bluuebunny/crossref_metadata_2025 huggingface dataset:
A Review of Desalination Processes and Product Water Costs
Authors: Savage W. F.
Published: February 2008

At the present time the Office of Saline Water is conducting research and development in three basic desalination process areas. These are distillation, membrane, and crystallization. Processes within these areas include multistage flash distillation, vertical tube evaporation, vapor compression, reverse osmosis, electrodialysis, and vacuum freezing. The Office of Saline Water has in operation for developmental purposes, plants with capacities up to approximately 2.5 million gallons per day. These plants are located at five major test stations in the United States. On the basis of test results, analytical studies, and supporting investigations, water costs have been reduced significantly over the past five years. Technological developments have resulted in a 25% reduction in water costs for distillation processes desalting seawater and a reduction by a factor of 3 for reverse osmosis processes desalting brackish water considering a fixed plant size. Coupling of improved system technology with increasing plant size results in water costs that are foreseen to be competitive with alternate means of supplying freshwater to major water consuming areas.
Acquisition and Machine Processing of Saline Water Data from Southeastern New Mexico and Western Texas
Authors: Hiss W. L.
Published: February 2008

Approximately 20,000 saline water analyses obtained chiefly from oil companies and related service companies operating in the Delaware basin of southeastern New Mexico and western Texas were indexed to the Permian Basin Well Data System (PBWDS) magnetic tape file, coded, punched into tabulating cards, and stored on magnetic tape for computer operations. Location and operator indexes prepared from the PBWDS file were absolutely essential to efficient machine data processing operations. Extensive manual and computer error checks for duplication and accuracy were made to eliminate data errors resulting from the following: poorly located or identified samples; nonrepresentative or contaminated samples; mistakes in coding, reproducing, or keypunching; laboratory errors; and inconsistent reporting. The original 20,000 analyses considered were reduced to approximately 9000 representative analyses. Costs of acquisition and establishment of the data file approximated $5.00 per usable record. The compiled data were used in a study of the saline water resources of the Permian Artesia group and Capitan and San Andres limestones in southeastern New Mexico and western Texas.
Estimating Expected Values for Monotone Samples
Authors: Maddock T. , Crosby D. S.
Published: February 2008

New expected value estimates for monotone sample data can be produced while using the technique to produce a consistent covariance matrix.
Numerical Solution to the Convective Diffusion Equation
Authors: Oster C. A. , Sonnichsen J. C. , Jaske R. T.
Published: February 2008

A numerical solution to the convective diffusion equation is discussed. The case examined treats a conservative waste or pollutant, although the system is flexible enough to accommodate nonconservative substances. The numerical approximation appears stable and can be extended to include analysis of an n‐dimensional array.
Cost of Pumping Irrigation Water in Arizona: 1891 to 1967
Authors: Martin William E. , Archer Thomas
Published: February 2008

The historical record of the cost of pumping groundwater in Arizona is examined. Measures used are the cost per acre‐foot per foot of lift, the cost per acre‐foot, the water cost per acre for important crops, and the total water cost per farm for representative general crop farms. Costs are presented in actual dollars and dollars adjusted by GNP implicit price deflators. Whereas pumping depths have been rising rapidly, costs per acre‐foot per foot of lift have been falling, adjusted costs per acre‐foot have been almost constant, and per acre costs and total farm costs relative to both total costs and total returns have fluctuated throughout the time period examined, sometimes being lower but often being higher than costs at the present time.
Some Observations on the Effect of Wind Induced Thermal Mixing
Authors: Lakshman G.
Published: February 2008

Wind induced thermal mixing in a pond or slough influences the diurnal variation in the water surface temperature. This, in turn, greatly affects the rate of evaporation from the water surface. The maximum diurnal rise in the water temperature depends on the total duration of sunshine, the maximum rise in air temperature above the initial water temperature, and the wind speed. Sheltering a pond may increase the rate of evaporation under certain conditions.
Splash Amounts from Waterdrop Impact on a Smooth Surface
Authors: Mutchler Calvin K. , Larson Curtis L.
Published: February 2008

The mechanics of raindrop splash erosion of soil were investigated by using waterdrops impacting at terminal velocity onto various depths of water over smooth glass. Splash weight produced by waterdrop impact varied with waterdrop diameter D and surface water depth d. For a smooth hard surface, predicted splash in terms of waterdrop weight was zero at d/D = 0 and increased to a maximum at d/D of 0.14 and 0.20 for D = 0.559 cm and 0.296 cm, respectively. The influence of greater depth became relatively insignificant at a depth of about three drop diameters.
Optimal Use of Coupled Leaky Aquifers
Authors: Saleem Z. A. , Jacob C. E.
Published: February 2008

