Several methods have been developed for use in estimating the water quality loads associated with urban and agricultural landuses and practices. These include the use of sophisticated computer models, typically based on using pollutant loading and runoff functions, regression equations, load export coefficients (LECs), and event mean concentrations (EMCs). This research has examined the feasibility of using a simple EMC approach with the Kentucky Nutrient Model (KYNM). The thesis includes an extensive literature review of EMCs and a synthesis of recommended values for a range of typical urban and agricultural landuses. The thesis also includes an extensive literature review of potential BMPs along with a summary of the typical removal efficiencies and costs associated with each type of BMP. The research also explored the potential to use the results from multiple applications of site specific BMP models like the Source Loading and Management Model (WinSLAMM) in the development of general functional relationships that could then be used to evaluate BMP performance on a more site-specific basis. The developed EMC table and the associated BMP performance curves should provide valuable tools for use in better managing nutrient loads for urban and agricultural watersheds.

Karst bedrock conditions and deterioration of the lock and dam structures have resulted in significant leakage through, underneath, and around Lock and Dam No. 8 on the Kentucky River. During severe droughts, the water surface in Pool No. 8 has been observed to drop below the crest of the dam, resulting in water supply shortages and water quality issues for surrounding communities reliant on the pool. Presently, the primary purpose of Lock and Dam No. 8 is water supply. Pool No. 8 is currently where the cities of Nicholasville (Jessamine County, KY) and Lancaster (Garrard County, KY) draw their water. Due to the age and condition of the structures, and the criticality of the retained water supply, the project Owner commissioned a replacement dam to be built. One major component of the replacement dam was a foundation improvement program. The foundation improvement program was designed to address the karst bedrock conditions at the site. The foundation improvements included a secant pile cutoff wall and a double-row grout curtain. The grout curtain at Lock and Dam No. 8 was evaluated based on the metrics presently available.

Fluviokarst landscapes are dominated by both fluvial and karst features. Interpreting hydrologic pathways of fluviokarst can be confounded by the unknown connectivity of the various flow regimes. A combined discrete-continuum (CDC) hybrid numeric model for simulating the surface and subsurface hydrology and hydraulics in fluviokarst basins was formulated to investigate fluviokarst pathways. This model was applied to the Cane Run Royal Springs basin in Kentucky USA. A priori constraints on parameterization were avoided via multi-stage optimization utilizing Sobol sequencing and high performance computing. Modelling results provide evidence of hydrologic pathways dominated by fracture flow, epikarst transfer and runoff. Fractures in karst basins with high fracture-matrix permeability ratios may influence both springflow and streamflow. Swallet features can be as important as spring features as they are sink features in streamflow during hydrologic events. Inflections in spring hydrographs represent shifts in the surface-subsurface connectivity via the fractures, as opposed to shifts in dominant storage zones. Existing methods of dual- and triunal hydrograph separation of karst springflow may not be directly transferrable to fluviokarst springs. The numerical model herein has advantages of suggesting dominant pathways in complex terrane and highlighting unforeseen surface-subsurface connectivity. However, disadvantages include computational expense and previous site studies.

This dissertation represents the research and development of new concepts and techniques for modeling the knowledge about the many concepts we as hydrologists must understand such that we can execute models that operate in terms of conceptual abstractions and have those abstractions translate to the data, tools, and models we use every day. This hydrologic knowledge includes conceptual (i.e. semantic) knowledge, such as the hydrologic cycle concepts and relationships, as well as functional (i.e. procedural) knowledge, such as how to compute the area of a watershed polygon, average basin slope or topographic wetness index. This dissertation is presented as three papers and a reference manual for the software created. Because hydrologic knowledge includes both semantic aspects as well as procedural aspects, we have developed, in the first paper, a new form of reasoning engine and knowledge base that extends the general-purpose analysis and problem-solving capability of reasoning engines by incorporating procedural knowledge, represented as computer source code, into the knowledge base. The reasoning engine is able to compile the code and then, if need be, execute the procedural code as part of a query. The potential advantage to this approach is that it simplifies the description of procedural knowledge in a form that can be readily utilized by the reasoning engine to answer a query. Further, since the form of representation of the procedural knowledge is source code, the procedural knowledge has the full capabilities of the underlying language. We use the term "functional ontology" to refer to the new semantic and procedural knowledge models. The first paper applies the new knowledge model to describing and analyzing polygons. The second and third papers address the application of the new functional ontology reasoning engine and knowledge model to hydrologic applications. The second paper models concepts and procedures, including running external software, related to watershed delineation. The third paper models a project scenario that includes integrating several models. A key advance demonstrated in this paper is the use of functional ontologies to apply metamodeling concepts in a manner that both abstracts and fully utilizes computational models and data sets as part of the project modeling process.

