Reservoir level and discharge data were collected for three Tennessee Valley Authority (TVA) dams (Chickamauga, Watts Bar and Douglas) on the Tennessee river in the Eastern Tennessee Seismic Zone (ETSZ). Earthquake catalog data was also collected for the ETSZ from 1980-2018. Well levels from 2 U.S. Geological Survey groundwater monitoring wells were also collected. Rainfall data were collected for the ETSZ. Reservoir, well and rainfall data were examined for correlation with earthquake occurrence rates. High Pearson correlation and anti-correlation coefficients (.7-.9) were obtained for the reservoir level and dam discharge volume rates vs monthly earthquake counts. Pearson correlation coefficients for rainfall and well level vs. monthly earthquake counts were small (.0-.2). A large difference in earthquake rates between the months of February (low rate) and April (high rate) over the 39 year study period was observed. The difference in earthquakes rates for February and April are statistically significant at the 95% confidence interval using the two sample Poisson rate test. The high correlations for the reservoir level and flow discharge vs. earthquake counts provides strong evidence of hydro-seismicity occurring in the ETSZ from seasonal fluctuations in reservoir level and discharge flow. / Master of Science / Reservoir level and discharge data were collected for three Tennessee Valley Authority (TVA) dams (Chickamauga, Watts Bar and Douglas) on the Tennessee river in the Eastern Tennessee Seismic Zone (ETSZ). Reservoir discharge and level data was collected for the three reservoirs. Also collected were rainfall data for the study area. This was provided by the TVA. Earthquake and well level data was collected from the USGS. High Pearson correlations for dam discharge and reservoir level vs. earthquake counts provided strong evidence of hydro-seismicity in the ETSZ.

A study of reproduction and spawning habits of the bluegill in a particular lake must include adequate samples for each period of the year. This will make it possible to determine the number of eggs in each spawn and the frequency of spawning. The number of spawns and average egg production for various sized fish shows the pattern of activity and makes possible further basic research.

Reservoir heterogeneities exhibit a wide range of length scales, and their interaction with various transport mechanisms control the overall performance of subsurface flow and transport processes. Modeling these processes at large-scales requires proper scale-up of both heterogeneity and the underlying transport mechanisms. This research demonstrates a new reservoir modeling procedure to systematically quantify the scaling characteristics of transport processes by accounting for sub-scale heterogeneities and their interaction with various transport mechanisms based on the volume averaging approach. Although treatments of transport problems with the volume averaging technique have been published in the past, application to real geological systems exhibiting complex heterogeneity is lacking. A novel procedure, where results from a fine-scale numerical flow simulation reflecting the full physics of the transport process albeit over a small sub-volume of the reservoir, can be integrated with the volume averaging technique to provide effective description of transport at the coarse scale. In a volume averaging procedure, scaled up equations describing solute transport in single-phase flow are developed. Scaling characteristics of effective transport coefficient corresponding to different reservoir heterogeneity correlation lengths as well as different transport mechanisms including convection, dispersion, and diffusion are studied. The method is subsequently extended to describe transport in multiphase systems to study scaling characteristics of processes involving adsorption and inter-phase transport. Key conclusions drawn from this dissertation show that 1) variance of reservoir properties and flow responses generally decrease with scale; 2) scaling of recovery processes can be described by the scaling of effective mass transfer coefficient (Keff); in particular, mean and variance of Keff decrease with length scale, similar in the fashion of recovery statistics (e.g., variances in tracer breakthrough time and recovery); 3) the scaling of Keff depends on the underlying heterogeneity and is influenced by the dominant transport mechanisms. To show the versatility of the approach for studying scale-up of other transport mechanisms, it is also applied to derive scaled up formulations of non-Newtonian polymer flow to investigate the scaling characteristics of the apparent viscosity and effective shear rate in porous media. / text