Aquifers enclosed or confined by sediments that impede or retard the vertical movement of groundwater generally leak. A stochastic dynamic programing model for the optimal operation of a composite system of two coupled leaky aquifers and a surface water subsystem is formulated and applied to the Roswell basin in New Mexico. The optimal operating policies for the two coupled aquifers of the basin are influenced by the values added to the basin by different crops, by the amounts of water in storage in the two aquifers, by the discount factor, and by mutual leakage of the aquifers. Some of these factors tend to increase whereas others tend to decrease the operating policy. The resultant of all these factors determines the final operating decision rule. The magnitude and direction of leakage are determined by the relative storages in the aquifers. Coupled aquifer systems should be considered for conjunctive use only.
Alternative Oxygenation Possibilities for Large Polluted Rivers
Authors: Whipple William , Yu Shaw L.
Published: February 2008

The idea of induced aeration of polluted rivers is gaining acceptance, prototype equipment having been installed on the Miami River in Ohio and on the Ruhr River in Germany. Previous analysis and reports have indicated the general feasibility of aeration on small rivers. This paper describes tests of aeration equipment on a major river, the Delaware Estuary, and discusses transfer efficiency, suitable aerator system design, and cost comparisons. Navigational considerations and deeper, more turbulent water cause design requirements for large rivers to differ considerably from the requirements for small rivers. Reinforced aerators at the surface appear favorable for uncrowded river areas, but air diffusers on the bottom appear more practicable and comparably economical for port areas. Diffusers can be placed only on channel margins and anchorage areas, but dispersion studies indicate that the oxygenated water will still reach the center of the river within a reasonable distance. The cost of adding one unit of dissolved oxygen by aeration devices appears to be just about one‐fourth that of adding it by officially approved waste treatment only. There are possibilities of lowering costs further by using oxygen diffusers. Institutional barriers that make it difficult to plan and develop pollution control alternatives such as river aerators are discussed.
Fluorescent Dyes, Their Uptake and Translocation in Plants
Authors: Donaldson D. E. , Robinson T. W.
Published: February 2008

Of seven fluorescent dyes tested, rhodamine WT (RWT) and pontacyl brilliant pink (PBP) were the only two found to be suitable for tracer studies of water movement in plants. The results indicate that RWT is superior to PBP. The dyes were introduced in the aqueous form into the root zone of plants and were rapidly absorbed and transported to the leaves. The dosages were 1, 2, and 5 grams of dye per 32 kg of soil. With the largest dosage, the dye could be observed visually in the leaves. The concentrations of dye per gram of plant tissue ranged from 5 μg of PBP in oleander plants to 323 μg of RWT in fir plants. The time that elapsed from introduction of the dye into the soil until its detection in the leaves varied from 4 to 24 hours. Neither RWT nor PBP had produced any observable adverse effects when the plants were inspected up to 160 days after injection. Interference by the plant material in measuring the dye concentration was not a problem.
Improvements in the Finite Difference Solution of Two‐Dimensional Dispersion Problems
Authors: Lawson D. W.
Published: February 2008

Two modifications of Shamir and Harleman's two‐equation scheme for the finite difference solution of two‐dimensional dispersion problems are presented. These modifications improve both the accuracy and the efficiency of the solution. Shamir and Harleman's one‐equation scheme is more efficient than the improved two‐equation schemes, but it is not as accurate.
Sensitivity of the Solution for Heat Flux or Evaporation to Off‐Diagonal Turbulent Diffusivities
Authors: Yeh Gour‐Tsyh , Brutsaert Wilfried
Published: February 2008

In most previous studies of three‐dimensional turbulent diffusion in the lower atmosphere, it was assumed that the principal axes of the diffusivity tensor coincide with the x direction of the mean wind, with the vertical z, and with the lateral y [Sutton, 1934; Monin, 1959; Laikhtman, 1964; Yeh and Brutsaert, 1971]. Thus the diffusivity was taken as a diagonal tensor with components Kxx, Kyy, and Kzz. However recent experimental evidence [Zubkhovskii and Tsvang, 1966; Wesely et al., 1970] and theoretical analysis [Lettau, 1952; Matsuoka, 1961; Gee and Davies, 1964; Brutsaert, 1970] have suggested that the principal axes of the diffusivity tensor do not coincide with the vertical and the mean wind direction but are tilted and that there is an additional diffusivity, namely an off‐diagonal component Kxz = Kzx.
Identification of Mathematical Models for DO and BOD Concentrations in Polluted Streams from Noise Corrupted Measurements
Authors: Koivo A. J. , Phillips G. R.
Published: February 2008

