Modeling Watershed Sensitivity to Climate Change in Systems Affected by Discharge of Mine Tailings

For more than a century, a large volume of gold-mining tailings was deposited in Whitewood Creek and the Belle Fourche River, tributaries to the Cheyenne River in western South Dakota. Much of it still remains, and field and historical evidence indicates continued remobilization of tailings-containing alluvium in these bedrock-dominated channels. Both long-term, natural fluctuations in climate and anthropogenically driven changes can impact regional precipitation, temperature, hydrologic patterns, and ecosystem functions. Such changes have the potential to affect both the transport and distribution of arsenic-laden sediments and mechanical erosion that can undermine the stability of channel-bed and overbank material. This study reevaluates published literature and simulates future climatic conditions with Global Change Models downscaled to hydrologic models to detect trends and determine if they differ from historical time series data or exhibit non-stationarity. Arsenic concentrations vary in solution with relatively small shifts in pH and Eh, allowing for the sorption/desorption on sediment and mobilization into the dissolved or aqueous phase. Published data suggest that the presence of competing anions are also important factors in controlling arsenic release. Carbonates in the alluvium and locally occurring bedrock control the formation of acidic conditions. This river system continually adjusts to historical and recent changes to achieve a “new equilibrium” from the cessation of mining discharge; geomorphic changes linked to regional continental glaciation; stream channel readjustment due to discharge velocity changes in the Oahe Reservoir; and channel instability. Knowing the relationship between streamflow and sediment transport and assessing a stream’s sediment transport capacity are important to planning and managing river corridor protection and restoration. These are also significant considerations in predicting potential exposure of contaminant sediments to human, ecological, and biological receptors. It appears climate change may be exerting an influence on hydroclimatic variables in the Lower Cheyenne River Basin, difficult to pinpoint in a qualitative assessment. In general, water resource managers should build resiliency into their designs to adaptably account for potential future impact of climate variability. Adviser: Dr. Shannon L. Bartelt-Hun

A system architecture and simulation environment for building information modeling in virtual worlds

The Peter Kiewit Institute (PKI) occupies a 192,000 square foot building on the University of Nebraska at Omaha’s (UNO’s) Pacific Street campus. PKI is home to approximately 85 faculty and 11 academic programs serving 1,800 students from two colleges: the University of Nebraska- Lincoln (UNL) College of Engineering and the UNO College of Information Science and Technology. In the summer of 2012, the research team wrote a paper summarizing a year’s worth of research concerning the integration of building information models and virtual worlds. The specific virtual world used was Science Applications International Corporation’s (SAIC’s) On- Line Interactive Virtual Environment (OLIVE). This research began when PKI students interested in modeling and simulation established the PKI Society for Computer Simulation International (SCS) Student Chapter and formed a research partnership with SAIC. Through this partnership, the team gained valuable experience with OLIVE and its many existing applications, including collaboration, training, education, and data visualization. It then became apparent that a potential additional application of OLIVE was architectural visualization. Using a virtual world to explore building plans before they are finalized was a significant improvement over traditional architectural renderings because the structure could be seen at any angle instead of at one fixed view point

Modeling Watershed Sensitivity to Climate Change in Systems Affected by Discharge of Mine Tailings

For more than a century, a large volume of gold-mining tailings was deposited in Whitewood Creek and the Belle Fourche River, tributaries to the Cheyenne River in western South Dakota. Much of it still remains, and field and historical evidence indicates continued remobilization of tailings-containing alluvium in these bedrock-dominated channels. Both long-term, natural fluctuations in climate and anthropogenically driven changes can impact regional precipitation, temperature, hydrologic patterns, and ecosystem functions. Such changes have the potential to affect both the transport and distribution of arsenic-laden sediments and mechanical erosion that can undermine the stability of channel-bed and overbank material. This study reevaluates published literature and simulates future climatic conditions with Global Change Models downscaled to hydrologic models to detect trends and determine if they differ from historical time series data or exhibit non-stationarity. Arsenic concentrations vary in solution with relatively small shifts in pH and Eh, allowing for the sorption/desorption on sediment and mobilization into the dissolved or aqueous phase. Published data suggest that the presence of competing anions are also important factors in controlling arsenic release. Carbonates in the alluvium and locally occurring bedrock control the formation of acidic conditions. This river system continually adjusts to historical and recent changes to achieve a “new equilibrium” from the cessation of mining discharge; geomorphic changes linked to regional continental glaciation; stream channel readjustment due to discharge velocity changes in the Oahe Reservoir; and channel instability. Knowing the relationship between streamflow and sediment transport and assessing a stream’s sediment transport capacity are important to planning and managing river corridor protection and restoration. These are also significant considerations in predicting potential exposure of contaminant sediments to human, ecological, and biological receptors. It appears climate change may be exerting an influence on hydroclimatic variables in the Lower Cheyenne River Basin, difficult to pinpoint in a qualitative assessment. In general, water resource managers should build resiliency into their designs to adaptably account for potential future impact of climate variability

The occurrence of illicit and therapeutic pharmaceuticals in wastewater effluent and surface waters in Nebraska

Passive samplers were used to develop semi-quantitative estimates of pharmaceutical concentrations in receiving waters influenced by wastewater effluent. The occurrence and estimated concentration of twenty illicit and therapeutic pharmaceuticals and metabolites in surface waters influenced by wastewater treatment plant (WWTP) discharge and in wastewater effluents in Nebraska were determined using Polar Organic Chemical Integrative Samplers (POCIS). Samplers were installed in rivers upstream and downstream of treated WWTP discharge at four sites and in a discharge canal at a fifth location. Based on differences in estimated concentrations determined from pharmaceuticals recovered from POCIS, WWTP effluent was found to be a significant source of pharmaceutical loading to the receiving waters. Effluents from WWTPs with trickling filters or trickling filters in parallel with activated sludge resulted in the highest observed in-stream pharmaceutical concentrations. Azithromycin, caffeine, 1,7-dimethylzanthine, carbamazepine, cotinine, DEET, diphenhydramine, and sulfamethazine were detected at all locations. Methamphetamine, an illicit pharmaceutical, was detected at all but one of the sampling locations, representing only the second report of methamphetamine detected in WWTP effluent and in streams impacted by WWTP effluent

Hydrogeology and water-quality conditions at the City of Olathe Landfill, east-central Kansas, 1990-93 /

Shipping list no.: 95-0040-P.Includes bibliographical references (p. 43-44).Mode of access: Internet