bluuebunny/crossref_metadata_2025 huggingface dataset:
Response of a finite‐diameter well to an instantaneous charge of water
Authors: Cooper Hilton H. , Bredehoeft John D. , Papadopulos Istavros S.
Published: February 2008

A solution is presented for the change in water level in a well of finite diameter after a known volume of water is suddenly injected or withdrawn. A set of type curves computed from this solution permits a determination of the transmissibility of the aquifer.
Economic analysis of alternative flood control measures
Authors: James L. Douglas
Published: February 2008

A digital computer program was developed for determining the optimum combination of structural and nonstructural measures for flood control according to the criterion of economic efficiency. The program may be readily applied by any agency interested in analyzing the relative merits of structural and nonstructural measures or in more rapid economic analysis of alternative channel improvement designs. It selects the optimum combination of channel improvement, flood proofing, and land use control for each portion of the flood plain during planning stages of specified duration. The program was used to relate the optimum combination of the three measures to specific flood‐plain properties. Finally, the sensitivity of the nature and the total cost of the optimum program was related for various flood‐plain conditions to variation in cost of channel improvement, cost of land use control, cost of flood proofing, right‐of‐way value, value of the coefficient relating flood damage to flood severity, value of open space preserved in an urban area, extent of aversion to irregular timing of flood damage, discount rate, population projections, and the exclusion of alternative combinations. (Key words: Flood control; flood plains; flood proofing; land use control)
Erodibility indices for wildland soils of Oahu, Hawaii, as related to soil forming factors
Authors: Yamamoto Teruo , Anderson Henry W.
Published: February 2008

Soil samples collected along 31 transects in the watersheds of the Koolau and Waianae ranges were analyzed in the laboratory for the size distribution of water‐stable aggregates and suspension per cent. Indices of soil erodibility were related by principal component analyses with varimax rotation to these 7 soil‐forming factors: parent material, rainfall, elevation, vegetation type, slope, aspects, and zone. Parent rock material was the most important factor in explaining variation of water‐stable aggregates of soils in Hawaii. Nevertheless, differences in water‐stable aggregates were also associated with differences in vegetation type and other soil‐forming factors. Most of the soils studied were rated as slightly to moderately erodible under full vegetative cover. The loose condition plus the dispersive and slaking characteristics of volcanic ash soils suggest that they may be twice as erodible as soils of basaltic flow or of the colluvial origin. Among the soil characteristics that serve as indices of erodibility, the suspension per cent was found to be independent of other measures; hence, it may be expected to serve well as a part of an erodibility ratio, such as suspension‐mean weight diameter or a surface‐aggregation ratio. Conversion of the native koa‐ohia scrubby forests by planting paperbark or silk‐oak trees promises to result in development of less erodible soils as well as more useful forest products.
Estimating incident terrestrial radiation under all atmospheric conditions
Authors: Anderson E. A. , Baker D. R.
Published: February 2008

To apply a complete energy balance to the computation of evaporation or snowmelt, radiation data are necessary. At present there is a reasonably adequate network of incident solar radiation stations. However, a network of all‐wave radiometers does not exist. It is therefore evident that to apply the energy budget technique to hydrological problems, incident long‐wave radiation has to be estimated. An empirical equation is developed by which incident long‐wave radiation can be computed from observations of surface air temperature, vapor pressure, and incident solar radiation. Based on comparisons of estimated and observed incident long‐wave radiation at six locations, the following conclusions seem warranted: (1) The equation should give results comparable within a few percent on a long‐term basis (six months or longer); (2) For any specific atmospheric condition, there seems to be no tendency for the equation to over or under compute or to give increased scatter; (3) When data for periods of six‐months or more were analyzed, correlation coefficients of approximately 0.90 were obtained between computed and observed daily radiation values.
A sensor for water flux in soil. “Point source” instrument
Authors: Byrne G. F. , Drummond J. E. , Rose C. W.
Published: February 2008

The theoretical analysis and laboratory calibration of a sensor to measure fluid flux in soil or other porous medium shows that a flow velocity of 10−4 cm sec−1 can be readily measured, and that sensor output is uniquely related to flux. The flow to be measured causes asymmetry in the temperature field,generated by an approximation to a point source of heat located centrally in the instrument. The temperature difference due to this asymmetry gives rise to the output of the instrument.
Schemes for handling inconsistent matrices
Authors: Fiering Myron B
Published: February 2008

The increasing role of multivariate statistical techniques, a trend based on the growing availability of computers and on pressures for streamlined representation of multi‐dimensional arrays of data, carries with it the responsibility for using efficient techniques to manipulate matrices and arrays. It frequently happens that all records in a multivariate system (of flow records, quality measurements, or whatever) are not equally long, and that some subsets of these records do not present a consistent pattern of correlation when the entire bivariate correlation matrix is reconstructed. If one or more estimate is such that the entire correlation matrix is rendered inconsistent, repairs must be effected before continuing the multivariate analysis. Two algorithms for systematically finding a set of adjustments that satisfy the requirements of consistency are given. Of course, the results are not unique.
Similitude theory applied to correlation of flume sediment transport data
Authors: Barr David I. H. , Herbertson John G.
Published: February 2008