The numerical values of parameters in the mathematical model describing the dissolved oxygen (DO) and biochemical oxygen demand (BOD) concentrations (e.g., the reaeratio.n coefficient and the BOD removal coefficient) are determined in a systematic manner so that a best fit to the noise corrupted DO data is obtained asymptotically. The goodness of the estimates is evaluated by the squared difference between measured DO concentrations and concentrations calculated from the mathematical model. A stochastic approximation algorithm of the Robbins‐Monro type is applied for computing the parameter values in a sequential manner. The algorithm converges in the mean square sense to the parameter value that furnishes a local minimum for the average of the error criterion. The procedure is illustrated by several numerical examples. Because of the sequential nature of the algorithm, savings in computer time as well as in the required memory capacity are obtained.
Analysis of Variations in Dissolved Oxygen in an Impoundment in Central Illinois
Authors: Kothandaraman V. , Evans Ralph L.
Published: February 2008

Spectral analysis is employed to investigate the nature of variations in dissolved oxygen concentrations in Lake Bloomington by using an 18‐month record of weekly observations. At the deepest portion of the lake, seasonal changes with a periodicity of 4 months are found to be significant; this corroborates findings based on chemical water quality changes. The results of spectral analysis of DO records at 0.61‐meter depth of different stations in the lake are similar. The upper layers of the entire lake respond alike to the changes in DO concentrations. Long‐term and random variations in the observations are thought to be the predominant features of the DO record. The limiting depth of the epilimnetic zone in the lake, as defined by temperature and DO, appears to be about 6.10 meters.
Streamflow and Sediment Deposition in the Lower Columbia
Authors: Norgaard Richard B.
Published: February 2008

The value of water in each of its uses and the physical production function describing the possible combinations of uses must be known to manage a river optimally. One aspect of the physical production function on the Columbia River, the relationship between the state of the navigation channel and streamflow characteristics, was derived by regression analysis on each of the 28 bars between Vancouver, Washington, and the Pacific Ocean. The regression equations were used to predict dredging costs for three hypothetical streamflow patterns. The predictions suggest that dredging costs are quite sensitive to relatively small differences in the magnitude and character of the annual streamflow pattern.
Physical Simulation of Infiltration Equations
Authors: Lin Wender , Gray Don M.
Published: February 2008

A method of using laminar (capillary) flow models for synthesizing the infiltration process on physical hydrologic models is described. The equations defining laminar flow in capillary tubes and between parallel plates were derived for several different geometric configurations representing horizontal, vertically downward, vertically upward, an radial flow. The theoretical equations for the different configurations are shown to be analogous in functional form to the theoretical and empirical infiltration equations used to define the time variation in the infiltration rate of a soil. The results from several tests conducted on capillary tubes were in close agreement with those obtained from the theoretical equations. Thus it was concluded that capillary flow models can be used to synthesize the infiltration process on physical models.
A Technique for Smoothing River Flows during Hydroelectric Power Production
Authors: Tattle R. B. , List E. J.
Published: February 2008

When several hydroelectric power plants are on the same river system severe fluctuations in flow can occur because of variations in electric power demand. A technique is developed by which the power demand on the river system can be met while at the same time the river flow is kept as smooth as possible downstream from a selected dam in the system. The smoothing problem is solved by devising a linear programing formulation that includes constraints on output and storage for each hydroelectric plant and also satisfies continuity equations. The method is applied successfully to an existing three‐dam hydroelectric system.
Effects of urbanization on storm water runoff quality: A limited experiment, Naismith Ditch, Lawrence, Kansas
Authors: Angino Ernest E. , Magnuson Larry M. , Stewart Gary F.
Published: February 2008

The extensive use of storm water runoff as an auxiliary source of water will probably be justified economically in the near future, providing the water is of proper quality. Water samples were collected for dry weather periods, rainstorms, and snowmelts and evaluated for pH, residue (total, volatile, filterable), chemical oxygen demand (COD), biochemical oxygen demand (BOD), NO3, Cl and total alkalinity. Most changes in water quality are not so great as to be apparent by inspecting the data. Statistical analysis is necessary for testing the more subtle chemical relationships. Suspended solids concentrations during snowmelt and rainstorms do not differ; NO3 is relatively high, COD averages 34 ppm (parts per million). Occasional pollutants include Cr+6, 27 ppm, Br, 5 ppm. and Cl, 2150 ppm; Pb concentrations in suspended solids as high as 0.55% were found. The general extent to which urban storm runoff contributes to pollution of the streams is yet to be completely determined.
An approach to the design of statewide or regional groundwater information systems
Authors: Winter Thomas C.
Published: February 2008

The design of water information or basic data systems must be flexible enough to provide information and data for a broad range of interests from national to local. The system must satisfy the need for information for accounting, surveillance, and areal synthesis purposes. The network is designed by identifying specific needs in terms of maps, analyses, and studies that will provide the basic knowledge for understanding each particular phase of the groundwater system. Each specific need is then analyzed with respect to whether it will provide information on accounting, surveillance, or areal synthesis. If a particular type of map, analysis, or observation can serve any of these three functions, a network of data collection or a program of studies is outlined in detail that will provide the information needed. The method of design necessitates the establishment of accuracy levels for maps, the density of data points, confidence limits, and so forth. The information system should be under the general guidance of a single agency, but much of the work and responsibility to carry out the details of the system must be shared by a number of agencies.
Data needs for predicting problems caused by the use of subsurface reservoirs
Authors: Stallman Robert W.
Published: February 2008

