bluuebunny/crossref_metadata_2025 huggingface dataset:
The magnetic diurnal variation of the horizontal force near the magnetic equator
Authors: Egedal J.
Published: February 2008

In a communication to the Edinburgh Meeting of the Association of Terrestrial Magnetism and Electricity, Dr. A. G. McNish has given the results from an analysis of the diurnal variations of the magnetic elements for five observatories in the Western Hemisphere. In this analysis also the diurnal variations at Huancayo are used. McNish points out that the establishment of the observatory at Huancayo “has led to the discovery of magnetic diurnal variations markedly different from those expected for such a region.” In using these new data from Huancayo the analysis of McNish has become of great value.
Critical frequencies, sunspots, and the Sun's ultra‐violet radiation
Authors: Allen C. W.
Published: February 2008

Monthly values of Rƒ0, the critical frequency relative to the critical frequency at zero sunspots, have been averaged for a number of stations and tabulated for the eleven‐year period 1937–47, The variations of Rƒ0 for the E‐, F1‐, and F2‐regions have been correlated with the solar data for sunspot‐numbers, bright Hα and Ca flocculi, faculae, and the coronal‐line intensity. The variations correlated are found to lag behind the sunspot‐number variations by the following parts of a month: Hα flocculi, 0.15; Ca flocculi, 0.31; Rƒ0E, 0.43; faculae, 0.56; Rƒ0F1, 0.66; Rƒ0F2, 0.68; coronal line, 0.87; and this is interpreted as giving the order of increasing mean life of the relevant solar features.

In the expression RS = (1 + bR) = (Rƒ0)n relating relative ultra‐violet intensity RS to sunspot‐number R and critical frequency, the adopted values of n and b for the regions E, F1, and F2 respectively are n = 4, 4, and 2, and b = 0.0097, 0.0124, and 0.0200. Values of n determined from the relation between critical frequency and the Sun's zenith‐distance were 3.72 for the E‐region, and 4.90 for F1.

The values of Rƒ0F2 are shown to vary with time, season, and station. The noon values however do not vary greatly and are generally close to the diurnal mean. A method of choosing stations reasonably free from the F2‐anomaly is given, and the recombination and electron‐decay coefficients are determined from these stations. The number of quanta per cm2 per sec outside the Earth's atmosphere at zero sunspots is given as: E, 5 × 108; F1, 1.9 × 109; and F2, 2.3 × 109.
Using a digital computer to estimate the effects of urban development on flood peaks
Authors: James L. Douglas
Published: February 2008

The digital computer program based on water balance methods and known as the Stanford Watershed Model was used to develop a long‐term continuous hydrograph (1905–1963) for Morrison Creek, Sacramento County, California. By varying constants describing the physical conditions within the watershed according to the amount of urban development and channel improvement within the tributary area, a number of continuous hydrographs were developed. A set of curves was developed from these hydrographs that made possible an estimate of flood peak by frequency for any combination of percentage of area urbanized, percentage of channels improved, and tributary area. An analysis was also made of the effects of urban development on runoff volumes and on the distribution of runoff during the year.
Interflow in claypan soils
Authors: Minshall Neal E. , Jamison V. C.
Published: February 2008

Storm runoff amounts from drainage areas of several square miles have often been estimated by direct application of runoff data from small plots and single‐cover water‐sheds. Data presented here attest to the existence of gains from interflow or quick‐return flow on midwest claypan soils under conditions of high antecedent soil moisture. Lesser storm periods with low antecedent moisture conditions show transmission losses on these same areas. For these reasons, weighted plot runoff cannot be accepted as a true representation of watershed runoff. Further evidence of interflow and its evaluation was obtained in 1963 on small irrigated plots at the University of Missouri Experiment Station Farm near McCredie, Missouri. These studies will be continued for another year or two.
A method for analyzing a drawdown test in anisotropic aquifers
Authors: Hantush Mahdi S. , Thomas Robert G.
Published: February 2008

A procedure using data from tests with a sufficient number of observation wells is presented herein for determining the transmissivity in any direction and the storativity of a homogeneous anisotropic nonleaky aquifer. The procedure assumes that the distribution of the observation wells is such that the elliptical shape of an equal drawdown curve during pumping or of an equal residual drawdown curve during recovery is so clearly delineated as to make possible a graphical determination of the major and minor axes of these ellipses. The method is developed primarily for analyzing recovery data from such tests. It can be used, however, for analyzing data from the pumping period. (Key words: Groundwater; hydraulics; wells)
Computation of optimum realizable unit hydrographs
Authors: Eagleson Peter S. , Mejia‐R Ricardo , March Frederic
Published: February 2008

The Wiener‐Hopf theory of optimum linear systems is applied to the determination of the stable pulse response of a monotone hydrologic system from coincident records of input and output in the form of discrete time series. In application to the rainfall runoff system, linear programming methods are used in the solution of the Wiener‐Hopf equations to obtain physically realizable unit hydrographs.
Statistical description of river networks
Authors: Scheidegger Adrian E.
Published: February 2008

