bluuebunny/crossref_metadata_2025 huggingface dataset:
We can solve our water problems
Authors: Fox Irving K.
Published: February 2008

Our water problems may be thought of as occurring in three major areas. One problem area is the urgent need of maintaining a continuously advancing science and technology, especially in water quality management. A very difficult and complex problem area is that of balancing costs and returns from water development and use. It has proven to be uncommonly difficult to achieve a consensus on costs and returns, which, in turn, has often made it difficult to proceed with water programs. A third problem area stems from the inadequacy of water management institutions. Laws, policies, and organizational arrangements have not kept abreast of the requirements of a rising demand and an advanced technology. In recent years we have greatly improved our ability to deal with these water problems through advances in science and technology, better methods of economic analysis, and a deeper understanding of institutional factors. Recent actions by both government and private organizations reflect a determination to solve the problems that remain. Three key issues now merit priority attention, namely, (1) finding better ways of providing officials and the public with authoritative information; (2) establishing institutions capable of operating complex water management programs; (3) modifying public policy to improve the performance of private enterprise.
Temporal allocation of groundwater
Authors: Burt Oscar R.
Published: February 2008

A relatively simple economic model for allocation of groundwater in time is developed. The economic consequences of altering various parameters in the model are examined with respect to the effect on equilibrium stocks and rate of use. The concept of a conditional decision rule for stochastic groundwater recharge and the properties of the implied equilibrium are discussed. In its simplest form, the derived decision rule is to equate marginal net output with respect to rate of use to capitalized marginal net output with respect to water stocks.
Regression models for predicting on‐site runoff from short‐duration connective storms
Authors: Schreiber H. A. , Kincaid D. R.
Published: February 2008

On‐site runoff resulting from summer convective thunderstorms was studied in the Walnut Gulch Experimental Watershed, using 6− × 12−foot plots at 2 locations, based on 5 location‐years of data from 34 storms. Average runoff increased as precipitation quantity increased, decreased as crown spread of vegetation increased, and decreased as antecedent soil moisture increased. In a stepwise multiple linear regression equation, these independent variables accounted for, respectively, 72, 3, and 0.5% of the prediction variance. Considering regression equations for any one location‐year, storm amount or intensity always was significant, crown spread usually was significant, and antecedent soil moisture rarely was significant. In simple correlations, antecedent soil moisture was never related significantly to runoff. The equations developed appear valid for a set of thunderstorms with at least one‐sixth of maximum 5‐minute intensities exceeding 3.7 inches per hour. (Key words: Hydrology; runoff; thunderstorms)
Forecasting the levels of the Great Lakes
Authors: Decooke B. G. , Megerian B. G.
Published: February 2008

A description is given of the U.S. Lake Survey method of forecasting Great Lakes water levels. The method, in general, consists of determining a level for each month of a 6‐month forecast period on each of the Great Lakes by routing a predicted volume of water (Net Basin Supply) to each of the Great Lakes basins. The technique employed in prediction of the volume of the water consists of using multiple linear regressions based upon U.S. Weather Bureau precipitation and temperature data as predictors for the first month and trend predictors for the second through the sixth month. This technique results in forecasting of lake levels on the average from 15 to 40% closer to the recorded lake levels, in comparison with the technique that utilizes the long‐term average volume of water as the basis of projection. (Key words: Forecasting; water supply; Great Lakes)
Applications of factor analysis in study of chemistry of groundwater quality, Mojave River Valley, California
Authors: Dawdy D. R. , Feth J. H.
Published: February 2008

Factor analysis is applied to results of chemical analyses of 103 water samples from wells in the Upper and Middle Mojave River valley, San Bernardino County, California. Chemical analyses showed that there are three principal chemical types of water, calcium bicarbonate, sodium sulfate, and sodium chloride, as well as many mixtures of the three. Data were studied by factor analysis to learn the relative importance of each principal ion in determining the variations among the samples, and to examine the possibility of chemical equilibrium between aqueous and solid phases in the aquifers.

