography / Melinda Daniels / Great Plains rivers are unique systems that vary from large, continental scale, to small intermittent streams with grain sizes that range from bedrock to cobbles to silt. These rivers have been subject to widespread hydrologic alteration both within the channel and the watershed, which has resulted in an alteration in their hydrologic and geomorphic regimes. Although there is an acknowledgement of this alteration, to date there has not been a synthesis of the hydrology of Great Plains rivers or of their longitudinal morphologies. Chapters in this dissertation provide, to my knowledge, the first comprehensive analyses of the hydrology and morphology of Great Plains rivers over a range of spatial and temporal scales. In the first study, I found that there was no uniform pattern of hydrologic alteration throughout the Great Plains, which is likely attributable to variable system-specific reservoir management objectives, land use changes, and climatic regimes over the large area the Great Plains encompass. Results of this study are the first to quantify the widespread hydrologic alteration of Great Plains rivers following impoundment. In the second study, I found an apparent decoupling between local moisture conditions and streamflow in intermittent prairie streams. Results of this study used statistical models to identify relationships between flow intermittence, mean annual flow, and flood flow characteristics with moisture to characterize flow in an intermittent prairie stream. In the final study, I found that the downstream trends in hydraulic geometry and substrate characteristics of the Ninnescah River were consistent with the expected trends proposed by hydraulic geometry and substrate theories. However, there were points that deviated from the expected trends, most notably where a substantially large tributary enters the Ninnescah River and as the Ninnescah River approaches the Arkansas River, and causal explanations for these deviations were explored. Results of this study are, to my knowledge, the first of its kind to assess the longitudinal hydraulic geometry and substrate characteristics of a large sand-bed river over a large spatial scale. To our knowledge, there have been no comparable studies exist that attempted to describe hydrologic and geomorphic characteristics of prairie streams.

Master of Science / Department of Computing and Information Sciences / Mitchell L. Neilsen / In recent years, headline news has been overwhelmed with stories about dam and levee failures including the 2005 levee breaches in New Orleans and the 2006 Kaloko Damfailure in Hawaii that resulted in seven deaths. Since 2000, state and federal agencies have reported 92 dam failures in the United States to the National Performance of Dams Program. Incidents such as these have brought both national and worldwide attention to the need for improved flood warning systems and breach prediction tools for dam embankment and levee failures. (G. J. Hanson, 2010) IESIMBA 2012 is an upgraded version of SIMBA, which has been upgraded from VB6 to C#.NET. The Microsoft Windows-based SIMplified Breach Analysis software (SIMBA) was developed by the USDA Agricultural Research Service in cooperation with Kansas State University. The software was developed for the purpose of analyzing internal erosion, earth embankment breach test data and extending the understanding of the underlying physical processes of breach of an overtopped earth embankment. It is a research tool that is modified routinely to test the sensitivity of the output to various sub-models and assumptions. This software is a test version for use in validation testing of the simplified breach model based on stress and mass failure driven headcut movement. It runs under Microsoft Windows 98SE, Windows 2000, NT, XP, or Vista. The following Input Screens are used to guide the user through development of input data sets.  Model Properties , Dam Profile , Structure Table, Spillway Rating and Hydrograph Data After an input data set has been entered, the data is saved and simulation can be performed on the data stored in memory at any time by selecting Build option. Input and output files are stored in a fixed ASCII text format. The results of the simulation can be viewed in graphical format which are of interest to the researchers at Oklahoma State University, Stillwater by selecting View option.

Master of Science / Department of Geology / Saugata Datta / With the ever-rising atmospheric concentrations of CO₂ there arises a need to either reduce emissions or develop technology to store or utilize the gas. Geologic carbon storage is a potential solution to this global problem. This work is a part of the U.S. Department of Energy small-scale pilot studies investigating different areas for carbon storage within North America, with Kansas being one of them. This project is investigating the feasibility for CO₂ storage within the hyper-saline Arbuckle aquifer in Kansas. The study incorporates the investigation of three wells that have been drilled to basement; one well used as a western calibration study (Cutter), and the other two as injection and monitoring wells (Wellington 1-28 and 1-32). Future injection will occur at the Wellington field within the Arbuckle aquifer at a depth of 4,900-5,050 ft. This current research transects the need to understand the lateral connectivity of the aquifers, with Cutter being the focus of this study. Three zones are of interest: the Mississippian pay zone, a potential baffle zone, and the Arbuckle injection zone. Cored rock analyses and analyzed formation water chemistry determined that at Wellington there exists a zone that separated the vertical hydrologic flow units within the Arbuckle. This potential low porosity baffle zone within the Arbuckle could help impede the vertical migration of the buoyant CO₂ gas after injection. Geochemical analysis from formation water within Cutter indicates no vertical separation of the hydrologic units and instead shows a well-mixed zone. The lateral distance between Cutter and Wellington is approximately 217 miles. A well-mixed zone would allow the CO₂ plume to migrate vertically and potentially into potable water sources. Formation brine from Cutter was co-injected with supercritical CO₂ into a cored rock from within the Arbuckle (7,098 ft.). Results show that the injected CO₂ preferentially preferred a flow pathway between the chert nodules and dolomite. Post reaction formation chemistry of the brine showed the greatest reactivity occurring with redox sensitive species. Reactivity of these species could indicate that they will only be reactive on the CO₂ plumes front, and show little to no reactivity within the plume.