A scheme for the statistical description of the geometry of a river network can be devised by focusing attention on the statistics of junctions. The statistics of a river network can also be regarded as the outcome of a stochastic branching process. The connection between the two possible statistical descriptions of river networks is given and, as an example, the case of a river network that has a constant bifurcation ratio (‘Horton net’) is discussed.
A socially optimum pricing policy for a public water agency
Authors: Brown Gardner , McGuire C. B.
Published: February 2008

A simple model is developed for determining the socially optimum price to charge locationally differentiated irrigation districts for both surface and groundwater supplies. Steady‐state conditions are assumed for groundwater conditions and water demand functions. A divergence between social and private optimums arises from the existence of unadjudicated rights to groundwater supplies. The social optimum can be achieved by an appropriately conceived taxing policy. Water prices, tax rates, and optimum lift levels are estimated for seven irrigation districts, members of a master water agency.
On the topology of river nets
Authors: Scheidegger A. E.
Published: February 2008

Graph theory can be applied to the topology of river systems. Such applications, in particular, show how the possible different river systems of a given order can be enumerated.
Effects of a monolayer on reservoir temperature and evaporation
Authors: Bartholic Jon F. , Runkles Jack R. , Stenmark Ernest B.
Published: February 2008

Data collected specifically to evaluate the increase in the water temperature in a reservoir due to the presence of a monolayer showed an increase in temperature not only at the surface but also at greater depths. This increase in temperature must be accounted for in predicting the reduction in evaporation by monolayers. Use of values for the increase in temperature predicted from the combined energy‐budget mass‐transfer method indicates a decrease of 8 to 14% in values for evaporation reduction as estimated by the simplified Bureau of Reclamation method, which does not account for the rise in temperature. An approach to predicting the increase in reservoir temperature and the reduction in evaporation as applied to one reservoir gave values for the temperature increase close to those measured.
A study in the economics of water quality management
Authors: Johnson Edwin L.
Published: February 2008

Several methods of allocating waste reductions among dischargers are available to water pollution control administrators. The most recent addition to this collection is the effluent charge. In this study comparisons were made among two effluent charge schemes, a least‐cost allocation and a more conventional uniform removal approach to load allocation in the attainment of several water quality improvement goals. The results indicate that the effluent charge concept should be seriously considered as a means of attaining water quality improvement and that such a scheme is capable of achieving improvements at a cost approaching that of the least costly plan. The impact on the regional economy is not expected to be significantly different under any of the schemes studied. However, the efficiency and equity characteristics of the effluent charge techniques appear superior to those of more conventional techniques. Additional studies in the application of charges are needed to cope with differential charges related to dynamic waste discharge situations, to describe discharger response more fully, and to define administrative problems and costs. (Key words: Economics; estuaries; planning; quality of water; waste disposal; water management; water resources)
Use of thermal model to investigate the theory of transient flow to a partially penetrating well
Authors: Javandel I. , Witherspoon P. A.
Published: February 2008

A thermal model constructed from a slab of steel has been used to investigate the theory of transient flow to a partially penetrating well in a confined aquifer of infinite radial extent where there is no leakage. Families of type curves have been prepared from the theoretical solution for tenth, quarter, and half penetration. Experimental results from the thermal model using the same penetrations are generally in very good agreement with the appropriate theoretical solution. This demonstrates the usefulness of the thermal model in studying transient flow problems. It is concluded that this experimental work has provided independent proof of the validity of the theoretical solution for the effects of partial penetration. (Keywords: Groundwater; hydraulics; wells)
An extension to the Thomas‐Fiering Model for the sequential generation of streamflow
Authors: Harms Archie A. , Campbell Thomas H.
Published: February 2008

An extension to an algorithm for the sequential generation of nonhistoric stream‐flow, previously used by Thomas and Fiering, is suggested. The distinguishing features of this model are preservation of (1) normal distribution of annual flows; (2) log‐normal distribution of monthly flows; (3) correlation between annual flows; and (4) correlation between monthly flows. This model has been applied to two representative Pacific Northwest rivers. A graphical examination of the results suggests that this model provides an authentic representation of streamflow.
Investigation of the technical feasibility of storing fresh water in saline aquifers
Authors: Esmail Omar J. , Kimbler Oscar K.
Published: February 2008

Preliminary studies indicate that the underground storage of fresh water in saline aquifers may be feasible from a technical viewpoint. Such a process would involve injection of fresh water, storage until needed, and subsequent production from the same well. This work, based upon theoretical considerations and model studies, leads to a computer technique by means of which the recovery of stored fresh water may be estimated. Calculations involving five hypothetical aquifers indicate recoveries ranging from 25 to 85%, depending upon aquifer and fluid properties. Loss of fresh water as a result of both dispersion (mixing) and gravitational segregation was considered. Results obtained in porous flow models indicate that gravitational segregation is significantly retarded by the development of a mixed zone. Such a zone is developed naturally during injection and production as a result of fluid movement and to a lesser degree during the storage portion of the cycle as a result of diffusion. Economic considerations and well problems were not treated in the study.
A comment on Horton's law of stream numbers
Authors: Smart J. Samuel
Published: February 2008