Most of the covariance in the system may be accounted for by variances of Ca+2, Mg+2, Na+1, SO4−2, and Cl−1. There is almost identical loading on the constituents Na+1 and Cl−1. The variance in chemical composition of the hydrochemical system is governed largely by sources of sodium chloride. None of the components is controlled by equilibrium between ions in the water and minerals in the aquifers. Concentrations of NO3−1 and F−1 vary independently of other constituents. Geographic distribution of statistical loadings of the principal constituents at individual wells does not reveal sources of the constituents, which must be deduced from geologic and hydrologic evidence. Factor analysis, however, furnished the critical information on chemical relationships basic to the deduction. (Key words: Geochemistry; groundwater; statistics; California)
On the meaning of the Dupuit and Pavlovskii approximations in aquifer flow
Authors: Irmay S.
Published: February 2008

Pavlovskii's method is applied to Dupuit's approximate solution of steady hydraulic flow of unconfined two‐dimensional plane or curved aquifers in uniform or nonuniform soils, on a horizontal or inclined impervious base. Graphs correlate the geometrical parameters. The error on the potential is about ¼%. The effect of end slopes, especially of the seepage face, may account for some 30% of the total discharge. In one‐dimensional flow the discharge is correct even in nonuniform and curving aquifers on a horizontal base and seemingly also on an inclined base. Girinskii's potential in nonuniform soils in Dupuit's approximation is replaced in the exact theory by two other potentials. (Key words: Groundwater; seepage; hydraulics)
Interception by eastern white pine
Authors: Helvey J. D.
Published: February 2008

Measurements of gross rainfall, throughfall, stemflow, and litter interception in three eastern white pine stands, age 10, 35, and 60 years, in the Southern Appalachians of western North Carolina, were used to derive regression equations for estimating throughfall, stemflow, and the sum of throughfall and stemflow from measurements of gross rainfall. Equations for total interception loss were derived by algebraically combining losses from the canopy and litter. These equations were used to predict total seasonal interception loss (I) from measurements of total seasonal rainfall (ΣP) and number of storms (N). Equations for the 10‐, 35‐, and 60‐year‐old stands are I = 0.05(N) + 0.08 (ΣP), I = 0.05(N) + 0.12(ΣP), and I = 0.06(N) + 0.18(ΣP), respectively. Total interception loss in white pine increased with stand age, and total loss from all pine stands studied exceeded losses calculated for mature hardwoods. During the dormant season, calculated monthly interception loss from mature hardwoods and white pine exceeded potential evapotranspiration calculated by the Thornthwaite method.
Unsteady, one‐dimensional flow over a plane—The rising hydrograph
Authors: Woolhiser D. A. , Liggett J. A.
Published: February 2008

The equations describing overland flow, in three nondimensional forms, are solved for the rising hydrograph by finite‐difference integration of the characteristic equations utilizing a characteristic net. A dry channel was used as an initial condition; the upstream and downstream boundary conditions were zero inflow and critical depth (or no condition for supercritical flow), respectively. A series solution is derived for flow in Zone A, the domain of determinacy of the initial conditions along t = 0. When compared with previous numerical, analytic, and experimental results, the results show that in general there is no unique dimensionless rising hydrograph for overland flow, but that for most hydrologically significant cases the kinematic wave solution gives very accurate results. A single dimensionless parameter was found to be a suitable criterion for choice between the complete equations or the kinematic wave approximation.
Optimization techniques for hydrologic engineering
Authors: Beard Leo R.
Published: February 2008