There is an observable trend toward the use of subsurface reservoirs for storing different fluids. This trend is rapidly changing the picture of investigative programing for evaluating such reservoirs. Historically, studies were focused chiefly on the consequences of the withdrawal of fluids. Projecting the changing emphasis toward the broader use of storage capacity, one should expect problems arising from the injection of fluids to attain a similar significance. The injection of fluids with dissolved substances of kinds and in concentrations incompatible with the rocks can cause thermal and chemical stresses in addition to the more prosaic pressure stress. All three types of stress can produce changes: (1) in the reservoir, (2) of the land surface, and (3) of structures on the land surface. Subsidence, seismic response, water quality degradation, and plugging of the pore space are already recognized as undesirable consequences of withdrawal and injection. Earth scientists are not yet fully cognizant of the need to define such responses in the subsurface quantitatively, and therefore planners cannot become fully aware of the total cost of various alternatives for using the sub‐surface. Hopefully, research emphasis and data collection practices will be altered to answer successfully the new and more complex questions.
Variance spectra of short duration rainfall in time and space
Authors: Hershfield David M.
Published: February 2008

Variance spectra for rainfall amounts were determined for time series composed of 5‐, 10‐, 30‐, and 60‐minute rainfalls from selected storms at individual gages in dense networks. Space series were developed from rainfalls at fixed intervals along transects in the direction of storm movement. The areas considered in the analysis range in size from less than 1 mi2 to 1000 mi2 and cover several rainfall regimes. Diagrams display such relationships as the correlation coefficient as a function of distance between rain gages and time series duration, the autocorrelation coefficient as a function of lag and time series duration, and the power spectral density as a function of wave number for both the time and the space series.
Snowmelt energy exchange in the Lake Superior Region
Authors: Santeford Henry S. , Alger George R. , Meier John G.
Published: February 2008

A 2‐year study of snowmelt in the Upper Peninsula of Michigan is summarized. The major results are (1) that although it was frozen in early winter, the ground thawed and remained unfrozen as snow accumulated from mid‐February on; (2) that the unfrozen ground allowed the production and infiltration of ground melt, which gave rise to a winter base flow twice that of summer; and (3) that a standard equation for predicting air‐snowpack moisture exchange was inadequate, especially when condensation occurred. It is proposed that this latter discrepancy is due to the occurrence of condensation just above, rather than at, the snow surface, so that the latent heat is released largely to the air rather than to the snowpack.
Effects of serially correlated inflows on reservoir behavior
Authors: Perrens Stephen J. , Howell David T.
Published: February 2008

The effects on reservoir yield of the magnitude of the serial correlation of inflows are determined for a highly simplified situation in which inflows are normally distributed and do not exhibit seasonal variation. The results are obtained by simulation with large samples and are presented in the form of graphs showing the relationships between dimensionless variables.
Model for estimating regional water needs
Authors: Schaake John C. , Major David C.
Published: February 2008

A model for estimating water flow requirements by geographic area, economic sector, and water quality type has been constructed and implemented for the North Atlantic regional (NAR) water resources study. The estimates are produced by rules that operate on the basic input assumptions regarding the future regional product, the per capita income, the population, the distribution of economic activity, the use of water, and technology. The collection of rules includes an economic input–output model, a regression estimator for publicly supplied municipal and industrial water use, and a variety of arithmetic operations. These rules are imbedded in an information system that accepts input information in a problem‐oriented format and provides output information as selected by the user in an annotated form suitable for use in final reports. The information system provides options for editing data, storing and retrieving data sets, and comparing input and output information for any two runs.
Impact of systems techniques on the planning process
Authors: Major David C.
Published: February 2008

The major impacts of systems techniques on the planning process in the North Atlantic regional water resources study are described. The techniques discussed are an input‐output‐based demand projection model and a mathematical programing supply model. The impacts discussed relate to the coordination and control of the planning process, the consideration of multiple objectives, the assessment of uncertainty, the efficiency of planning, the scope for the exercise of judgment, and the opportunity for a planning process continued beyond the final report. The writer concludes that the impact of systems techniques has been positive and recommends that no major water resource planning efforts be undertaken in the future without a commitment to the use of systems techniques.
A note on the Nile
Authors: Dekker G.
Published: February 2008