Horton's Law of Stream Numbers is shown to be internally inconsistent in the following sense: If there exists a large channel network of order S, with stream numbers that satisfy Horton's Law exactly, then the mean stream numbers for lower order networks contained in the large one will show definite deviations from Horton's Law. These mean stream numbers can be expressed by a recursive formula, which involves the probabilities Pij that a stream of order i terminates in a stream of order j > i. Reasonable assumptions about the nature of the Pij suggest that Horton curves (log Nk versus k) for the small order basins should be concave upwards, a result which is in general agreement with observation.
Lysimeter and watershed evapotranspiration
Authors: Mustonen Seppo E. , Mcguinness J. L.
Published: February 2008

A statistical model was derived for permanent grass lysimeter evapotranspiration (ETL), using lake evaporation, soil moisture, and precipitation as independent variables. Measured annual ETL was substantially greater than ET derived from water budget estimates on small watersheds. Differences in the ETL rate for permanent grass and grain crops were greatest at grain planting time when the ground was bare. ETL fell to about one‐half of normal when hay was cut and recovered to normal in about one month.
Simulation of Great Lakes Basin water supplies
Authors: Megerian Edmond , Pentland Ralph L.
Published: February 2008

The basic concept utilized in the simulation study is to evaluate statistically the recorded supplies to isolate the two components assumed to constitute the basin water supply: (1) that portion of the supply that is considered random, owing to chance interaction of unpredictable meteorological elements, and (2) that portion of the supply that is the result of the persistence due to natural storage in the lakes, soil, bedrock, and snow over the drainage basin. In this study, consideration was also given to the relationship between supplies in neighboring basins. These factors were used to formulate mathematical models for simulation of supplies to all of the Great Lakes simultaneously. Extensive statistical tests have been used to ensure that the statistical parameters and the time series characteristics of the simulated data resemble those of the recorded data.
Advective influences on the reduction of evapotranspiration in a coastal environment
Authors: Nixon P. R. , Lawless G. P.
Published: February 2008

Incoming air from an ocean may either supply heat to a land area or serve as an energy sink. A marked example of the energy sink phenomenon occurs in a coastal valley of California. Advective cooling resulted in much lower evapotranspiration than amounts reported for interior locations during the two months studied, July and September. Evapotranspiration from irrigated ryegrass was equivalent to about 2/3 of net radiation on clear days. This ratio is lower than the 8/10 or 9/10 commonly observed in humid interior areas and is much lower than amounts reported for interior desert conditions. Overcast days having low net radiation did not produce amounts of evapotranspiration that were proportionally as low. This observation indicated that there was a trade off beween radiation and advection under these coastal conditions where a critical balance existed between air and surface temperatures.
Spatial distribution of heavy storm rainfalls in Illinois
Authors: Huff F. A.
Published: February 2008

An 11‐year continuous record from 49 recording rain gages on 400 square miles in central Illinois has been used to derive characteristic area‐depth relations in heavy rainstorms for storm periods of 30 minutes to 48 hours on areas of 50, 100, 200, and 400 square miles. First, eight general equations were statistically tested to determine the most appropriate fitting method for the area‐depth curve. Over‐all, an equation relating rainfall depth to the square root of the area received the highest score. However, the equation that fit best was found to vary with areal size, mean rainfall, and storm duration, which, in turn, reflected general trends in relative variability and skewness of the rainfall spatial distribution. Because of the high degree of variability in the area‐depth relation between storms, the analytical results have been presented as probability distributions for given sets of conditions with respect to area, storm duration, and rainfall volume. Thus, the user is provided with both average curves and curves applicable to more extreme patterns of storm rainfall.
Statistical tests for common bankfull frequency in rivers
Authors: McGilchrist C. A. , Woodyer K. D.
Published: February 2008

Two statistical tests are described for investigating the claim that rivers exceed bankfull level with a common frequency. The first test is necessary to demonstrate that vertically adjacent bench level categories at a site are separate in terms of expected recurrence intervals. The second test examines the homogeneity of bankfull frequencies from site to site for each bench level category. The tests were used to examine data from nine stream gaging sites in New South Wales, Australia. It was shown that three distinct bench levels could be identified in the field. The bankfull frequencies associated with the present flood‐ plain level were shown to form a homogeneous population of bankfull frequencies.
A Case Study in Income Redistribution from Reservoir Construction
Authors: James L. Douglas
Published: February 2008