Optimization processes show considerable promise for a reasonable solution of the increasingly complex design and operation problems that occur in water resources engineering. Gradient methods of optimization should appeal to the engineer, because the methods can be used within the framework of traditional engineering analyses (e.g., multipurpose sequential routing or system simulation), where the components of the system can be changed in successive trials to obtain the best combination most rapidly. They can most easily be adapted to practical complex problems and appear to require minimum programming and computation time. Because of the large amount of computation involved, optimization procedures almost always require the use of high‐speed digital computers.
Analyzing subsurface flow systems with electric analogs
Authors: Bouwer Herman
Published: February 2008

Subsurface movement of water in hydrologic or engineering systems can be analyzed with direct analogs. These are analogs that directly simulate the transmission and storage properties of the soil as relevant parameters in the water movement process. Principles and techniques for constructing and operating analogs include calculation of resistance and capacitance values for network analogs, simulation of fixed, free, and infinite boundaries, inclusion of unsaturated flow, solution of quasi‐steady flow problems, analysis of diffusion‐type flow systems, simulation of horizontal and vertical flow systems, instrumentation, and data conversion. Direct electric analogs are relatively simple to build and use, and they enable solution of flow systems not amenable to mathematical analysis. There is, however, a limit as to the complexity of flow systems that direct analogs can handle, and a point is reached, where digital computers are more appropriate.
Development and testing of snow pack energy balance equations
Authors: Anderson E. A.
Published: February 2008

By making several minor assumptions and using an empirical technique in one situation, the energy balance of a snow pack can be computed on a continuous basis. Net radiation or its components, air temperature, dew‐point temperature, atmospheric pressure, amount of precipitation and its temperature, surface snow density, and a wind function that relates vapor pressure gradient to moisture transfer as a function of wind speed, must be either measured or estimated. Comparison of computed versus observed snow pack runoff and snow surface temperature for the Lower Meadow lysimeter studies of 1954 at the Central Sierra Snow Laboratory reveals good agreement. A model was constructed by combining the energy balance equations with relationships describing the other components of the snow accumulation and ablation processes. The Stanford Watershed Model is used to determine the time delay from when water leaves the snow pack to the streamflow gaging station. Tests of the model on 5 years of data from the Central Sierra Snow Laboratory resulted in a reasonable simulation of the observed mean daily flow hydrograph and seasonal areal snow cover plot. It is concluded that the model is at least a good approximation to the actual physical processes and should be a valuable tool in further snow hydrology investigations.
Isolation and characterization of hydrologic response units within agricultural watersheds
Authors: England C. B. , Onstad C. A.
Published: February 2008

To extrapolate hydrologic relations from small to large areas, a watershed can be partitioned by isolation of units of relative homogeneity with respect to soil type, landform, and land use that fall into a sequence compatible with the hydraulics of overland and subsurface flows. In basins where lithology is relatively uniform, processes of landform development and soil genesis are closely related. Degree of slope, topographic position, and water balance of a site affect the kind of soil and its land‐use capability. Hydrologic response units within complex watersheds are based upon areal and elevational distribution of soils as delineated on a hypsometric curve.
Theory of flow in aquicludes adjacent to slightly leaky aquifers
Authors: Neuman Shlomo P. , Witherspoon P. A.
Published: February 2008

The theory of flow in aquicludes that are adjacent to slightly leaky aquifers is presented for two cases: (a) aquicludes of finite thickness and (b) aquicludes of semi‐infinite thickness. By ‘slightly leaky’ we simply mean that when the aquifer is being pumped at constant rate, the drawdowns in the aquifer will be predicted by the Theis solution, even though some slight movement of water through adjacent confining beds occurs. It is assumed that flow is essentially horizontal in the aquifer and vertical in the aquiclude. On this basis, analytical expressions for drawdown in the aquiclude are developed for each case. The results are presented in the form of type curves that can be used for aquiclude evaluation. The effect of multiple‐well fields is considered in each case.
Point dilution methods of investigating ground water flow by means of radioisotopes
Authors: Drost Walter , Klotz Dietmar , Koch Arnd , Moser Heribert , Neumaier Ferdinand , Rauert Werner
Published: February 2008