Data for a study of the benthic macroinvertebrates in Imperial Reservoir in Yuma County, Arizona was collected 1970-1973. Imperial Reservoir is an old, heavily sedimented reservoir on the lower Colorado River. An extensive dredging program revealed that the benthic habitat supported a low number of invertebrate species (four insects and two oligochaets) in comparison to other bodies of water. Probable reasons for the low number of species included high salinity, low organic detrital input into the reservoir, low habitat and substrate diversity, temporary low dissolved oxygen concentration, possible contamination with agricultural chemicals, and the remoteness of Imperial Reservoir from other aquatic environments. Within Imperial Reservoir the benthic macroinvertebrate community was restricted to more isolated, calm, side lakes which altogether made up only 23% of the entire surface area of the reservoir. Within these side lakes benthic macroinvertebrates were found primarily on mud substrate. Invertebrates were not found beneath dense stands of Najas marina, a rooted submersed macrophyte. Only two species of invertebrates appear to inhabit rocky substrates. Community analysis suggested that there were no large differences among most habitats where benthic invertebrates were found. A study of the microdistribution of each species of invertebrate indicated that there were two patterns of spatial dispersion: (1) taxa which bred continuously appeared to have no life history related change in dispersion; and (2) taxa which formed recognizable cohorts appeared to spread out from initial egg mass and dispersion changed with time from clumped to random. Secondary net production measures were made directly on predominant benthic invertebrates at two sites in Imperial Reservoir. Both sites had similar production values which were low when compared to production values from other bodies of water. Low benthic production in Imperial Reservoir was related to several environmental factors including high water temperature and temporary low oxygen concentration near the bottom during the summer, low input of organic detritus into the reservoir, and high predation on benthic invertebrates by fish. Collection and analysis of the stomach contents of the bass, bluegill and redear sunfish revealed that the smaller fish of a species were more dependent on benthic invertebrates for food. Large bass did not use benthic invertebrates as heavily as either bluegill or redear.

It was the purpose of this investigation to attempt to demonstrate if differences in eutrophic levels existed among selected areas of Garza-Little Elm, and to demonstrate the role that sediments play in affecting eutrophication.

A represa de Piracuruca está localizada no município de Piracuruca, a 3º58\'S e 41º40\'W, na região Norte do Estado do Piauí. A vegetação do entorno é do tipo cerrado, com solos ácidos e pobres em nutrientes. O seu uso é caracterizado pela pecuária extensiva e agricultura de subsistência. O presente estudo visa a caracterização da represa de Piracuruca considerando os fatores físicos e químicos da água e a comunidade zooplanctônica. As características físicas e químicas de um ambiente aquático são fundamentais para o conhecimento de seu funcionamento. Em termos de oxigenação da água, o epilímnio apresentou valores relativamente altos de oxigênio dissolvido e anoxia no hipolímnio, tanto em escala sazonal como interanual. Para a temperatura foram observadas pequenas amplitudes de variação e formação de termoclinas nas camadas superiores de epilímnio. Devido às características arenosas dos solos e a decomposição da matéria orgânica na represa, os materiais suspensos foram predominantemente caracterizados pela função inorgânica, nos períodos amostrados. As altas concentrações de fósforo, derivadas principalmente da decomposição da vegetação submersa não removida durante a fase de enchimento do reservatório, ocasionaram um elevado grau de trofia para o ecossistema. O zooplâncton foi composto por vinte e nove táxons de Rotifera, nove de Cladocera e três de Copepoda, não havendo diferenças significativas na composição dos táxons encontrados na região\"litorânea\" e na região limnética. Para o zooplâncton foi registrado um índice de diversidade relativamente alto, não ocorrendo, no entanto, as diferenças sazonais significativas em termos de abundância ou composição taxonômica. / Piracuruca reservoir is located on Piracuruca municipality at 3°58\'S and 41°40\'W in the region North of Piauí State. The surrounding vegetation is a savannah type called \"cerrado\", with acid soils, poor in nutrients. Landuse is characterized by extensive cattling and subsistence agriculture. The present work intends to do a limnological characterisation of Piracuruca reservoir, considering physical and chemical water factors and zooplanktonic community. Physical and chemical features of a water body are environment are important for its functioning understanding. Regarding water oxygenation, epiliminion had high dissolved oxygen content and anoxia acurred in the hypolimion, and interanual and seasonal scale. For temperature it was observed a small variation amplitude and thermocline formation in epiliminion superior layers. Due to soils sandy features the suspended matter was predominantly characterised by the inorganic fraction, in both periods. High phosphorus concentrations, originated mainly from decomposition of the submersed vegetation, not removed during the reservoir filling phase, caused a high trophy degree for the ecosystem. Zooplankton was composed by twenty-nine Rotifera taxa, nine Cladocera taxa and three Copepoda taxa; there were no significant differences among the taxa composition in littoral and limnetic region. Diversity indices for zooplankton community were relatively high and there were no relevant seasonal differences registered in abundance or taxonomic composition.