A second variant of the method of synthesis, the method of linear proportionalities, is presented and shown to be a powerful device for seeking correlation procedures for sediment transportation data. It is apparent that correlations for sediment transportation data under conditions of quasiuniform flow are of the same basic form as those for rough pipe flow, with some amplification for practical reasons. Certain established correlations are shown to be based on similarity equations from which parametric terms have been omitted, mostly without justification. A rigorous method of correlation compatible with feasible laboratory procedures is presented and illustrated in figure form using available data. It was found that the bulk of the published data was in a form unsuitable for use in a rational correlation. The authors conclude that new experimentation is required and that this could best be done by co‐operation among institutions with the necessary apparatus.
Steps toward a better understanding of urban runoff processes
Authors: Brater E. F.
Published: February 2008

Rainfall and runoff from drainage basins in various stages of urbanization were analyzed to determine the initial retention, the hydrologically significant impermeable area, and the infiltration capacities of the permeable portions of the basins. The drainage basins, varying in size from 9.5 to 185 square miles, are located in the Detroit metropolitan area. Techniques were developed that largely eliminated personal judgment in separating surface runoff from ground water discharge. Infiltration capacities in this region are from 3 to 5 times higher in late summer than in early spring. The average initial retention for the basins studied is approximately 0.2 inch. The hydrologically significant impermeable area appears to be closely related to the population density, but the effect of other factors is being studied. An investigation of the cause of seasonal and short period variations of infiltration capacity may provide a better understanding of the infiltration process.
The effects of thermal pollution on river ice conditions
Authors: Dingman S. L. , Weeks W. F. , Yen Y. C.
Published: February 2008

An attempt is made to calculate the length of the ice‐free reach that develops during the winter below a thermal pollution site on a river. A differential equation for the steady‐state heat balance of a volume element of a river is developed, which leads to the expression

urn:x-wiley:00431397:media:wrcr305:wrcr305-math-0001

where x is distance downstream from the pollution site to the cross section where the water temperature equals Twx, Two is water temperature at x equals zero, Q* is rate of heat loss from the water surface, and Cx is a constant that includes flow velocity and depth. The value of x at Twx equals 0°C is taken as the length of the ice‐free reach. Q* is the sum of heat losses due to evaporation, convection, long‐ and short‐wave radiation, and other processes, each of which is evaluated by an empirical or theoretical expression. The two principal limitations in accurately calculating downstream temperature changes are related to difficulties in evaluating the degree of lateral mixing in natural rivers and the convective and evaporative heat losses under unstable atmospheric conditions. Observations of lengths of ice‐free reaches on the Mississippi River are in good agreement with the calculated values. Significant portions of the St, Lawrence Seaway can be kept ice‐free by the installation of nuclear reactors at appropriate locations.
Seepage from channels through layered porous mediums
Authors: Jeppson Roland W.
Published: February 2008

Solutions to steady‐state free surface problems of seepage from channels through porous mediums consisting of layers of different permeabilities are obtained by using the methods of finite differences. In the formulation of the problem, the magnitudes of the coordinates x and y are considered the dependent variables, and the potential function and the stream function are considered the independent variables. The method permits the shape of the interface that separates the two layers with different permeabilities to be specified. In the event that each layer is anisotropic, but with different ratios of horizontal to vertical permeabilities, the interface between the two layers is restricted to being horizontal. Example solutions are given for arbitrarily specified interfaces for both the case of seepage from a trapezoidal channel through homogeneous isotropic mediums in each layer (but of different permeabilities) and the case of anisotropic mediums in which the ratio of horizontal to vertical permeabilities is different for each layer.
Optimal Control of Linked Reservoirs
Authors: Schweig Z. , Cole J. A.
Published: February 2008

Control rules for linked reservoirs meeting a common demand are evaluated for a two storage case. Draw‐off can be made from either of the reservoirs directly to supply, and transfers are permitted from the smaller to the larger reservoirs. Dynamic programming is effective in selecting the optimal control rules, for any stage of reservoir contents, given a defined objective of operation. The objective is expressed in monetary terms, relating to transmission, purification, or shortage costs, which are to be minimized in the long term. The case considered allows monthly inflows to the reservoirs to be treated as random variates; first order serial correlation of inflows is expressed by using ‘high’ or ‘low’ inflow distributions, according to whether the previous month's inflow was above or below its mean. Present worth factors, switch‐on costs, and costs of shortage that vary nonlinearly with total deficit can all be brought into the reckoning.