To apply the point‐dilution method of measuring the rate of ground water flow by tracers, the distortion of the flow field by the well must be known. The distortion can be calculated with sufficient accuracy if the permeabilities of the aquifer, k3, of the gravel pack, k2, and of the well screen, k1, fulfill the condition k3 ≤ k2 ≤ k1. The tracer must be adequately mixed during the dilution procedure. Experiences obtained from model tests are applied in investigations in the field. By using peak‐to‐peak and total count methods in wells where vertical flow occurred, we could determine the depths and the rates of inflow and outflow, which relate to seepage under dams and water exploration. To determine the direction of ground water flow, a radio tracer was injected into a well‐screen section and, after having left the well‐screen, was detected by a collimated detector. The use of tracers that are fixed on the soil is advisable; 198Au, having been homogeneously distributed within the dilution volume initially, has proved most suitable. Strong vertical currents in the well represent a serious obstacle in field measurements of the rate and of the direction of ground water flow.
Horton's law of stream order numbers and a temperature‐analog in river nets
Authors: Scheidegger A. E.
Published: February 2008

Statements of Horton's law in Horton, Strahler, and consistent stream ordering systems are presented. A topological characterization of a ‘Horton net’ is given. It is then shown how the analog of ‘temperature’ can be defined in microcanonical ensembles of stream nets, based on an earlier representation of river nets by graphs (bifurcating arborescences).
The use of soil maps in the delineation of flood plains
Authors: Cain John M. , Beatty Marvin T.
Published: February 2008

Soil maps provide a tool for rapid, low‐cost delineation of river flood plains, based on the difference in morphology between soils frequently flooded and soils free of flooding. Very rare floods along the Mississippi River inundated over 99% of the soils that would be expected to flood but in addition flooded 7% of the terrace soils. Flooding predicted with soils information was compared with flooding predicted with an engineering study for small streams in a mature landscape in southwestern Wisconsin. For a 100‐year synthetic flood an agreement of ±4.5% was obtained. Comparison of flooding with soil types for a small stream in a recently glaciated landscape in southeastern Wisconsin indicated that alluvial soils flood frequently and, in addition, that soils with restricted drainage and soils of fluvial origin also flood frequently. Some of the data are inconclusive, owing to the lack of precise flooding information to serve as a basis of comparison. In areas where man‐made works do not appreciably alter the stream regimen and where extensive flood plain areas must be delineated, it appears that accurate soil maps, properly interpreted, will give a good estimate of areas subject to flooding.
Variability of rainfall affecting runoff from a semiarid rangeland watershed
Authors: Osborn H. B. , Hickok R. B.
Published: February 2008

On the 58‐square‐mile Walnut Gulch watershed in southeastern Arizona, summer precipitation is characterized by intense thunderstorms of limited areal extent; winter precipitation, usually rain, is characterized by low‐intensity storms of wide areal extent. For 11 years of record from 30 recording gages, about 70% of the annual precipitation of 11.22 inches occurred in the summer months June through September. Summer precipitation exceeded winter precipitation in each of the 11 years of record. Average annual precipitation varied from 7.1 to 14.2 inches for the period of record. During the same period, point precipitation varied from slightly under 5 inches to slightly over 20 inches. The lowest annual point precipitation was about 50 to 60% of the highest. Significantly more summer rainfall was recorded on the highest elevations than on the lowest, which indicated an effect of elevation on precipitation. However, the most summer rainfall, for the 11‐year period of record, was recorded near the center of the watershed, which indicated possible topographic influences other than watershed elevation. Annual runoff from Walnut Gulch varied from 0.02 inch (1 acre‐foot per square mile) to 1 inch (53 acre‐feet per square mile). For the same period on a 1‐square‐mile subwatershed, annual runoff varied from 0.02 inch (1 acre‐foot per square mile) to about 6 inches (320 acre‐feet per square miles).
Note on the standard error of the coefficient of skewness
Authors: Matalas Nicholas C. , Benson Manuel A.
Published: February 2008