Because water resources investment has been evaluated from the economic efficiency objective, benefit‐cost analysis has been criticized as ignoring other goals. Benefit and cost data collected for Dewey Reservoir in the Appalachian Mountains of Eastern Kentucky were used to determine the incidence of benefits and cost among income intervals. Recreation as a project purpose proved more effective in redistributing income than flood control. Weighting the income maximization and income redistribution objectives according to the value judgment that income taxes collected represent equimarginal sacrifice showed income redistribution benefits to equal 18.2% of efficiency benefits. The percentage would be lower in higher income areas.
Flow of Ground Water Adjacent to Small, Closed Basins in Glacial Till
Authors: Williams Roy E.
Published: February 2008

During a recent field investigation, the flow of ground water was examined in the vicinity of three closed basins in glacial till in an area receiving approximately 34 inches average annual precipitation. Piezometric data indicate that during the period of study one of these basins was continually a ground‐water discharge area, whereas the others alternated between recharge and discharge. The water table rose adjacent to all three of the basins at some time during the study. Comparison of hydrographs of piezometers, precipitation data, and the level of the marshes within the closed basins indicates a variable effect of precipitation on fluid potential and marsh level. Basin area and shape influence the alternation of a given basin between recharge and discharge conditions. Water quality data suggest that all three of the basins examined have had either surface water or ground‐water outlets at some time, although not during the period of study.
Conversion of Hardwood‐Covered Watersheds to White Pine Reduces Water Yield
Authors: Swank W. T. , Miner N. H.
Published: February 2008

Mixed mature hardwoods were cleared from two Southern Appalachian experimental watersheds, and the areas were planted with eastern white pine in 1956–1957. Once the pine crowns began to close, streamflow steadily declined at a rate of 1 to 2 inches per year. By 1967, water yield was 3.7 inches less from a 10‐year‐old pine stand on a south‐facing watershed than expected water yield from the original hardwood forest. Most of the water yield reduction occurred during the dormant season and was attributed mainly to greater interception loss from white pine than from hardwoods. Because interception differences increase as white pine matures, an even greater reduction in streamflow is expected.
Assessing Impacts of Declining Water Quality on Gross Value Output of Agriculture, A Case Study
Authors: Pincock M. Glade
Published: February 2008

The methodology for assessing salinity damages is still in the development stage. This study develops an economic analysis of the effects of different levels of water quality on output and income for irrigated agriculture. First, a procedure for estimating physical crop losses due to salinity was summarized from the literature. Second, published enterprise and farm budgets were adjusted to show damages that might be expected for a specific irrigation project. A change in water quality, of the magnitude studied, did not indicate an adjusted cropping pattern in response to deteriorated water quality.
Using Analytical Methods to Develop a Surface‐Runoff Model
Authors: Betson Roger P. , Tucker Russell L. , Haller Faye M.
Published: February 2008

By using analytical methods, successive restrictions were imposed on a mathematical version of the U. S. Weather Bureau's graphical surface‐runoff model to develop an analytical model that expresses the API‐runoff relations with two equations and five coefficients. The analytical model is similar in concept to the graphical model in that both relate rainfall, week number, and the API measure to surface runoff. The concise relations of the analytical model, however, can be rapidly derived from a historical storm list by computer. When tested, runoff relations, derived with the analytical model over selected watersheds, predicted surface runoff from those watersheds somewhat better than the regional, graphical relations developed for the Valley.
Computer Experiments with Fractional Gaussian Noises: Part 2, Rescaled Ranges and Spectra
Authors: Mandelbrot Benoit B. , Wallis James R.
Published: February 2008

Continuing the preceding paper, we shall report on computer experiments concerning the ‘rescaled range’ and the spectrum of fractional Gaussian noise.
Some long‐run properties of geophysical records
Authors: Mandelbrot Benoit B. , Wallis James R.
Published: February 2008

A variety of geophysical records are examined to determine the dependence upon the lag s of a quantity called ‘rescaled range,’ denoted by R(t, s)/S(t, s). If there had been no appreciable dependence between two values of the record at very distant points in time, the ratio R/S would have been proportional to s0.5. But, in fact, as first noted by Edwin Hurst, the R/S ratio of hydrological and other geophysical records is proportional to sH with H ≠ 0.5. Hurst's original claims must be tightened and hedged, and his estimates of H must be discarded, but his general idea will be shown to be correct. We have shown elsewhere that this behavior of R/S means that the strength of long‐range statistical dependence in geophysical records is considerable.
Evaluation of the rate of flow through porous media using electrokinetic phenomena
Authors: Abaza Mohamed M. I. , Clyde Calvin G.
Published: February 2008