Projected long‐range demands on the Nile water resources for irrigation, as found in the literature, are compared with estimates of the mean flow. Existing overyear storage capacity is taken into account. The possibilities for increasing the quantity of water that could be used are discussed. The cooperation between the Nile basin states in respect to their water resources is described.
Numerical simulation of flow in an aquifer overlain by a water table aquitard
Authors: Cooley Richard L.
Published: February 2008

An extension of the convolution integral produced by N. S. Boulton's ‘delayed yield’ theory describes vertical flow rate at the base of a unit such as an aquitard bounded at the top by a water table across which recharge is permitted and at the bottom by a variable drawdown boundary. The solution requires that the water table release water from storage instantaneously with a decline in head and that the compressibility of both the unit and the water in it be neglected. Application of the integral as an upper boundary condition for an aquifer underlying a water table aquitard allows approximation of the influence of the water table aquitard on the unsteady state head distribution in the aquifer. A simple, efficient procedure permits the use of a numerical approximation of the integral with a numerical groundwater flow model of the aquifer. An example solution demonstrates the high degree of accuracy of the method.
Some properties of link magnitude for channel networks and network patterns
Authors: Dacey Michael F.
Published: February 2008

The generating function is given for the magnitude of a link randomly selected from the collection of topologically distinct channel networks of magnitude n and from the collection of topologically distinct network patterns of magnitude n. For large n, the link magnitude from both sample spaces has the inverse Polya distribution. An urn model underlying this distribution provides an intuitive explanation for the very long tail of the probability distribution of the link magnitude.
Drawdown distribution around wells partially penetrating thick leaky artesian aquifers
Authors: Halepaska John C.
Published: February 2008

The differential equation governing nonsteady flow to a well in a thick leaky system has been solved by using transform techniques. Routines to tabulate the most general solution in type curve form have been developed and are available. The limiting curve of the tabulated function is the Hantush partial penetration type curve. With knowledge of the geologic framework the technique can be applied to certain field problems.
Budgetary constraints and benefit‐cost criteria
Authors: Viscusi W. Kip
Published: February 2008

Conventional benefit‐cost guidelines are erroneous, owing to their failure to recognize the realities of policy making. From appropriate consideration of budgetary constraints, the interdependence of projects, and the influence of project selection on future budgets the conclusion is that project selection should not follow crude rules of thumb, such as the order of project benefit‐cost ratios. By means of a dynamic Lagrangian multiplier model the maximum economic advantage principle for the political context is derived. This principle implies that an optimal project schedule does not require that all marginal benefit‐cost ratios be equal. For example, if a project increases the economic desirability of other projects, its own economic value increases. Moreover, a project increasing future budgetary allocations takes on increased economic desirability, since one of the project benefits equals the sum of the increased budgetary allotments, as weighted by the appropriate budgetary shadow premiums.
Cost‐benefit approach to hydrometric network planning
Authors: Wilson Kenneth C.
Published: February 2008

The costs of installing and operating hydrometric stations can be readily determined, but estimating the benefits, which arise from increases in the accuracy of design data for future projects, is more difficult. There is no single statistic that can represent the accuracy of the network output, and therefore a recent Canadian planning study decided to consider the information obtained from hydrometric networks under the three headings of mean discharge, flow dependability, and floods. The increase in accuracy from network intensification and the probable future benefits were then estimated separately for each of these three categories. Some of the techniques developed in this pilot study are outlined, and it is noted that, for the projections that were used and the conditions of the study area, increases in the accuracy of flow dependability and flood flow data outranked the mean flow category in regard to potential future benefits.
DO Prediction Model for a long river
Authors: Falkner Charles H.
Published: February 2008

A model for predicting the deoxygenation‐reoxygenation process in a long reach of a river is presented. The model is based on the concept of obtaining an instantaneous picture of the DO profile. The variational effects of flow, temperature, and river parameters are approximated by step functions that divide the river into subreaches. The approach is essentially a steady state approximation of a dynamic system. The problems and results of applying the model to a 180‐mile reach of the Wisconsin River are presented. Finally, the assumptions underlying the model construction are discussed.
Opportunity costs of a transbasin diversion: 2. The Columbia River Basin
Authors: Moncur James E. T.
Published: February 2008

When water supplies of a river basin are drawn on for importation into other regions, the value of services provided by the river to the economy of the exporting region will diminish. To evaluate the opportunity costs implied by, such a transbasin diversion, a previous paper developed a linear and dynamic programing model. Now the model is applied to the Columbia and Snake rivers in and near Washington state. Energy, irrigation, and water quality are directly accounted for in the model; some other water products enter only arbitrarily, if at all. Several solutions illustrate that both the time pattern and the location of the diversion are significant factors in determining the magnitude of the opportunity costs incurred by the exporting region.
An estimate of the role of lake effect snowstorms in the hydrology of the Lake Erie Basin
Authors: Webb M. S. , Phillips D. W.
Published: February 2008