Previous studies have identified water meter inaccuracy at low flow rates as a significant source of non-revenue flow for water systems; however a lack of available data makes it difficult to include low flow accuracy degradation in meter replacement plans. This thesis examines results from an extensive accuracy test program carried out at the Utah Water Research Laboratory on small water meters over a wide range of flow rates and at various levels of throughput. The study compares expected apparent losses of different types of water meters based on a flow profile and expected daily use for the State of California. By including an average composite charging rate, use of the method developed in this study can determine the meter replacement payback period for different meter types. The analysis contained in this document is intended as a guide to assist utility managers when developing meter replacement plans.

Three-dimensional scour propagation along offshore pipelines is a major reason to pipeline failures in an offshore environment. Although the research on scour in both numerical and experimental aspect has been extensive over the last three decades, the focus of the investigation has been limited to the two-dimensional aspect. The knowledge on three-dimensional scour is still limited. This dissertation presents the results of an experimental investigation on threedimensional scour along offshore pipelines in (1) steady currents (2) waves only and (3) combined waves and current. The major emphasis of the investigation is to investigate the propagation of the scour hole along the pipeline after the initiation of scour. Physical experiments conducted were used to quantify the effects of various parameters on scour propagation velocities along the pipeline. The problem of monitoring real time scour below a pipeline was solved by using specifically developed conductivity scour probes. Effects of various parameters such as pipeline embedment depth, incoming flow Shields parameter, Keuglegan- Carpenter (KC) number and flow incident angle to the pipeline on scour propagation velocities along the pipeline were investigated. The investigations clearly reveal that scour propagation velocities generally increase with the increase of flow but decrease with the increase of the pipeline embedment depth. A general predictive formula for scour propagation velocities is proposed and validated against the experimental results. There are still some common issues related to pipeline scour that is lacking in the literature to date. One of these issues is the effects of Reynolds number on two-dimensional scour beneath pipelines. A numerical approach was adopted to investigate the Reynolds-number dependence of two-dimensional scour beneath offshore pipelines in steady currents. A novel wall function is proposed in calculating the suspended sediment transport rate in the model. The effects of Reynolds number were investigated by simulating the same undisturbed Shields parameters in both model and prototype but with different values of Reynolds number in two separate calculations. The results revealed that scour depths for prototype pipelines are about 10~15% smaller than those for model pipelines. The normalized time scales was found to be approximately the same, and the simulated scour profiles for the model pipelines agree well with the experimental results from an independent study. The backfilling of pipeline trenches is also an important issue to the design and management of offshore pipelines. A numerical model is developed to simulate the self-burial of a pipeline trench. Morphological evolutions of a pipeline trench under steady-current or oscillatory-flow conditions are simulated with/without a pipeline inside the trench. The two-dimensional Reynolds-averaged continuity and Navier-Stokes equations with the standard k-e turbulence closure, as well as the sediment transport equations, are solved using finite difference method in a curvilinear coordinate system. Different time-marching schemes are employed for the morphological computation under unidirectional and oscillatory conditions. It is found that vortex motions within the trench play an important role in the trench development.

Hydrological observations are characterised by wet and dry cycles, a characteristic that is termed hydrological persistence. Interactions between global climate phenomena and the hydrological cycle result in rainfall and streamflow data clustering into wetter and drier states. These states have implications for the management and planning of water resources. Statistical tests constructed from the theory of wet and dry spells indicate that evidence for persistence in monthly observations is more compelling than at an annual scale. This thesis demonstrates that examination of monthly data yields spatially - consistent patterns of persistence across a range of hydrological variables. It is imperative that time series models for rainfall and streamflow replicate the observed fluctuations between the climate regimes. Monthly time series are generally represented with linear models such as ARMA variants ; however simulations from such models may underestimate the magnitude and frequency of persistence. A different approach to modelling these data is to incorporate shifting levels in the broader climate with a tendency to persist within these regimes. Hidden Markov models ( HMMs ) provide a strong conceptual basis for describing hydrological persistence, and are shown to provide accurate descriptions of fluctuating climate states. These models are calibrated here with a full Bayesian approach to quantify parameter uncertainty. A range of novel variations to standard HMMs are introduced, in particular Autoregressive HMMs and hidden semi - Markov models which have rarely been used to model monthly rainfall totals. The former model combines temporal persistence within observations with fluctuations between persistent climate states, and is particularly appropriate for modelling streamflow time series. The latter model extends the modelling capability of HMMs by fitting explicit probability distributions for state durations. These models have received little attention for modelling persistence at monthly scale. A non - parametric ( NP ) HMM, which overcomes the major shortcomings of standard parametric HMMs, is also described. Through removing the requirement to assume parametric forms of conditional distributions prior to model calibration, the innovative NP HMM framework provides an improved estimation of persistence in discrete and continuous data that remains unaffected by incorrect parametric assumptions about the state distributions. Spatially - consistent persistence is identified across Australia with the NP HMM, showing a tendency toward stronger persistence in low-rainfall regions. Coherent signatures of persistence are also identified across time series of total monthly rainfall, numbers of rain - days each month, and the intensities of the most extreme rain events recorded each month over various short durations, illustrating that persistent climate states modulate both the numbers of rain events and the amount of moisture contained within these events. These results provide a new interpretation of the climatic interactions that underlie hydrological persistence. The value of HMMs to water resource management is illustrated with the accurate simulation of a range of hydrologic data, which in each case preserves statistics and spell properties over a range of aggregations. Catchment - scale rainfall for the Warragamba Reservoir is simulated accurately with HMMs, and rainfall - runoff transformations from these simulations provide reservoir inflows of lower drought risk than provided from ARMA models. / Thesis (Ph.D.)--School of Civil and Environmental Engineering, 2006.