There is a need for some means of direct measurement of the rate of flow through porous media to supplement the traditional indirect measurements, such as the use of tracers and the measurement of hydraulic gradient. An analytical relationship is developed that relates the rate of flow through porous media to the streaming current I and streaming potential E induced by the flow. Thus, a measurement of either E or I would give a value related to the rate of flow. Laboratory experiments were conducted to test the analytical relationship. The effects of the concentration of dissolved salt in the percolating solutions, the size of the particles forming the beds, and the temperature of the solution on the streaming current and the streaming potential are determined. The analytical relationships, together with the experimental work, form the basis of a method of measuring the rate of flow through porous media.
Some Applications of Cross‐Spectral Analyses in Hydrology: Rainfall and Runoff
Authors: Rodríguez‐Iturbe Ignacio , Nordin Carl F.
Published: February 2008

Coherence and partial coherence between cyclic components of hydrologic time series show strong correlations among annual oscillations in precipitation and runoff for stations located in the Pacific Coast region of the United States. To distances of 1000 km the annual cycle of precipitation can be considered practically the same for all stations. Similar relations exist between records of streamflow, but the coherence is less because of variable watershed characteristics, evaporation, storage, and other factors influencing runoff.
Similarity Approximation for the Radial Subsurface Flow Problem
Authors: Drake R. L. , Molz F. J. , Remson Irwin , Fungaroli A. A.
Published: February 2008

A useful mathematical technique in the study of radial flow of underground water is the application of similarity transformations, such as Boltzmann's transformation. The transformations lead to approximations that are shown to be valid if certain physical parameters satisfy given limiting conditions.

A nonlinear partial differential equation is formulated describing the radial flow of soil moisture. A similarity approximation is used to transform the partial differential equation into a nonlinear ordinary differential equation. Criteria by which to judge the applicability of the similarity approximation are derived.

Several monotonicity properties of the transformed moisture as a function of the similarity variable are derived. The properties are used to develop a numeric procedure for the solution of the transformed equation. The procedure is used to study the radial flow of soil moisture to a cylindric sink for diffusivities which vary linearly, quadratically, and exponentially with soil moisture. The solutions show that the moisture front steepens with increasing nonlinearity.
Fe, Mn, Ni, Co, Sr, Li, Zn, and SiO2, in Streams of the Lower Kansas River Basin
Authors: Angino E. E. , Galle O. K. , Waugh T. C.
Published: February 2008

An attempt is made to ascertain the background levels and to measure seasonal variations of selected trace and minor elements in the major streams of the Lower Kansas River Basin. Knowledge of the trace element chemistry of river waters is becoming increasingly more important as the rate of use of stream waters increases. Excepting the case of strontium, no strong relation between trace element concentration and geology lithology was noted. To ascertain properly trace element background levels in streams, long‐term sampling covering at least one seasonal cycle is essential. Variations in drainage basin geology have only a minor controlling influence on the trace element geochemistry of the wastes studied.
Optimizing Investment in Flood Control and Floodplain Zoning
Authors: Whipple William
Published: February 2008

Recent governmental actions have accentuated floodplain zoning as an alternative to structural flood control. Optimization of investment between these alternatives requires consideration of project‐induced development (economic development which would not occur if the project were not built) and site income (the return to the owner of new construction in the floodplain net of the cost of their development). These concepts are used to develop quantitative criteria applicable to determining to what extent zoning is practicable and to determining a correct benefit‐cost ratio for the optimum solution. Results indicate that previously existing methods that do not take account of damages to project‐induced growth may give unduly high benefit‐cost ratios. It should normally be expected that a combination of flood control and zoning will be most productive.
Time‐capacity expansion of urban water systems
Authors: Scarato Russell F.
Published: February 2008

This paper presents a minimum cost method to time and size water system component expansion to meet an exogenously determined growth rate. The method analyzes the economic impact both of the economies of scale in construction and of the real cost of capital. The result is a capacity expansion model which determines when and how much excess capacity should be installed to meet increasing demands. The economic effects of timing and sizing decisions on total costs are plotted for various interest rates and levels of economies of scale. The paper demonstrates that the costs of expansion are sensitive to the increase in demand specific to the facility being planned and that the design capacity must be set individually for each separable water system component according to its particular cost function. These findings suggest that the standard practice of designing excess capacity in a water system to meet a fixed future demand (i.e., 25‐year system) should be revised.
Effect of rainfall variability on streamflow simulation
Authors: Dawdy D. R. , Bergmann J. M.
Published: February 2008

Three recording rain gages in a 9.7‐square‐mile basin in southern California were used with a deterministic rainfall‐runoff model to simulate flood hydrographs and peaks and to assess the effects of data errors on simulation results. Bias in the estimation of effective basin rainfall seemed to result in curve fitting parameter adjustments which compensated for the bias. The combined effects for a storm of both difference in the time distribution of rainfall at different points and spatial variability of rainfall volume over the basin limit the possible accuracy of simulation results. The use of a single rain gage on a basin with this hydrology can at best be expected to predict peak discharge with a standard error of estimate on the order of 20%.
Soil movement on irregular slopes
Authors: Young Robert A. , Mutchler Calvin K.
Published: February 2008