The paper includes a numerical example of the dynamic programming calculation for a system of a finite surface reservoir and a full aquifer, the latter having limited pumpage. Also, the flow diagram for a computer program is given, which incorporates inflow, draw‐off, storage volumes, and operating costs as general parameters. Using this program, the convergence to optimal control rules has been obtained, for the most part within 5 years of iteration. Given the optimal control rules for an assumed reservoir system, it becomes possible to form transition matrices of contents, by an adaptation of Gould's method. The steady‐state solutions of the matrices show probabilities of each reservoir's contents in the long term. These lead to a long‐term operating cost for consideration at the design stage of the system.
Some Thermodynamic Relationships for Soils at or Below the Freezing Point: 2. Effects of Temperature and Pressure on Unfrozen Soil Water
Authors: Low Philip F. , Hoekstra Pieter , Anderson Duwayne M.
Published: February 2008

Thermodynamic methods are presented for calculating, from the water adsorption isotherms, the change in unfrozen water content of a partially frozen soil with temperature at a constant pressure or with pressure at a constant temperature. Then, using pertinent experimental data for Na‐Wyoming bentonite, the increase in unfrozen water caused by a confining pressure of 100 atm is obtained as a function of temperature. Such information is shown to be relevant to the mechanical properties of frozen soils under stress.
Boundary Flow in Laboratory Permeameters Used To Stimulate Recharge by Cyclic Water Spreading
Authors: Worcester B. K. , Mcintosh T. H. , Wilson L. G.
Published: February 2008

The contribution of boundary flow to the hydraulic conductivity values obtained from laboratory permeameters employed in cyclic flood‐dry infiltration studies was evaluated. Hydraulic conductivity in the boundary zone was less than that of the inner matrix for a 2‐mm sand. Conversely, the flow rate was greatest in the boundary zone for the finer textured sandy loam soils. The divergence between the hydraulic conductivity of the inner zone and the boundary zone was greatest during the first flooding period. For both matrix zones, the changes in hydraulic conductivity within a flood cycle and with a number of flood cycles, although of different magnitude, tended to be similar and parallel. A laboratory permeameter design is presented to facilitate partitioning the relative contributions of flow in the boundary and inner zones on the hydraulic conductivity values of soils.
A Sensor for Water Flux in Soil: 2. ‘Line Source’ Instrument
Authors: Byrne G. F. , Drummond J. E. , Rose C. W.
Published: February 2008

Two sensors are described that measure the flux of water in soil, or the flux of other fluids in any porous medium. The electrical output of such instruments can be of sufficient magnitude that a water flow velocity of 10−4 cm/sec in soil is readily measured. The flow to be measured causes asymmetry in the temperature field generated by a line source of heat located centrally in the instrument. The temperature difference due to this asymmetry gives rise to the output of the instrument. A theoretical analysis of the temperature field is given for boundary conditions appropriate to each type of sensor. Theoretical and experimental calibrations agreed closely when assumptions in the theory were realized experimentally. The analysis was used to elucidate design principles and their effect on instrument performance.
Letters: Piezometer for Monitoring Rapidly Changing Pore Pressures in Saturated Clays
Authors: Wolff Roger G. , Olsen Harold W.
Published: February 2008

A modified Imperial College Piezometer incorporating a differential pressure transducer is a highly sensitive pore pressure measuring device unaffected by the total pressure of the environment in which it is placed. It is sufficiently rugged for field installation and provides the option of field calibration in situ.
The Use of a Square Grid System for Computer Estimation of Precipitation, Temperature, and Runoff
Authors: Solomon S. I. , Denouvilliez J. P. , Chart E. J. , Woolley J. A. , Cadou C.
Published: February 2008

Studies on water resources in the last few years have had the tendency to encompass larger and larger areas. The increase in size and sophistication of these studies makes the use of computers almost mandatory. To adapt computers to this type of study, the study area must be converted to a schematic representation which is easily manageable by computers. A simple and reasonable way of doing this is to cover the study area with a square grid, which may then be considered as consisting of a matrix of squares. This system can be used to store, process, and retrieve information and may have numerous applications in the fields of hydrology, hydraulic power, economics, etc. The paper presents the application of the square grid system to the estimation of the precipitation, temperature, and runoff distribution in a large area and shows how the use of the system enables efficient combination of the meteorologic and hydrologic information available in assessing the precipitation, temperature, and runoff distribution. An example of such a computation for a 43,000‐square‐mile area is shown and the advantages of the method over the usual techniques emphasized.
The Initial Phase of the Rising Hydrograph of Turbulent Free Surface Flow with Unsteady Lateral Inflow
Authors: Brutsaert Wilfried
Published: February 2008