Based on Slade's work in 1936, it has long been considered that a skew coefficient is not reliable if it is computed from a sample of less than 140 items. This limitation is erroneous and has acted as a deterrent to the use of computed frequency distributions. A table of the standard error of the skew coefficient is presented to assess the value of a skew coefficient from any sized sample.
On the paper entitled ‘Drawdown in a well of large diameter’ by I. S. Papadopulos and H. H. Cooper, Jr.
Authors: Narasimhan T. N.
Published: February 2008

The paper, ‘Drawdown in a Well of Large Diameter,’ as the authors themselves have pointed out [Papadopulos and Cooper, 1967], has been written with a view to help hydrogeologists in Asian countries, where ground water is developed to a large extent by means of large diameter open wells. The method suggested in the paper was applied by this writer to analyze drawdown data from a few large diameter wells piercing alluvial sands, and satisfactory results were obtained.

Specifically, the method proposed is valid for aquifers with relatively high transmissibilities or wells of relatively small diameters. That is, the method is most satisfactorily applied in those cases in which the quantity of water developed from storage in the open well is small compared with that developed from inflow into the well. It has been pointed out [Papadopulos and Cooper, 1967, p. 244], ‘Therefore, data that completely fall on the almost straight line part of the type curves cannot be analyzed by this method, or, in fact, by any other method.’
Two Weirs for Accurate Stream‐Gaging of Small Watersheds
Authors: Nutter Wade L. , Sopper William E.
Published: February 2008

Stage‐discharge relationships were determined for a sharp‐crested compound 30°–150° V‐notch weir and a sharp‐crested parabolic weir. Measurements were obtained from both laboratory models and field installations. Both weir designs were found to be more accurate and sensitive in detecting small changes in discharge at low flows than the conventional sharpcrested 90° and 120° V‐notch weirs.
On the Quantitative Inventory of the Riverscape
Authors: Leopold Luna B. , O'Brien Marchand Maura
Published: February 2008

In the vicinity of Berkeley, California, 24 minor valleys were described in terms of factors chosen to represent aspects of the river landscape. A total of 28 factors were evaluated at each site. Some were directly measurable, others were estimated, but each observation was assigned to one of five categories for that factor. Each factor for each site was then expressed as a uniqueness ratio, which depended on the number of sites being in the same category. The uniqueness ratio is believed to represent one way the scarcity of a given riverscape can be ranked quantitatively without bias based on notions of good or bad, and without assigning monetary value.
Miscible Displacement in an Unsaturated Glass Bead Medium
Authors: Krupp H. K. , Elrick D. E.
Published: February 2008

A series of miscible displacement experiments was conducted in an unsaturated glass bead medium maintained at a constant average water content during each displacement. The variation in the form of the breakthrough curve with decreasing water content was not large and was not related in a simple way to the water content; however, there was a consistent shift of the breakthrough curve to the left of the relative concentration value of 0.5 and 1 pore volume and a long tail or slow approach to the final relative concentration of 1.0. Some of these effects may be attributed to the presence of ‘stagnant’ liquid in the pores.
Comparing Attitudes toward Water Pollution in Syracuse
Authors: Frederickson H. George , Magnas Howard
Published: February 2008

A random sample survey of the attitudes of residents of Onondaga County, Syracuse, New York, toward water pollution and other local problems indicated the following: Water pollution is regarded as a middle‐level public priority, coming after education and law enforcement in the view of suburban residents and after education, law enforcement, housing, and employment in the view of city residents. Traffic, road maintenance, parks and recreation, and welfare were regarded by both city and suburban residents as lower‐order public priorities. The respondents felt directly affected by water pollution and associated it with various types of recreation. They regarded industry as a greater contributor to pollution than public jurisdictions and held local governments responsible for improving water quality. Respondents varied widely in their willingness to be taxed to abate pollution. Those with higher socioeconomic status were more willing to pay for pollution abatement than those with lower socioeconomic status.
Migration of Pollutants in a Glacial Outwash Environment
Authors: Crosby James W. , Johnstone Donald L. , Drake Charles H. , Fenton Robert L.
Published: February 2008