<p>The wave field in the Baltic Sea has been modelled for a two-year period with the spectral wave model HYPAS. There is a large seasonal variation in the field and a minor annual one, both reflect the wind variation in the area. Since the Baltic Sea is fetch limited, the dominant wind direction is important for the maximum wave heights.</p><p>By studying the modelled wave energy density in combination with bottom type maps, the effect of the wave field on the sediment surface is examined. Up to half the bottoms in the Baltic Sea are affected ~25% of the time. A statistical relation between wave energy density and bottom types is found for the Gulf of Riga, but in the rest of the area the sediment maps were to coarse. It is, due to this, not possible to say if the result is valid for the whole area or if it is site specific.</p><p>During resuspension events the remineralisation is increased since deposited organic material is reintroduced into the watermass and there exposed to higher levels of oxygen. This process could act as an increased regional source of nitrogen in nutrient budgets and thus influence the conditions for nitrogen fixation and perhaps explain some of the geographical differences in the nitrogen fixation rates.</p>

Simulation of the planing hull in waves has been addressed during the last 25 years and basically been approached by strip methods. This work follows that tradition and describes a time-domain strip model for simulation of the planing hull in waves. The actual fluid mechanical problem is simplified through the strip approach. The load distribution acting on the hull is approximated by determining the section load at a number of hull sections, strips. The section-wise 2-dimensional calculations are expressed in terms of added mass coefficients and used in the formulations of both inertia and excitation forces in the equations of motions. The modeling approach starts from the hypothetic assumption that the transient conditions can be modeled based on those section-wise calculations. The equation of motion is solved in the time-domain. The equation is up-dated at each time step and every iteration step with respect to the momentary distribution of section draught and relative incident velocity between the hull and water and catches the characteristic non-linear behavior of the planing craft in waves. The model follows the principles of the pioneering work of E. E. Zarnick differing on model structure and in details such as the modeling of the lift in the transom area. A major part of the work is concerned with experiments and evaluation of simulations with respect to performed model tests and to published experiment data. Simulations of model tests have been performed and comparisons have been made between measured and simulated time series. The link between simulation and experiment is a wave model which is based on a wave height measurement signal. It is developed and evaluated in the thesis. The conclusions are in favor of the 2-dimensional approach to modeling the conditions for the planing hull in waves and among further studies is evaluation of simulated loads and motions to full-scale trial measurement data.

The aim of this experimental study was to investigate the hydraulic conditions at which air-entraining vortices would form in front of horizontal intakes and to determine the ways of eliminating the formation of these vortices by testing anti-vortex devices. For these reasons, a series of experiments were conducted in an experimental setup composed of a reservoir having the dimensions of 3.10 m x 3.10 m x 2.20 m and a pump connected to the intake pipe. Within the reservoir, between the concrete side walls adjustable plexiglass side walls were placed to provide the desired wall clearance for the intake pipes. Six pipes of different diameters / 5 cm, 10 cm, 14.4 cm, 19.4 cm, 25 cm and 30 cm were horizontally mounted on the front side of the reservoir one by one, and for each case, a wide range of discharges was provided from the reservoir by the pump. Under symmetrical approach flow conditions and zero bottom wall clearance, the experiments were repeated for each intake pipe and the &ldquo / critical submergence depths&rdquo / for the tested discharges were determined. At some of the discharges, the effect of horizontal plates located on the top of the pipe entrance as anti-vortex devices on the elimination of the vortices was investigated. The measured critical submergence depths were related in dimensionless form to the relevant dimensionless parameters and empirical equations were derived. These equations were compared with similar ones available in the literature and it was shown that the agreement between them was quite good.