Master of Science / Department of Geology / Saugata Datta / Mass poisoning of arsenic (As) has affected roughly 60 million people in the Bengal Basin (Bangladesh and West Bengal, India) and 43 million people alone in West Bengal. Elevated levels of Manganese (Mn) is another alarming issue in the groundwaters of this region (MCLs: As<10µg/L and Mn< 0.4mg/L). Four locations in Murshidabad district (south-central part of Bengal Basin) were chosen for this current study. Among the 4 locations, two of them showed high concentration of As (>50 - 4622µg/L; 2009 survey) and they are Beldanga: 23° 56'N& 88°15'E and Hariharpara: 24°3.68'N & 88° 21.63'E. On the other hand: Nabagram (24°12.08'N & 88°13.29'E) and Kandi (23°58.6'N & 88°6.68'E) demonstrated less dissolved As (<10µg/L) in groundwaters. Study areas were located to the west (Nabagram, Kandi) and east (Beldanga, Hariharpara) of the river Bhagirathi, a tributary of the river Ganges, flowing N-S through the district of Murshidabad. Eastern side of the river is occupied by grey colored Holocene sediments and western side has more oxidized orangish-brown Pleistocene sediments. Comparative study of major water quality parameters between these sites revealed high As (10-1263µg/L) and low Mn (0.1-1.3mg/L) in the areas like Beldanga, Hariharpara while low As (0-15µg/L) and higher Mn (0.2-4.2mg/L) in Nabagram and Kandi. The pH range for high and low As areas were 4.5-7.8 and 5.1-8.2 respectively. Phosphates showed values <0.04-2.21mg/L in high As areas and <0.08-2.52mg/L in low areas whereas Cl- values were higher within low As areas (29-200mg/L) and lower within high As areas (3.9-78.4mg/L). Fe(t) and Fe2+ values at high and low As areas were 0-13.5mg/L, 0.01-0.11mg/L and 0-1.4mg/L, 0.04-0.06mg/L respectively. δ18O and δD results revealed that monsoonal precipitation is the major recharge source in this area with some input from the surficial waterbodies as ponds in shallower depths within high As areas. The total As extracted from core sediments in these areas do not show much difference: total As in high and low As areas ranges from 6.4-18 mg/kg. Sequential extraction results revealed that majority of the sediment bound As is present in residual phases (>40%). DOC in groundwaters in high and low As areas were 1.5-3.2 and 0.5-1.3mg/L respectively and they had positive correlation with As within the depth profiles. Dissolved organic matter (DOM) characterization studies indicated that microbial proteins (Tyrosine and Tryptophan) are the major components in the groundwaters in the low As region, whereas high As area groundwaters tend to have higher content of humic DOM (A and C). Cl/Br molar ratio of high As wells were low compared to the low As wells. Current study revealed the importance of organic matters (and not the mineralogy of the sediments) both in sediments and groundwaters in controlling the release of As from sediment, at least in the shallow parts of Bengal delta aquifer and microbial mediated reductive dissolution of FeOOH in the presence of organic matter is the major mechanisms by which sediment bound As (<50m depth) is released into the groundwater. The darker organic matter rich sediments (OM both sediment bound and anthropogenically derived) existing at the depth range 20m-50m with reducing environment persisting in both high and low As areas are possible reasons for elevated levels of As in this region.

Doctor of Philosophy / Department of Agronomy / P.V. Vara Prasad / Agriculture is the largest (90%) consumer of all fresh water in the world. The consumptive use of water by vegetation represented by the process evapotranspiration (ET) has a vital role in the dynamics of water, carbon and energy fluxes of the biosphere. Consequently, mapping ET is essential for making water a sustainable resource and also for monitoring ecosystem response to water stress and changing climate. Over the past three decades, numerous thermal remote sensing based ET mapping algorithms were developed and these have brought a significant theoretical and technical advancement in the spatial modeling of ET. Though these algorithms provided a robust, economical, and efficient tool for ET estimations at field and regional scales, yet the uncertainties in flux estimations were large, making evaluation a difficult task. The main objective of this study was to evaluate and improve the performance of widely used remote sensing based energy balance models, namely: the Surface Energy Balance Algorithm for Land (SEBAL), Mapping Evapotranspiration at high Resolution and with Internalized Calibration (METRIC), and Surface Energy Balance System (SEBS). Data used in this study was collected as part of a multi-disciplinary and multi-institutional field campaign BEAREX (Bushland Evapotranspiration and Agricultural Remote Sensing Experiment) that was conducted during 2007 and 2008 summer cropping seasons at the USDA-ARS Conservation and Production Research Laboratory (CPRL) in Bushland, Texas. Seventeen high resolution remote sensing images taken from multispectral sensors onboard aircraft and field measurements of the agro-meteorological variables from the campaign were used for model evaluation and improvement. Overall relative error measured in terms of mean absolute percent difference (MAPD) for instantaneous ET (mm h[superscript]-[superscript]1) were 22.7%, 23.2%, and 12.6% for SEBAL, METRIC, and SEBS, respectively. SEBAL and METRIC performances for irrigated fields representing higher ET with limited or no water stress and complete ground cover surfaces were markedly better than that for dryland fields representing lesser ET and greater soil water deficits with sparser vegetation cover. SEBS algorithm performed equally well for both irrigated and dryland conditions but required accurate air temperature data. Overall, this study provides new insights into the performance of three widely used thermal remote sensing based algorithms for estimating ET and proposed modifications to improve the accuracy of estimated ET for efficient management of water resources.