The role of lake effect snowstorms in the hydrology of the Lake Erie basin is estimated by using climatological data. By comparing monthly snowfall over areas affected by lake effect storms off Lake Erie and Lake Huron/Georgian Bay with a nearby nonaffected area, it was possible to isolate the contribution from frontal storm systems (including their augmentation due to orography) and from lake effect storm activity. These latter storms were found to contribute only 6% of the mean seasonal snowfall over the entire basin. For the snow belt southeast of Lake Erie, lake effect snowstorms provided less than 20% of the total seasonal snowfall. This percentage is low in comparison with other Great Lake snow belts because of the diminished storm activity resulting from the freezing over of Lake Erie by midwinter. The water equivalent of all snowfall over the Lake Erie basin is equivalent to a 1.07‐foot depth over the Lake Erie area. Only 0.06 foot of this depth results from lake effect snowstorm activity.
Approximation of heat exchange at the air‐water interface
Authors: Yotsukura Nobuhiro , Jackman Alan P. , Faust Charles R.
Published: February 2008

The basic exchange equations for air‐water interface are approximated by the Taylor series expansion around an undefined base temperature in order to calculate short‐term heat exchanges. The expression ‘short‐term’ is used here to indicate averaging over a period on the order of 1 hour. Numerical tests based on data from two shallow streams verify that the base temperature should be chosen so as to minimize deviations between the base temperature and the actual water temperature. The daily average natural temperature observed at a reference point is the most practicable base. The daily equilibrium temperature calculated from meteorologic data may be used as a base as long as it does not deviate excessively from actual water temperatures. Whereas the short‐term natural temperature is the most accurate base, the short‐term equilibrium temperature has no merit as a base temperature of linearization.
Field calibration and evaluation of a nuclear sediment gage
Authors: Welch Norman H. , Allen Paul B.
Published: February 2008

Nuclear sediment gage readings were compared to stream cross‐sectional sediment concentrations for several storm events over a 3‐year period. Calibration curves, developed by least‐squares analysis, are presented for individual and combined storm events. Correlation coefficients for individual or combined storm events ranged from −0.86 to −0.99, and all were significant at the 1% level. Standard errors of estimate ranged from ±172 to ±1884 ppm. Sediment concentrations predicted with the calibration curves developed in this study were accurate enough for most applications. Although the particular nuclear gage used in this study is probably unsatisfactory for general use, the principle of monitoring sediment concentrations by nuclear techniques appears sound and feasible.
Introduction of time variance to linear conceptual catchment models
Authors: Mandeville A. N. , O'Donnell T.
Published: February 2008

Most linear conceptual models relating rainfall and runoff are time invariant and are based on two simple components, the linear channel and the linear reservoir. Time variant versions of these two components are defined, and expressions are obtained for their impulse responses. The convolution integral is used both to study different combinations of the two basic time variant components and to obtain the response of any time variant linear system to a given input. The theoretical background of more advanced models is discussed and it is suggested that time variance may be introduced into any linear model founded on these two conceptual components.
Determination of optimal kernels for second‐order stationary surface runoff systems
Authors: Diskin M. H. , Boneh A.
Published: February 2008

Adopting a discretization scheme for input, output, and kernel functions of second‐order Volterra series representation of the surface runoff system leads to a set of linear equations for the unknown ordinates of the two‐kernel functions. The equations are solved by an iterative descent optimization procedure taking into account also additional constraining equations derived from the properties of the kernel functions and the definition of the system adopted. The objective function for the optimization procedure is the sum of squared deviations between observed and predicted output ordinates for all storms included in the record. The inclusion of the constraining equations is done by an iterative scheme based on the penalty function method. The algorithm adopted for the solution converges to the optimal solution in a finite number of iterations, and its rate of convergence is independent of initial values adopted for the unknowns. A numerical example based on an eight‐storm record is included.
Interface refraction at the boundary between two porous media
Authors: Mualem Yechezkel
Published: February 2008

In steady flow, refraction of the interface between fluids takes place at the boundary between porous layers of different hydraulic conductivities. An analytical and graphical solution of this problem is presented. The steady interface, which is a streamline, is refracted in such a way that the ratio between the tangents of the angles that the interface makes with the normal to the surface separating the two layers equals the ratio between the corresponding hydraulic conductivities. However, in addition to the above condition of refraction of a streamline, in the present case the angles of refraction of the interface can take only definite values depending on the slope of the boundary between the layers and the ratio of their permeabilities. Laboratory experiments, carried out on a Hele‐Shaw analog, verified the analytical solution.
Steady seepage flow to sink pairs symmetrically situated above and below a horizontal diffusing interface: 1. Parallel line sinks
Authors: Wolanski E. J. , Wooding R. A.
Published: February 2008