Soil loss and runoff were measured from concave, uniform, and convex slopes subjected to simulated rainfall. Fluorescent glass particles and microrelief measurements were used to determine soil movement patterns in the slopes. For slopes of equal average steepness, a concave shape greatly reduced the total sediment loss in comparison with that from either a uniform or convex slope. Average slope steepness was not a good indicator of soil delivery past a given point except for a uniform slope. In general, soil losses from irregular slopes depend on the steepness of a short section of that slope immediately above the point of measurement. Soil movement off the plots was primarily transport by raindrop splash to a rill system and then transport down the slope by runoff in the rill system. A breakdown of the rill system occurred on the bottom of the concave slopes because of decreasing local steepness, resulting in sheet flow and sediment deposition.
Total albedo of Great Lakes ice
Authors: Bolsenga S. J.
Published: February 2008

The total (0.3‐3.0μ) albedo of various types of ice common to the Great Lakes ranged from 10% for clear ice to 46% for snow ice at solar altitudes ranging from 32 to 40 degrees. Explanations are given for similarities between the albedo of pancake (31%) and slush curd ice (32%), and slush (41%) and brash ice (41%).
Dynamic Programing for the Optimal Sequencing of Water Supply Projects
Authors: Butcher William S. , Haimes Yacov Y. , Hall Warren A.
Published: February 2008

A minimum present cost strategy for investment in water projects is derived. An increase in demand for water is considered to be supplied by a number of projects that have an indefinite life. The optimum sequence of installation of these projects is determined by (1) the shape of the water demand/time relationship, (2) the appropriate interest rate, and (3) the relative costs and capacities of the facilities from which a selection is made. A general method to derive the optimum sequence of construction is developed using dynamic programing. Examples of the use of the technique are given.
Atmospheric water balance and hydrology of the Upper Colorado River Basin
Authors: Rasmussen James L.
Published: February 2008

The atmospheric water balance over the upper Colorado River is evaluated twice daily for the seven winter seasons 1957–1963. The atmospheric water balance yields the exchange of water and water vapor at the earth‐atmosphere interface through the observation of the spatial and time distributions and fluxes of water vapor in the atmosphere over the basin. The quantity precipitation minus evaporation is determined as a residual of the computation and is accumulated for daily and seasonal values. In addition, a natural period analysis is performed; the natural periods are delineated by homogeneity in the parameter precipitation minus evaporation. The dry periods are shown to exhibit a seasonal trend in evaporation rate as well as decay of evaporation rate with time within periods. Duration is shown to be the dominant factor in storm yield and the occurrence of a few large storms delineates the relatively wet from the relatively dry winters. Finally, the wintertime accumulation of water over the basin and the resulting annual runoff are shown to be highly correlated.
Deuterium variations in an annual snowpack
Authors: Judy Clark , Meiman James R. , Friedman Irving
Published: February 2008

Deuterium samples taken during the 1967–1968 snow year in the Rocky Mountains of Colorado indicate that metamorphism and melt of the snowpack greatly reduce the large initial variability in deuterium content of individual snowfalls. New snow values ranged from −229‰ to −106‰. D relative to SMOW (Standard Mean Ocean Water). The range in the snowpack profile on May 3, 1968, was −182 to −158. This homogenization would reduce the problems involved in following snowmelt through the hydrologic system.
Recurrence Intervals between Exceedances of Selected River Levels: 3. Estimation and Use of a Prior Distribution
Authors: McGilchrist C. A. , Chapman T. G. , Woodyer K. D.
Published: February 2008

The frequency of exceedance of certain identifiable levels in the banks of rivers has been shown to be approximately constant from site to site in New South Wales. The parameters of a model which describe this frequency at a site can therefore be regarded as a random selection from a prior distribution which describes the variations from site to site. By assuming an appropriate form for this prior distribution and estimating its parameters from data at a number of sites, the observed record at a particular site in the same region can be extended.
Statistical Roughness Parameter as Indicator of Channel Flow Resistance
Authors: Chiu Chao‐Lin , Rubio Almanzar
Published: February 2008

In an analysis of field data of four natural rivers a statistical, large‐scale roughness parameter has proved effective as an indicator of the channel resistance to the flow when the Froude number based on the mean annual flow is larger than about 0.2. The parameter is derived from the concept that the irregular shape and slope of an irregular alluvial channel may be considered as a result of the random walk of imaginary ‘particles’ along the channel bed. It is the so‐called diffusion coefficient which, according to the stochastic theory of the diffusion process, is normally defined in a diffusion equation as the mean square or the variance of the displacement of the particles during a step of random walk over a constant time interval of length Δt divided by 2 Δt. In the present study, however, Δt represents a constant distance interval instead. The parameter proved to have characteristics similar to those of another large‐scale roughness parameter that is derived by other investigators from concepts other than the statistical. This roughness parameter provides a new statistical geometric measure of the irregularities along the entire channel bed and sides that is related to the probability of channel geometry through the diffusion equation, which provides the conceptual basis for its use as a roughness parameter.
Comparison of Solutions of a Nonlinear Diffusion Equation
Authors: Brutsaert Wilfried , Weisman Richard N.
Published: February 2008