An exact solution is obtained for the de Saint Venant equations describing flow over a plane or in a very wide channel with a general turbulent friction law and with a uniform lateral inflow as a power function of time valid for the space‐time domain bounded by 0 ≤ x ≤ L, t = 0, by the forward characteristic originating at x = 0, t = 0, and by the backward characteristic originating at x = L, t = 0. The quantity L denotes the length of the flow region, x the direction of flow, and t the time. We found that, for very small values of time, the uniform flow velocity is everywhere directly proportional to t regardless of the nature of the lateral inflow. For a very large slope or a large roughness of the plane, or for a very small constant lateral inflow, the present solution reduces to the result obtainable with the kinematic wave approximation. (Key words: Hydraulics; overland flows; runoff)
Fluid Flow in the Western Canada Sedimentary Basin: 1. Effect of Topography
Authors: Hitchon Brian
Published: February 2008

The main variables affecting the fluid potential distribution are topography and geology, and the effect of topography is treated by consideration of the three‐dimensional flow net by means of fluid potential slice maps and cross‐sections and is shown to be adequate to explain the major flow net. The dominant fluid potential in any part of the basin corresponds closely to the fluid potential at the topographic surface in that part of the basin. Major recharge areas correspond to major upland areas, and major lowland regions are major discharge regions. Large river valleys commonly exert a drawdown effect on the fluid potential distribution, which may be observed to depths of up to 5000 feet. The presence of a thick sequence of highly permeable Upper Devonian and Carboniferous carbonate rocks in the medium‐depth portion of the Alberta basin has resulted in the development of a low fluid potential drain, which essentially channels flow from most of the Alberta basin towards the Athabasca oil sands and has modified the theoretical relation between local and regional flow systems.
Computer Experiments with Fractional Gaussian Noises: Part 3, Mathematical Appendix
Authors: Mandelbrot Benoit B. , Wallis James R.
Published: February 2008

The present ‘Appendix’ is devoted to mathematical considerations designed to fill in the innumerable logical gaps left in the preceding paper. Even though most proofs will be merely sketched or omitted, the notation remains heavy, and some readers may wish to skip to formulas 1 and 2, which define ‘Type 1 functions.’

Most of what follows is closely patterned after Mandelbrot and Van Ness [1968], which contains additional mathematical details and references to the few earlier articles, where fractional Gaussian noises were fleetingly considered as purely mathematical entities.
Prediction of Sediment Profiles in Open Channel Flow by Turbulent Diffusion Theory
Authors: Barfield Billy J. , Smerdon Ernest T. , Hiler Edward A.
Published: February 2008

Using turbulent diffusion theory, a non‐steady‐state model of sediment transportation is developed in the form of a partial differential equation relating the change of sediment concentration with time to the change of concentration in space. The required input to the model is the root‐mean‐square fluid velocity, the time scale of turbulence, and the mean particle fall velocity. Preliminary experimental investigations are reported using turbulence measurements made over a smooth channel. When smooth channel turbulent intensities were used, predicted sediment concentrations were low when compared with actual measurements. When turbulent intensities were used from an artificially roughened channel, the predicted concentrations were; of the same order as the measured concentrations. Since data were not available for turbulent intensities in alluvial channels, no conclusion could be made about the validity of the model.
Source Areas of Storm Runoff
Authors: Betson Roger P. , Marius John B.
Published: February 2008

An investigation of runoff from a 4.64‐acre agricultural watershed included the use of subplots, observation wells, and piezometers to determine the extent of source areas of storm runoff within the catchment. Studies of data collected showed that most of the storm runoff usually originates from a small portion of the total drainage area and that the location and extent of the source area is dependent upon rainfall intensity, antecedent moisture, and the depth of the A horizon soil.
Two‐Dimensional Seepage of Ponded Water to Full Ditch Drains
Authors: Warrick A. W. , Kirkham Don
Published: February 2008

Seepage of ponded water to equally spaced ditch drains running full is analyzed mathematically with four separate cases considered. In the first case, an impermeable soil barrier is present at a finite depth, and the ditches are a finite distance apart; in the second case, no impermeable soil barrier is present, and the ditches are a finite distance apart; in the third case, an impermeable barrier is present, but the ditches are considered an infinite distance apart; and in the fourth case, no impermeable barrier is present, and the ditches are considered an infinite distance apart. The ditches may penetrate part or all of the way to an impermeable barrier. Schwartz‐Christoffel transformations are used to solve the first case by mathematically transforming both the physical z‐plane and the complex potential w‐plane to a common auxiliary t‐plane, resulting in relationships of w and z to t and, consequently, of z to w. Solutions for the other three cases are found by taking limiting values of the first case. Two flow nets are presented to illustrate the results. For the parameters chosen, the flow rate without an impermeable barrier present is 10% greater than when an impermeable barrier exists at a depth of 0.2 times the ditch semispacing. The flow nets illustrate the rapid decrease in surface water intake at increasing distances from the ditch. A nomogram gives seepage rates when no impermeable barrier is present and infinitely wide spacing is used. An illustration shows that the nomograph is useful to estimate seepage rates for flow media of finite depth and width.
Comparison Between Rain Gage and Lysimeter Measurements
Authors: Morgan D. L. , Lourence F. J.
Published: February 2008