A represa de Piracuruca está localizada no município de Piracuruca, a 3º58\'S e 41º40\'W, na região Norte do Estado do Piauí. A vegetação do entorno é do tipo cerrado, com solos ácidos e pobres em nutrientes. O seu uso é caracterizado pela pecuária extensiva e agricultura de subsistência. O presente estudo visa a caracterização da represa de Piracuruca considerando os fatores físicos e químicos da água e a comunidade zooplanctônica. As características físicas e químicas de um ambiente aquático são fundamentais para o conhecimento de seu funcionamento. Em termos de oxigenação da água, o epilímnio apresentou valores relativamente altos de oxigênio dissolvido e anoxia no hipolímnio, tanto em escala sazonal como interanual. Para a temperatura foram observadas pequenas amplitudes de variação e formação de termoclinas nas camadas superiores de epilímnio. Devido às características arenosas dos solos e a decomposição da matéria orgânica na represa, os materiais suspensos foram predominantemente caracterizados pela função inorgânica, nos períodos amostrados. As altas concentrações de fósforo, derivadas principalmente da decomposição da vegetação submersa não removida durante a fase de enchimento do reservatório, ocasionaram um elevado grau de trofia para o ecossistema. O zooplâncton foi composto por vinte e nove táxons de Rotifera, nove de Cladocera e três de Copepoda, não havendo diferenças significativas na composição dos táxons encontrados na região\"litorânea\" e na região limnética. Para o zooplâncton foi registrado um índice de diversidade relativamente alto, não ocorrendo, no entanto, as diferenças sazonais significativas em termos de abundância ou composição taxonômica. / Piracuruca reservoir is located on Piracuruca municipality at 3°58\'S and 41°40\'W in the region North of Piauí State. The surrounding vegetation is a savannah type called \"cerrado\", with acid soils, poor in nutrients. Landuse is characterized by extensive cattling and subsistence agriculture. The present work intends to do a limnological characterisation of Piracuruca reservoir, considering physical and chemical water factors and zooplanktonic community. Physical and chemical features of a water body are environment are important for its functioning understanding. Regarding water oxygenation, epiliminion had high dissolved oxygen content and anoxia acurred in the hypolimion, and interanual and seasonal scale. For temperature it was observed a small variation amplitude and thermocline formation in epiliminion superior layers. Due to soils sandy features the suspended matter was predominantly characterised by the inorganic fraction, in both periods. High phosphorus concentrations, originated mainly from decomposition of the submersed vegetation, not removed during the reservoir filling phase, caused a high trophy degree for the ecosystem. Zooplankton was composed by twenty-nine Rotifera taxa, nine Cladocera taxa and three Copepoda taxa; there were no significant differences among the taxa composition in littoral and limnetic region. Diversity indices for zooplankton community were relatively high and there were no relevant seasonal differences registered in abundance or taxonomic composition.

