Stuff in the City: University Government Partnership to Build Hoarding Intervention Capacity

CPACS Urban Research Awards Part of the mission of the College of Public Affairs and Community Service (CPACS) is to conduct research, especially as it relates to concerns of our local and statewide constituencies. CPACS has always had an urban mission, and one way that mission is served is to preform applied research relevant to urban society in general, and the Omaha metropolitan area and other Nebraska urban communities in particular. Beginning in 2014, the CPACS Dean provided funding for the projects with high relevance to current urban issues, with the potential to apply the findings to practice in Nebraska, Iowa, and beyond

Influence of Las Vegas Wash density current on nutrient availability and phytoplankton growth in Lake Mead

Density currents are commonly formed in reservoirs because of temperature or salinity induced density differences between inflowing and receiving waters. Anderson and Pritchard (1951) were among the first to demonstrate this in their investigations of density currents in Lake Mead. They found that the Colorado River formed an underflow in Lake Mead during the winter, an overflow in the spring and an interflow in the summer and fall. Wunderlich and Elder (1973) have since described the hydromechanics of these types of flow patterns, and density currents have been reported for several other large reservoirs (Carmack et al. 1979, Johnson and Merritt 1979). The importance of density currents in determining circulation patterns in reservoirs has long been known (Anderson and Pritchard 1951), but only recently have studies demonstrated their significance as mechanisms for transport of heat (Carmack et al. 1979) and nutrients (Gloss, Mayer and Kidd 1980). The vertical distribution and degree of mixing of a density current can directly influence nutrient availability to phytoplankton in the euphotic zone. In this paper, we describe how another density current in Lake Mead, the saline, nutrient rich Las Vegas Wash inflow, affects nutrient availability and phytoplankton growth in Las Vegas Bay

The Effects of impoundments on salinity in the Colorado River

The increase in salinity of our western rivers has been identified as one of the most serious water quality problems in the nation. This is of special concern in the Colorado River where salinity has increased from pristine levels estimated at 380 mg/1 to present-day levels of 825 mg/1 at Imperial Dam. Flow depletions, associated with decreased runoff and increased evaporation and diversions, coupled with high salt loading from natural and man-created sources are considered the primary causes for rising salinity in the river. The urban and agricultural development projected to occur in the basin through this century could deplete flows by an additional 2 million acre-feet (2.5 x 109 m3 )/yr. Salinity models indicate that depletions of this magnitude will elevate total dissolved solids concentrations (TDS) to 1150 mg/1 at Imperial Dam. Since this would have an enormous economic impact on municipal and agricultural water uses, salinity control programs are being implemented in the basin to maintain TDS at or below the 1972 levels. Historical data for the Colorado River, however, indicate that TDS concentrations are not increasing as rapidly as the models predict. Despite the extensive development and large flow depletions that have already occurred in the basin, TDS concentrations in Grand Canyon and below Hoover Dam have not changed appreciably since monitoring began. Water quality monitoring has recently shown that TDS concentrations throughout the Lower Colorado River Basin have been decreasing since 1972. This is thought to be a transient phenomenon caused by changes in flow patterns, salt routing or possibly inundation of saline sources in the Upper Colorado River Basin following completion of Lake Powell and other impoundments during the 1960s. This might also reflect more permanent reductions in TDS due to changes in chemical processes operating in the impoundments. The U.S. Geological Survey (USGS) has monitored ion and TDS concentrations in the inflows and outflow of Lake Mead and Lake Powell since early impoundment. The purpose here is to present results of our analysis of the USGS salinity data and describe how these large impoundments have historically influenced ion and TDS concentrations in the Colorado River. The implications of these findings are discussed relative to current efforts to control salinity in the Colorado River Basin

Final Report for the DOE-BES Program Mechanistic Studies of Activated Hydrogen Release from Amine-Boranes

Effective storage of hydrogen presents one of the most significant technical gaps to successful implementation of the hydrogen economy, particularly for transportation applications. Amine boranes, such as ammonia borane H3NBH3 and ammonia triborane H3NB3H7, have been identified as promising, high-capacity chemical hydrogen storage media containing potentially readily released protic (N-H) and hydridic (B-H) hydrogens. At the outset of our studies, dehydrogenation of ammonia borane had been studied primarily in the solid state, but our DOE sponsored work clearly demonstrated that ionic liquids, base-initiators and/or metal-catalysts can each significantly increase both the rate and extent of hydrogen release from amine boranes under moderate conditions. Our studies also showed that depending upon the activation method, hydrogen release from amine boranes can occur by very different mechanistic steps and yield different types of spent-fuel materials. The fundamental understanding that was developed during this grant of the pathways and controlling factors for each of these hydrogen-release mechanisms is now enabling continuing discovery and optimization of new chemical-hydride based hydrogen storage systems