Rain gage data were compared with ground level precipitation as determined with a highly sensitive weighing lysimeter 20 feet in diameter. Rain gages of various types were tested in the Central Valley of California during twenty‐four storms in the 1966–1968 rainfall seasons. Rainfall totals for each storm as measured by the lysimeter and by several rain gages in its vicinity were compared by regression analysis. Wind effects on a standing gage seemed unimportant, since agreement was close between a standard 8‐inch rain gage mounted in the normal standing position and a USSR 3000‐square‐centimeter rain gage mounted at ground level. Storm totals from these two gages spaced about ten feet apart averaged 4% higher than catches measured 450 feet away by the lysimeter and a Fischer and Porter digitizing rain gage spaced about 10 feet apart. Fischer and Porter gage storm catch values varied generally about the mean value of the lysimeter data. The coinciding means of all of the data from these two instruments suggest that wind effects compensate over the period of storms studied.
Steady flow of water through a two‐layer soil
Authors: Srinilta Sam‐Arng , Nielsen D. R. , Kirkham Don
Published: February 2008

A laboratory study of water moving steadily through an isothermal two‐layer soil is analyzed by using Darcy's equation for unsaturated flow. Factors considered were thicknesses and kinds of topsoil and subsoil, depth of surface water ponding, magnitude of outflow water pressure, and soil water history of the profile. Soil water pressure distributions were measured at 5‐cm depth intervals along the vertical columns. The unsaturated hydraulic conductivity was measured for sorption and desorption for each of four soils used as topsoil and subsoil in the two‐layer columns. Values of hydraulic conductivity as a function of soil water pressure were used to predict the measured soil water pressure distributions and steady state fluxes. The agreement between predicted and measured profiles is exceptionally close. The necessity of distinguishing between sorption and desorption, of obtaining a uniform soil bulk density distribution within each soil layer, and of ascertaining the hydraulic conductivity as a function of soil water pressure is discussed in relation to the predicted soil water pressure distribution and flux values.
Use of membrane filters in gravimetric analyses of particulate matter in natural waters
Authors: Eaton John S. , Likens Gene E. , Bormann F. H.
Published: February 2008

The weights of membrane filters used in gravimetric analysis of water were significantly changed by electrostatic charge, leachable material within the filters, and absorption of atmospheric moisture. Millipore type HA filters lost an average of 0.31 ± 0.07 mg or 0.32% of their dry weight as leachable material when 6 liters of distilled water were filtered. About 165 ml were required to remove 50% of the total leachable material removed by 1000 ml. These filters absorbed moisture from the atmosphere very rapidly during the first minute of exposure and at a much slower rate thereafter. The leachable material contributed to moisture absorption. Desirable drying temperature and time for Millipore type HA filters was determined. Other filters were compared; recommendations for the use of these filters are given.
Use of the Critical Period in Reservoir Analysis
Authors: Hall W. A. , Askew A. J. , Yeh W. W‐G.
Published: February 2008

The purpose of this study is to define ‘critical period’ in conjunction with reservoir design and operation and then to analyze the usefulness of the concept in the evaluation of deficiencies of water for project planning purposes. Streamflow records from a number of rivers in the United States are analyzed, and certain defined characteristics of their various critical periods are derived. These characteristics are shown to be functions of both the active storage and the degree of variation in annual streamflow. The dates of occurrence of the critical periods from historical records tend to be stable within certain geographic areas and over a range of active storages. A study is made of the significance of the critical periods and their associated droughts respecting their use for design purposes. This is done by generating large numbers of equally likely hydrographs of the same length as the historical record and comparing the critical periods and yields of these synthetic records with those found in the historical record. Some of the synthetic records produced critical periods in which the severity, measured by the decrease in the full record firm yield, was greater than the historical. However, the generated records as a whole had significantly less severity than the historical records of the same length. The critical periods also showed a strong tendency for nesting, i.e., the larger critical period includes within its duration the smaller critical periods over a wide range of storage and target draft. These observations suggest, but do not prove, that the more severe critical periods observed in historical records may be due to major perturbations of the cause‐effect relationships not reflected by the hypothesis of static probability relationship (i.e., constant parameters).
Potential Evaporation as a Manifestation of Regional Evaporation
Authors: Morton F. I.
Published: February 2008

The temperature and humidity of the lower atmosphere are treated as causes of evaporation from a small continuously moist area and as effects of evaporation from a large area with variable moisture supply. This leads to the formulation of a model in which the sum of the regional and potential evaporation is equal to the evaporation equivalent of the absorbed insolation. Such a formulation permits the regional evaporation, a product of climatic, soil moisture, and vegetation processes, to be estimated by its effects on climatologic or evaporimeter observations. Test data are derived from class A evaporation pan observations from the near‐arid regions of the southwestern United States, and the near‐humid regions of Ireland and from records of rainfall and runoff for Irish river catchments. Comparisons with the model predictions provide good evidence for the validity of the model and interesting insights into its hydrologic and climatologic implications.
Nonlinear programing applied to regional water resource planning
Authors: Young George K. , Pisano Mark A.
Published: February 2008