Four solutions of a general nonlinear diffusion equation are given. A numerical analysis serves as reference for one series solution and for two more simple approximate solutions. The accuracy of the methods is discussed and presented graphically; the results of the numerical analysis are given in tabular form. It was found that the usefulness of the two approximate solutions lies in their mathematical simplicity and the accuracy with which they describe infiltration.
Time Bias in Recreation Benefit Estimates
Authors: Cesario Frank J. , Knetsch Jack L.
Published: February 2008

Indirect methods are generally necessary to measure outdoor recreation benefits. A widely proposed technique involves estimating demand schedules using travel cost data as a proxy for prices. A major problem involved with this method as it has been applied is a serious conservative bias in the estimates, owing to the improper accounting of the constraint imposed by time costs on recreational visits. The bias is examined and corrections are suggested that could improve the estimates. The degree of ultimate improvement seems to depend on better data and on an understanding of the trade‐off function between time and cost outlays for this form of travel.
An Analysis of Ice Lens Formation
Authors: Takagi Shunsuke
Published: February 2008

A mechanism of ice lens formation is presented on the assumption that its main cause is the simultaneous flow of heat and water. The differential equations thus formulated are solved approximately by the use of a generalization of Goodman's integral method. The result is found to be not completely satisfactory when compared with an experiment. The following progress has however been made: (1) The existence of a solution to the differential equations of ice lens formation is demonstrated. (2) The solution exists for a very narrow range of initial water content determined by the amount of surcharge on the ice lens. The narrowness of the range probably accounts for the observed intermittence of lenses. (3) The Goodman technique or any generalization of it cannot yield a satisfactory solution of the problem. (4) A simplification of Portnov's method has been found. (5) The possibility of obtaining an exact solution for a short initial time interval arises when the independent variablesxandtare reduced tox/(t)½and (t)½, wherexis the vertical coordinate andtis the time. (6) With development of the mathematical method, improvements in the assumed mechanism, and refinements in the measurements of soil properties, we may be able to completely formulate frost heaving and thereby solve a long‐standing problem.
Fingero Imbibition in Artificial Replenishment of Ground Water Through Cracked Porous Medium
Authors: Verma A. P.
Published: February 2008

The present paper analytically discusses a theoretical model of groundwater replenishment in a cracked porous medium, with simultaneous occurrence of the phenomena of fingering and imbibition under certain conditions. We assume that the injection of water bodies is initiated by imbibition, and the ‘injected’ and ‘native’ water form two immiscible liquid phases of different salinities with small viscosity difference [Bear and Martin, 1965]. If we consider only the average behavior of fingering, we solve the nonlinear differential equation by a perturbation technique. An expression for the average cross‐sectional area occupied by fingers has been obtained.
Experiments on the Adsorption of Ammonium Ions by Clay Particles in Natural Waters
Authors: Toetz Dale W.
Published: February 2008

The situation where the counter ion NH4 on particulate matter establishes a dynamic equilibrium with other cations in surface waters was simulated experimentally by mixing a powdered subsoil and a montmorillonite, respectively, with diluted well water. Adsorption was demonstrated in one case, but the employed technique lacked the sensitivity needed to measure adsorption of NH4 at concentrations normally encountered in freshwater.
Measurement of Soil Moisture with a Portable Gamma Ray Scintillation Spectrometer
Authors: Mchenry J. Roger , Gill Angela C.
Published: February 2008

The measurement of soil or sediment density in situ by gamma ray attenuation [van Bavel, 1959; McHenry and Dendy, 1964] includes the soil moisture present. The change in total density of a soil with a change in moisture is small with respect to the bulk density of the soil. McHenry [1963] determined the moisture of sediments as a function of total density using the attenuation of transmitted gamma rays. A sensitivity of less than 2% moisture content was reported.
A Critique of Methods of Simulating Rainfall
Authors: Hall M. J.
Published: February 2008

Observations of drop size distributions in natural rainfall have shown that the range of drop sizes increases with increasing rainfall intensity. If a network of nozzles is used to generate artificial rainfall, an increase in working pressure increases the average intensity but decreases the range of drop sizes within the spray. This property has hindered the development of the rainfall simulator more than any other single factor. Alternative methods of simulating rainfall, which depend upon individual drop forming elements such as hypodermic needles for example, are capable of producing sprays with uniform drop sizes only. Such methods have been employed successfully in generating storm patterns involving both temporal and spatial variations in intensity for laboratory catchment studies. A general purpose rainfall simulator, combining control of application rates in both space and time with the reproduction of the drop size distributions and velocities of fall of drops observed in nature, has yet to be developed.
Use of the Mass Balance Method for Examining the Role of Soils in Controlling Watershed Performance
Authors: Rawitz E. , Engman E. T. , Cline G. D.
Published: February 2008