Bull Run Watershed was set aside in late the 1800s as the water supply source for the City of Portland. Other than two dams being constructed, Reservoir #1 (1929) and Reservoir #2 (1962), development of the land had been minimal as public access was restricted. In the early 1960s, land management changed with increased road building and timber removal raising concerns about increased sediment discharge into the reservoirs. The objective of this study is to evaluate how much and how fast the sediment has accumulated in Reservoir #1, and to determine if the rate of sediment accumulation has changed over time. Three methods are utilized: 1) differencing map comparing pre- and postimpoundment sediment conditions, 2) analysis of tree-stumps on reservoir floor, and 3) gravity coring of reservoir sediment. Combining these methods, sediment volume is estimated between 254,000-422,000 cubic meters (332,000-552,000 cubic yards) and the rate of accumulation between 11.5-19.1 tonnes/km2/yr, reflecting a relatively low sediment yield rate. Two anomalous event-layers were identified in gravity cores collected. These are interpreted to be the 1964 flood and the 1972 North Fork Slide. Using these two events, sediment yield rate was divided into different historical segments: 15.33 (1930-1965); 43.62 (1965-1972); and 17.00 tonnes/km2/yr (1972-1993). The increase from 1965-1972 is attributed to either residual affects from the 1964 flood and/or changes in land management activities during this time. The source of the reservoir sediment is primarily from upper tributaries, with 20 percent being attributed to the anomalous events. Smaller amounts of sediment come from the reservoir side walls as lake levels raise and lower. Suspension and turbidity conditions in the reservoir are affected by the dynamics of the drainage system including seasonal fluctuations. Turbidity remains high at the upper reaches of the reservoir before settling out closer to the dam. Some sediment possibly leaves the reservoir over the spill-way or when water is removed for power production.

Wingecarribee and Fitzroy Falls Reservoirs are part of the Shoalhaven system within the Sydney metropolitan water supply network and are both shallow, well mixed, polymictic water bodies. After construction in 1973, land use activities within the catchments changed from low intensity grazing to more intensive practices such as dairying, particularly on the northern foreshore of Wingecarribee Reservoir, and vegetable farming around Fitzroy Falls Reservoir. The change in land use practice raised concerns about the possible impact on water quality of the reservoirs. This study sought to differentiate between the influence of catchment effects, inter-reservoir transfers and seasonality to enable an assessment of long term trends in water quality to be made. Data collected on a monthly basis by the Water Board between October 1973 and December 1985 were assessed and representative or 'indicator' variables for the different influences were selected. Classification of the phytoplankton to create sample clusters followed by discriminant analysis of the abiotic data were performed to rank the 'indicator' variables The classification analyses indicated that time of sampling was more important than site differences in determining clustering and that both Wingecarribee and Fitzroy Falls Reservoirs were well mixed and similar. The influence of chronological changes following the initial filling of the reservoirs, seasonality and inter-reservoir transfers were detected in the clustering patterns. Changes attributable to land use activities within the catchments were not detected. The reduction in concentrations of variables from high values following the initial filling of the reservoirs was the main influence regulating clustering between 1974 to 1982 and the influence of seasonality on clustering was most apparent during 1976 and 1978. The assessment of the influence of inter-reservoir transfers was restricted because of limited data. Seasonal periodicities and ongoing changes in the phytoplankton and physical and chemical data over the study period were assessed as a means of interpreting and verifying the analysis results.

Today, except for mathematical operations, our brain functions much faster and more efficient than any supercomputer. It is precisely this form of information processing in neural networks that inspires researchers to create systems that mimic the brain’s information processing capabilities. In this thesis we propose a novel approach to implement these alternative computer architectures, based on delayed feedback. We show that one single nonlinear node with delayed feedback can replace a large network of nonlinear nodes. First we numerically investigate the architecture and performance of delayed feedback systems as information processing units. Then we elaborate on electronic and opto-electronic implementations of the concept. Next to evaluating their performance for standard benchmarks, we also study task independent properties of the system, extracting information on how to further improve the initial scheme. Finally, some simple modifications are suggested, yielding improvements in terms of speed or performance.