Methods of nonlinear programing enable us to find the least‐cost mix of alternatives (reservoirs, weather modification, wells, desalination, and treated waste water) to satisfy future water demands within a region. The analysis demonstrates that analytical techniques can be applied to the complex problem of water supply to make the planning process more meaningful. Decisions can be made with some degree of confidence that they will not be outdated before initiated. A sensitivity analysis is attempted in an effort to define the effect of future technology on the alternative sources of water, but because of the unpredictability of this factor, other approaches must be tried.
Soil temperature profiles during infiltration and redistribution of cool and warm irrigation water
Authors: Wierenga P. J. , Hagan R. M. , Nielsen D. R.
Published: February 2008

Soil temperatures were measured in field profiles irrigated with cool and warm water and also measured in nonirrigated soil. Differences in soil temperature between plots after irrigation with cool (4.1°C) and warm (21.6°C) water, persisted longer at the lower soil depths. The time required after an irrigation for these differences to decline to less than 1°C was 14 hours at the 1‐cm depth, 36 hours at the 10‐cm depth, and 42 hours at the 20‐cm depth. A numerical procedure developed for predicting changes in soil temperature through the soil profile after irrigation with cool and warm water gave good agreement between observed and calculated values in the subsoil but not in the surface soil. During infiltration heat transfer occurred mainly by mass movement, whereas after 10 hours soil heat transfer below 10 cm occurred mainly by conduction.
Evapotranspiration from bare, herbaceous, and aspen plots: A check on a former study
Authors: Johnston Robert S.
Published: February 2008

Soil moisture depletion was measured and evapotranspiration estimated on high elevation plots with three cover conditions: bare, herbaceous, and aspen‐herbaceous. Neutron moisture measurements were taken to a depth of 9 feet. The 4‐year average annual evapotranspiration losses were 11.28, 15.27, and 21.00 inches from the bare, herbaceous, and aspen‐herbaceous plots, respectively. Summer rainfall varied from 1.13 to 10.43 inches during this study. Soil moisture depletion to a depth of 6 feet and estimated evapotranspiration on these plots were reported by Croft and Monninger [1953]. The results of this present study substantiate the earlier report concerning the comparative water savings to be realized by vegetative manipulation. They show that removing deep rooted aspen can reduce the average evapotranspiration by about 6 inches per year from a 9‐foot profile.
Thermal conductivity of snow by a transient state probe method
Authors: Jaafar H. , Picot J. J. C.
Published: February 2008

A transient state thermal conductivity probe (¼″ in diameter, 30″ in length) is described along with the method by which it is used to measure thermal conductivity of snow. Heat is supplied electrically at a constant rate to the probe at a given time after insertion into the sample. After a four minute lag, a plot of probe temperature rise against logarithm of time since the start of heating, gives a straight line whose slope is inversely proportional to sample thermal conductivity and proportional to the heating rate. The probe was calibrated against a standardized oil, and the constant was found to be unity. Values for artificially packed snow in the laboratory agreed with published data. However, values found in the field were considerably lower. The device is recommended for field measurements since data can be obtained with minimum disturbance of the snow.
The Disposition of Snow Caught by Conifer Crowns
Authors: Satterlund Donald R. , Haupt Harold F.
Published: February 2008

Snow interception studies during the warm winters of 1966–1967 and 1967–1968 in northern Idaho revealed that Douglas fir and western white pine saplings caught about one third of the snow that fell in 22 storms. More than 80% of the snow initially caught in the crowns ultimately reached the ground being washed off by subsequent rain, falling by direct mass release, or dripping as melting snow. Only a small portion was lost by evaporation.
A Model of Water Quality Management Under Uncertainty
Authors: Upton Charles
Published: February 2008

Although the problems of water quality management are usually analyzed in the context of nonstochastic models, such an analysis may be misleading because of the substantial stochastic elements in streamflow. The effects of variance in streamflow are considered in this paper. The analysis shows that the problems of uncertainty may be dealt with by selecting a critical value of streamflow ƒθ and then by treating pollutants sufficiently so that if streamflow falls above (or below) that critical value the water quality standard will (or will not) be met. The greater the variance in streamflow, the lower the optimal critical value. Further, the level of treatment of pollutants is higher under uncertainty than it would be if there were no variance in streamflow.
Post‐Irrigation Movement of Soil Water: 1. Redistribution
Authors: Gardner W. R. , Hillel D. , Benyamini Y.
Published: February 2008