A two year preliminary study of the water balance of a 16.2‐hectare watershed in Pennsylvania showed that spring and summer storms produced practically no overland surface runoff during the storms, but these storms did produce typical hydrographs having all the characteristics usually attributed to surface runoff. Less than 5% of the rainfall, and one third or less of the total runoff appeared as storm runoff. Since virtually all the water eventually reaching the stream channels infiltrated the soil and most of it percolated through the soil, the properties of the soil and the amount of water stored in this layer emerge as the most important regulators of runoff in the system.
Demand for Water under Dynamic Conditions
Authors: Hanke Steve H.
Published: February 2008

An empirical analysis of the effects on residential water use of changing from a flat rate price structure to a metered one is presented. Time series data, for the first time, are used to study the dynamics of residential water demand. The results include the observations that: (1) sprinkling demands were reduced by the introduction of meters, with actual sprinkling being greater than the calculated ideal under flat rates and less than ideal under metered rates; (2) sprinkling use not only declined with the introduction of meters but subsequently continued to decline; (3) domestic demands (in‐house) were reduced by 36% after meter installation; and (4) domestic demands stabilized at these lower levels. The evidence generated by the analysis demonstrates that water users do not return to their old use patterns after meters are installed, and that metering results in a permanent and significant improvement in water use efficiency.
Vertical Temperature Structure and Water Surface Heat Exchange
Authors: Edinger John Eric
Published: February 2008

A heat balance between the time change in heat storage and net vertical heat transfer within a water column by vertical dispersion is assumed. The average surface temperature and its amplitude is related to surface heat exchange using the concept of equilibrium temperature. This results in a set of relationships that can be used to estimate the seasonal time varying vertical temperature structure of a water body from meteorological data.
A Note on Bacterial Growth Around a Recharge Well at Bay Park, Long Island, New York
Authors: Vecchioli John
Published: February 2008

Highly treated sewage plant effluent is being injected into a deep sand aquifer at Bay Park, Long Island, New York. High bacterial counts are observed in water pumped initially from the injection well after recharge termination, even though the injected water generally meets potable standards. Moreover, the number of bacteria recovered during pumping is much larger than the number injected. This suggests a growth of bacteria in the aquifer around the injection well, possibly in part on a filter mat of organic material formed at or near the aquifer‐gravel pack interface during injection. Continued pumping results in lower counts until virtually bacteria‐free water is produced. However, whenever pumping is stopped and restarted, the initial slug of water pumped shows higher counts than before shutdown. Apparently the surging action of the water dislodges bacteria that otherwise would not enter the well.
Small Sample Properties of H and K—Estimators of the Hurst Coefficient h
Authors: Wallis James R. , Matalas Nicholas C.
Published: February 2008

Seasonal differences in long‐term persistence (h > 0.5), were found for 25 streams in the Potomac River basin. Two statistics, H and K, used as estimators of h were found to have differing small sample properties. K was found to have less variance but a greater positive bias than H. However, the Hurst phenomenon, in which H and K values differ from the expected values for independent series, was confirmed for the Potomac River basin streamflows. Neither marginal distribution nor biased transience appear to be viable explanations for the differences between observed and independent or short memory simulated sequences. For the Potomac basin, the explanation of h > 0.5 can only be attributed to the nature of the correlation structure of the observed series.
The Potential Use of Tree Rings in Hydrologic Investigations in Eastern North America with Some Botanical Considerations
Authors: Phipps Richard L.
Published: February 2008

Trees add a new growth layer, or ring, each year. Because growth is controlled in part by environment, analysis of tree rings can potentially yield information concerning past hydrologic (or other environmental) conditions. The present state of understanding of the relationship between tree growth and the hydrologic environment in the eastern United States does not yet allow detailed estimates of past environments from tree rings. It does appear though, that within the near future it will be possible to estimate certain hydrologic parameters in space (between gaging stations) from tree growth phenomena. For the present, however, examination of tree rings is most useful in hydrologic studies for dating of events.
Simulation and Evaluation of Complex Water Systems Operations
Authors: Moran P. A. P.
Published: February 2008

The production of long artificial series of multiple streamflows given for say monthly or weekly values is considered, taking into account the usually very nonnormal distributions involved, serial dependence, seasonal variation, and the correlation between different streams. It is proposed that the distribution of flows for a given stream and month be fitted by gamma type distributions, and that these distributions then be transformed to obtain normally distributed variates. A separate canonical correlation analysis for each successive pair of months enables one to set up a nonstationary seasonally varying Markovian process that is then transformed back into the original nonnormal variates. The uses of such simulated series for calculating the probability behavior of a system of dams and for the approximate optimization of their operation is described, together with the estimation of standard errors.