As an aid in understanding the flow regime close to a pair of wells situated on opposite sides of a diffusing interface between freshwater overlying saline water, an idealized symmetrical system is considered. The interface is assumed to be horizontal, and gravitational effects are neglected. A uniform flow is assumed to be parallel to the interface, and it is postulated that the fresh and saline fluids are separated by a thin impermeable layer at a finite distance upstream from the sinks. The edge of the impermeable layer provides a definite starting point for diffusive mixing at the interface. As part of a large‐scale gravity system, flow in the upper fluid should bear a qualitative resemblance to field situations where freshwater is moving slowly over saltwater almost at rest. Boundary layer theory is used to treat the growth of the diffusive mixing layer, modified by the presence of the sinks, and the flux of salt to the upper sink is calculated as a function of the spacing and strength of the uniform flow. A periodic system of sink pairs without an applied flow is also considered. Exact solutions of the boundary layer equations are readily obtained for the two‐dimensional case. An approximate treatment of the system comprising a pair of point sinks in a uniform flow is deferred until part 2.
Effect of including water price on the conjunctive operation of a surface water and groundwater system
Authors: Mobasheri Fereidoun , Grant Sharon
Published: February 2008

A mathematical model is developed to study the impact of water price on residential water demand and on the conjunctive operation policy of a surface water and groundwater system. The economic objective is the maximization of the present worth of net benefits from operation of the supply system. The objective function and constraints are nonlinear. A nonlinear programing algorithm is used to find the optimum operation strategy for the conjunctive management of the supply sources. A hypothetical system is studied to test the efficiency of the computer program.
Multisite daily flow generator
Authors: Pentland R. L. , Cuthbert D. R.
Published: February 2008

In studies of upstream storage for flood control, recorded streamflow sequences are often of insufficient duration for acceptable reservoir design. This is particularly true if reservoir sites on several tributaries are being investigated, because the main stream peak flow may be the product of any one of an infinite array of potential hydrograph shapes on the tributaries. A daily flow generation model to synthesize correlated flood hydrographs on the main stem and tributaries of a large river system has been developed and tested in this investigation.
Peak load pricing model of an electric utility using pumped storage
Authors: Jackson Raymond
Published: February 2008

Electric utilities are increasing their use of water power at a rapid pace to supplement system capacity during peak demand intervals. During off‐peak periods electricity derived from fuel generators is used to store water, and when the peak period arrives, the demand is satisfied by production from both fuel and hydroelectric generators. This pumped storage technique is particularly well suited to nuclear plants that cannot be ‘turned off’ during low demand intervals. By using electricity for pumped storage, the nuclear generators can operate continuously at their most efficient output levels. This paper presents a peak load pricing model, based on partial equilibrium welfare criteria, for determining the optimal prices in the peak and off‐peak periods and the amount of electric power that should be used during the off‐peak intervals to pump water. Current peak load models have always assumed that the consumption and the production of electricity are instantaneous and have not considered the storage possibility by using water resources. A pricing rule for welfare maximization emphasizing capacity charges is first derived, and then a graphical model is developed that can be adapted to the installation of a particular utility. A method of evaluating plant expansion programs by using the model is also indicated, the benefits from increased consumption and lower operating costs being compared to the additional capacity cost. The suggested procedure can handle expansion programs of a complex nature including those faced with indivisibility constraints.
Network density of temperature profile stations and its influence on the accuracy of lake evaporation calculations
Authors: Crow Franklin R. , Hottman Steven D.
Published: February 2008

The accuracy of lake evaporation determined by the energy budget method depends on the precision of measurement of the total thermal energy content of the lake, which in turn is related to the number and distribution of the temperature‐measuring points. The number of sampling points to be used should be such that the error in the stored thermal energy is of the same magnitude as the error in the other terms in the energy budget. This problem was studied at Lake Hefner, a 2600‐acre off‐stream reservoir at Oklahoma City, Oklahoma. Ten evaporation periods of 1‐week duration each were included. Stored thermal energy was calculated on the basis of temperature profiles taken at 5‐foot depth increments at 19 locations uniformly spaced over the lake. Evaporation was determined by the energy budget method using stored thermal energy calculated on the basis of 1, 5, 11, or 19 temperature profile stations. Analysis showed the optimum number of stations to be 5, or one station per 520 acres. Using only one station resulted in an evaporation error of 8.2% at the deepest point of the lake. Increasing the number of stations from 5 to 19 resulted in an increase of accuracy of evaporation measurement of only 1%.
Viscous finger wavelength degeneration in Hele‐Shaw Models
Authors: Gupta Surendra P. , Varnon James E. , Greenkorn Robert A.
Published: February 2008