Water content measurements by γ‐ray attenuation in soil columns were made during redistribution following irrigation. Approximate solutions of the unsaturated flow equation are derived that describe the water content above the initial wetting front as a function of time. For times sufficiently large, these solutions reduce to the frequently used empirical expression W = a t−b, where W is soil water content, t is time, and a and b are constants. These constants can thus be related to the capillary conductivity and soil water diffusivity.
Optimal Planning of a Coastal Collector
Authors: Shechter M. , Schwarz J.
Published: February 2008

This investigation determines the optimal design of a collector using seaward groundwater flow in a coastal aquifer. The optimal design is obtained by analyzing the interrelated hydrologic, engineering, and economic aspects of the project. The optimal size of the project determines the pumping rate and the pumping policy, as well as the location of the wells in relation to the coast. The present work identifies a model of the relevant hydrologic relationships in the aquifer, formulates a criterion for economically efficient utilization of the aquifer, estimates the model parameters, and determines an optimal project size given specific numerical values of the parameters.
Linear Programing Models for Estimating the Agricultural Demand Function for Imported Water in the Pecos River Basin
Authors: Gisser Micha
Published: February 2008

This paper provides the results of applying parametric linear programing methods to estimate the agricultural demand function for imported water in the Pecos basin. A parametric linear programing model suitable for the Pecos basin is developed. Agricultural activities in which land is irrigated either by local or imported water and by either ditch or sprinkler irrigation are developed and adjusted for forecasted 1980 prices. These agricultural activities are used by the parametric linear programing model, and various agricultural demand functions are obtained for the Pecos basin. These functions show the expected quantities of imported irrigation water that would be demanded at different prices and under a variety of constraints.
Linear Decision Rule in Reservoir Management and Design: 2. Performance Optimization
Authors: Revelle Charles , Kirby William
Published: February 2008

The application of linear decision rules to reservoir management and design is extended in two directions. First, an improved linear decision rule is derived for reservoirs suffering evaporation losses. Release commitments generated by this rule are based on the storage at the beginning of the period, the predicted evaporation depth in the period, and the linearized storage area curve of the reservoir. A clearer and more rigorous derivation of the chance constraints, including the effects of both evaporation losses and possible failures to meet previous commitments, is presented. Second, several reservoir performance measures are formulated as objective functions that can be optimized by linear programing. These performance measures include expected and reliable values of storages and releases, deviations from targets, and reliabilities of achieving stated goals.
Deep Well Disposal of Waste Waters in Saline Aquifers of South Florida
Authors: García‐Bengochea José I. , Vernon Robert O.
Published: February 2008

Florida is underlain by very rich water‐bearing strata commonly referred to as the Floridan aquifer. Solution channels and caverns in carbonaceous rocks are found at different depth intervals in extensive, thick (several thousand feet) sections of limestones and dolomites. In south Florida the bottom part of the Floridan aquifer includes extremely cavernous strata commonly referred to as the ‘Boulder Zone’. Chloride concentration in the water of the Boulder Zone is over 2000 mg/1. Because of this, large volumes of brine from oil fields are reinjected into this zone. Since 1966 industrial waste (essentially 1% acetic acid) has been injected into a disposal well drilled to the top of the Boulder Zone southeast of Lake Okeechobee. Planning and monitoring of this well have included the cooperation of government and private interests. Experiences, results, and potential of this zone for further similar uses are discussed.
Selective Element Recovery from Oil Field Brines
Authors: Angino Ernest E.
Published: February 2008

With the attention now being focused on the two problems of water pollution and usage and natural resource utilization, the recovery of compounds dissolved in subsurface brines takes on greater importance with each passing year. More than 325 billion gallons of oil field brines (∼ 8 × 109 barrels) are brought to the surface yearly in the United States. Most of these brines are wasted and/or are returned to the subsurface without any attempt of stripping the contained salts. The volume of this brine is such as to warrant greater consideration of the economic feasibility of extracting much, if not all, of the dissolved components therein. In many instances the salts dissolved in oil field brines could be extracted profitably, if modern extraction techniques were used or refined. Simple extraction processes for soda ash, sodium carbonate, caustic soda, magnesium and calcium sulfate, trace elements and others are available. For example, sulfur can be recovered by using a barium resin to precipitate the sulfate as BaSO4, which can then be made to yield sulfur by a short four step conversion process. Magnesium can be precipitated in the hydroxide form and selected trace elements can be scavenged and concentrated by ferric iron precipitation.
Analysis of Stochastic Hydrologic Systems
Authors: Chow Ven Te , Kareliotis S. J.
Published: February 2008