The Effects of limited food availability on the striped bass fishery in Lake Mead

The original range of striped bass (Morone saxatilis) was along the Atlantic Coast. They were introduced into the lower Sacramento River in 1879 and are now also found along the Pacific Coast. A landlocked striped bass fishery was established in Santee-Cooper Reservoir, South Carolina, in 1954, and they have since been introduced into numerous other reservoirs, including Lake Havasu, Lake Mead and Lake Powell on the Colorado River. Striped bass were introduced into Lake Mead in 1969 in response to declines in the largemouth bass (Micropterus salmoides) fishery that occurred during the 1960s and in order to further utilize the forage base of threadfin shad (Dorosoma petenense). Natural reproduction of striped bass was documented in 1973, and a highly successful fishery developed during the late 1970s. Striped bass comprised 40.1% of the total angler catch in 1979. The development of the striped bass fishery in Lake Mead was not without cost. A stocking program of rainbow trout (Salmo gairdneri) and other salmonid species was started in 1969. This was also initiated to utilize the surplus threadfin shad production. The trout fishery was considered good from 1970 to 1975, when they comprised 13 to 19% of the total angler catch. This declined to 1% in 1976, despite increased stocking. Food habit studies conducted during this period revealed that rainbow trout occurred in 23% of the striped bass stomachs. The decline in the trout fishery was attributed primarily to predation by striped bass. The occurrence of other gamefish species in striped bass stomachs was low, but threadfin shad comprised 50% of their diet. Striped bass are noted for their voracious appetites and their ability to exploit shad in limnetic areas of reservoirs. This resulted in over exploitation of shad in Santee-Cooper Reservoir, South Carolina. Shad production is closely linked to phytoplankton productivity because of their planktivorous feeding habits. Phytoplankton productivity in Lake Mead declined considerably after Lake Powell was formed in 1963, and most of the reservoir is now oligotrophic-mesotrophic. Shad in Lake Mead are, therefore, extremely vulnerable to possible over exploitation by striped bass. The purpose of this paper is to describe how rapid growth of the striped bass population altered the relative abundance of threadfin shad and how food limitation may be a factor in limiting future success of the fishery

Nutrient interactions among reservoirs on the Colorado River

Interactions among physical, chemical and biological processes in reservoirs can significantly alter the characteristics of the discharge (Neel 1963, Wright 1967, Hannan 1979) that, in turn, can influence the ecology of the river downstream .(Ward and Stanford 1979). Investigations of the Colorado River, system reveal that reservoir-induced changes in the river can also affect downstream reservoirs. The formation of Lake Powell, in 1963 was accompanied by reductions in suspended sediment and nutrient loading and changes in the seasonal temperature and discharge cycles of the Colorado River. In this paper, we evaluate how these changes have influenced the nutrient and trophic status of Lake Mead, the large reservoir located 450 km downstream from Lake Powell

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Pre-Impoundment Water Quality Study for the West Divide Project

Introduction: The U.S. Bureas of Reclamation is currently in the process of evaluating a number of water development projects in Southwest Colorado. As a part of the planning process the Bureasu has conducted a water qualtiy investigation, in cooperations with the UWRL, of the stream segments that will be affected by each project. The data collected in this study were used to evaluate the water quality of each stream segment with respect to various beneficial uses of water (agriculture, raw municipal water supply, protection of the aquatic biota) and will provide a baseline by which to assess the impact of each project. In addition, these data will be used in the process of site location, design and oeprations planning for reservoirs and other project features. This report includes only the results of the West Divide Project. Data were collected for three water quality stations associated with this project: Station #13: West Divide Creek Station #20: Lower Colorado River at Silt, Colorado Station #21: Upper Colorado River at Newcastle, Colorado Water quality data were collected during the period from May, 1977, through August, 1978. One sample was collected and analyzed during each month of the study except during June, 1977, when two samples were collected from some sites. The concentration of 49 water quality constituents was determined for each sample at the UWRL