The displacement of one fluid by another (miscible or immiscible) in porous media is an important phenomenon that occurs in groundwater movement arid oil reservoir engineering. Practical examples are water flooding, solvent flooding, saltwater intrusion into coastal aquifers, and coning. Experiments are presented on viscous fingering in Hele‐Shaw models. The use of Hele‐Shaw cells facilitates fundamental studies of the viscous effects. For an immiscible displacement the dispersive and the relative permeability phenomena are absent. This investigation covers the entire scope of finger development from the incipient fingers predicted by Chuoke's theory to a parallel‐sided single finger. Results of several experiments run in a Hele‐Shaw cell with and without local heterogeneities show the wavelength degeneration to one finger for different flow conditions and the initial number of fingers. It was also found that the rate of growth develops almost immediately, well before the fingers are parallel sided. The mechanisms of wavelength generation and degeneration are discussed.
Time series analysis of the hydrologic regimen of a groundwater discharge area
Authors: Jackson R. E. , Gilliland J. A. , Adamowski K.
Published: February 2008

Methods of time series analysis were employed to examine climatological and hydrogeological variables associated with a groundwater discharge area in Manitoba, Canada. The hydrogeological variables, daily groundwater evapotranspiration and inflow rate, were adequately modeled by a first‐order Markov process. Nonrandom fluctuations associated with the weather and circulation of the North American summer climate were identified in the time series of mean daily temperature and groundwater evapotranspiration; daily precipitation was random. Statistical filtering of the hydrogeological time series showed that two processes were associated with seasonal maximums in the groundwater evapotranspiration series, one being due to the propagation of groundwater recharge through the flow system and the other being due to climatic effects on the discharge area, in particular, the Lisse effect. Finally, it is explained why the water table fluctuates within a small range of depth in groundwater discharge areas.
Effect of insoluble grains on leachate from porous beds
Authors: Li Wen‐Hsiung , Feng Francis H. S.
Published: February 2008

In the leaching of a porous bed composed of soluble and insoluble grains the concentration of dissolved material in the leachate is influenced by the presence of the insoluble material. This influence is studied by modeling the bed as a laminar tube with a wall composed of consecutive soluble and insoluble rings. It is found that for cases with
an equivalent boundary condition may be used. The presence of the insoluble wall surfaces has a negligible effect on the leachate if they are less than 50% of the total wall surface.
Unsteady temperature prediction for cooling ponds
Authors: Yeh Gour‐Tsyh , Verma A. P. , Lai Fu‐Hsiung
Published: February 2008

The mixed Lagrangian and Eulerian approach is proposed to study the thermal and hydraulic performance of cooling ponds that are used mainly to dissipate the waste heat from power plants into the atmosphere. The hydraulic behavior of the cooling pond is analyzed by the Eulerian method, and the Lagrangian approach is used to study the thermal distribution, ‘Isotime’ lines are obtained by numerically solving the governing hydrodynamic equations. The Lagrangian temperature is obtained by solving the energy equation either numerically with the fourth‐order Runge‐Kutta method or analytically with the linearization of the net heat flux at the water surface. The Lagrangian temperature is then converted to the Eulerian temperature through the isotime lines. This model is applied to predict flow patterns, isothermal lines, and discharge temperature for a cooling pond in the southwestern United States.
Evaporation retardation by monolayers
Authors: Greif R.
Published: February 2008

The reduction in the rate of evaporation of water by hexadecanol monolayers is analyzed by considering two conductances. A value of 0.95 cm/sec is reported for the vaporization step conductance.
Power Law Dependence on Time of River Flood Decay and Its Relationship to Long‐Term Discharge Frequency Distribution
Authors: Schubert G. , Lingenfelter R. E.
Published: February 2008

River discharge frequency distributions, based on long‐term records of daily streamflow, are often found to have an inverse power law dependence on discharge. This is shown to reflect the recession of individual river floods, which are found to have an inverse power law dependence on time with an exponent of 1/(s + 1) where s is the slope of the power law dependence on discharge of the river discharge frequency distribution. This relationship will allow forecasting of river discharges with about ±5% uncertainty for as much as 30 days after flood peaks.
Induced safety algorithm for hydrologic design under uncertainty
Authors: Bogárdi István , Szidarovszky Ferenc
Published: February 2008

The induced safety algorithm (ISA) is a method for calculating the margin of safety in the design of hydrologic structures under the uncertainty due to finite sample size. The ISA may be applied to the design of a new structure or the redesign of an existing one; the initial design criterion may be calculated by benefit‐cost or be prescribed by regulation. The optimum decision is reached by maximizing the sum of three terms (in case of redesign to a larger value): the discounted economic benefit due to uncertainty reduction, the average loss averted, and the incremental construction cost. The uncertainty on the distribution function of the state variable (yearly peak flow) is encoded by the probability density function of flow pertaining to a fixed return period. Simulation is used to calculate the distribution of the state variable. Two examples of levee design in Hungary illustrate the method.