Hydrologic phenomena are in reality stochastic in nature; that is, their behavior changes with the time in accordance with the law of probability as well as with the sequential relationship between the occurrences of the phenomenon. To analyze the hydrologic phenomenon, a mathematical model of the stochastic hydrologic system to simulate the phenomenon must be formulated. In this study, a watershed is treated as the stochastic hydrologic system whose components of precipitation, runoff, storage, and evapotranspiration are simulated as stochastic processes by time series models to be determined by correlograms and spectral analysis. The hydrologie system model is then formulated on the basis of the principle of conservation of mass and composed of the component stochastic processes. To demonstrate the practical application of the method of analysis so developed, the upper Sangamon River basin above Monticello in east central Illinois is used as the sample watershed. The watershed system model so formulated can be employed to generate stochastic streamflows for practical use in the analysis of water resources systems. This application is of particular value in the economic planning of water supply and irrigation projects, which is concerned with the long‐range water yield of the watershed.
Vegetation and Watershed Shape
Authors: Magorian Thomas R.
Published: February 2008

The length L of vegetated first order watersheds developed by fluvial erosion is related to the width W by L = W2/RU, where R is 3 for converging random walks of step size U, whose observed mean is 3 meters for normal dendritic drainage and 40 meters for basins over 300 meters long that drain directly into third or higher order streams. Bare soil watersheds show the relation L = 0.4 W.
Multistage Marginal Cost Model of Investment‐Pricing Decisions: Application to Urban Water Supply Treatment Facilities
Authors: Riordan Courtney
Published: February 2008

An attempt is made to apply a previously developed general model of investment‐pricing decisions to the particular problem of choosing the timing and sizes of additions to capacity in urban water supply systems. On the basis of empirical data, typical but hypothetical cost and demand curves for water supply are defined and incorporated into the model. The model is then solved under varying assumptions with regard to rate of growth in demand, the level of the discount rate, and the length of the planning horizon. The results are compared in terms of their efficiency with results that could be expected from conventional approaches to the problem by employing certain arbitrarily assumed schemes of average cost pricing combined with rules of thumb criteria for choosing the size and timing of capacity investment.

The major conclusions reached are that at present we do not have the empirical data necessary to effectively implement the general model in the water supply area and that the results do suggest that the multistage marginal cost approach toward planning and operating urban water supply systems might be 10–20% more efficient than traditional average cost approaches.
Optimal Capacities for a Multireservoir System Using the Linear Decision Rule
Authors: Nayak Satish C. , Arora Sant R.
Published: February 2008

A chance constrained formulation of a multireservoir system is considered. Minimum and maximum release requirements, minimum pool level, and minimum freeboard capacity are specified by the management for each reservoir. The management also specifies the maximum probabilities beyond which these requirements are not violated. By proposing linear decision rules for the releases, the authors reduce the chance constrained formulation to an ordinary linear programing formulation. The linear decision rule states that the release from a reservoir during a given time period is defined by the difference between the ‘net initial storage’ and a ‘decision parameter’ for that reservoir during that period. The objective function considers only the total cost of reservoirs, because the primary objective is to meet the various given demands at a minimum cost. This model has been applied to the Minnesota River basin.
Convolution Approach to the Solution for the Dissolved Oxygen Balance Equation in a Stream
Authors: Bennett James P.
Published: February 2008

In terms of its response to biochemical oxygen demand (BOD) and dissolved oxygen (DO) inputs, a natural waterway may be treated as a system governed by the BOD and DO balance differential equations. Using the response of the DO balance differential equation to impulse inputs of DO and BOD, one can compute by convolution the response of the system to arbitrary BOD and DO inputs. The convolution technique requires numerical integration, but it is not a numerical solution to a differential equation; it therefore avoids the stability problems inherent in such solutions. The convolution technique permits consideration of longitudinal dispersion in systems that have time varying DO and BOD inputs, a situation that could previously be investigated only by numerical solutions to the basic differential equations. Examples show the capability of the convolution technique to reproduce field data and to match previously developed analytical and numerical techniques.
Comparison of Empirical Relationships between Pressure Head and Hydraulic Conductivity and Some Observations on Radially Symmetric Flow
Authors: Raats P. A. C. , Gardner W. R.
Published: February 2008

It is shown that the critical pressure head used by Bouwer is equal to the difference in matric flux potential at pressure heads zero and minus infinity divided by the hydraulic conductivity at pressure head zero. The critical pressure head and the saturated hydraulic conductivity are used to define a dimensionless pressure head, hydraulic conductivity, and matric flux potential. For six empirical relationships between pressure head and hydraulic conductivity, the associated matric flux potential and critical pressure head have been evaluated. The plots of the dimensionless hydraulic conductivity and mattic flux potential versus pressure head provide a clear basis for comparing the six models. A discussion of steady, p‐dimensional, radially symmetric flow (without gravity) illustrates the occurrence of the matrio flux potential and the critical pressure head in flow problems. Expressions are obtained for the steady flux, the maximum steady flux, and the change in steady flux as a function of changes in pressure head at two points. One‐dimensional, cylindrically symmetric, and radially symmetric flows are discussed as special cases. The results for the radially symmetric case suggest a new method for in situ determination of the hydraulic conductivity as a function of the pressure head.