A test drilling program was conducted in a drain field area of the Spokane Valley, Washington, to study the movement of pollutants in glacial outwash deposits when they are subjected to extreme pollutant loads. Contrary to what might be expected, very dry soils were found at depth beneath the drain field, and it is concluded that most of the waters are being dispersed laterally by capillary mechanisms. Much of the systemic water may ultimately be returned to the atmosphere by evapotranspiration. Moisture conditions in the drain field system strongly indicate that ground‐water recharge through incident precipitation in this part of the Valley would be highly improbable. Chemical pollutants are found to travel with moisture fronts, but fine materials are determined to be very effective in filtering bacteria within a relatively few feet of the leach bed.
Streamflow Increases Following Farm Abandonment on Eastern New York Watershed
Authors: Black Peter E.
Published: February 2008

Analyses of long‐term precipitation, temperature, and runoff records indicate that runoff from a 180‐square‐mile watershed in New York State is undergoing a slow but steady change. Although potential evapotranspiration has remained constant, percentages of precipitation appearing as runoff, dormant season runoff, and total runoff have all increased as abandoned farm land passes through a brush and scrub forest stage before reverting to the mature forest. (Key words: Forest; land use; runoff)
The Use of Oxygen 18 and Deuterium Concentrations in the Water Balance of Lakes
Authors: Dinçer T.
Published: February 2008

Natural concentrations of stable isotopes of hydrogen and oxygen are used to determine the water balance of lakes situated in a subhumid climate in southwestern Turkey. A salt lake in that region is used as an index to the molecular exchange process between the lake and the atmospheric moisture. Such use of stable isotopes of oxygen and hydrogen in water balance studies appears to yield promising results and indicates that environmental isotopic studies might be a useful tool in limnological studies. (Key words: Environmental isotopes; molecular exchange; lake water balance)
Synthetic Hydrographs: Effects of Network Geometry
Authors: Surkan A. J.
Published: February 2008

A mathematical model for channel networks represented by directed graphs on a rectangular grid is used to generate synthetic hydrographs. This makes possible simulation of the effects of changes in geometric factors specified by shape and connectivity, while keeping fixed a prescribed temporal and spatial precipitation pattern. Alternatively, this model may be used with fixed networks of interest to study effects of different types and motions of storms. The model provides for a discrete approximation of a distributed network, a transformation relating the runoff hydrograph and input precipitation. No combinations of generating parameters had to be determined, since only a single parameter associated with the collection and release of water to the channel was used. Although this parameter, which was the collection area storage constant, and the speed of travel for precipitation could be given different values at each point on the network, and might be varied as a function of time, both were assumed to be fixed in time and spatially uniform. The formation of hydrographs is determined by interlocking relationships between the network's geometry, its storage functions, and temporal and spatial variations of precipitation reaching and traversing a graphically specified network.
The Mechanism of Natural Ground‐Water Recharge and Discharge: 1. One‐dimensional, Vertical, Unsteady, Unsaturated Flow above a Recharging or Discharging Ground‐Water Flow System
Authors: Freeze R. Allan
Published: February 2008

The unsaturated flow processes of infiltration and evaporation are in physical and mathematical continuity with the parallel saturated processes of recharge and discharge. Water table fluctuations result when the rate of ground‐water recharge or discharge is not matched by the unsaturated flow rate created by infiltration or evaporation. A water‐table rise provides the source of replenishment to the ground‐water zone that allows the prevailing rate of recharge to continue. This dynamic water‐table behavior can be simulated by a one‐dimensional, numerical mathematical model involving transient flow through an integrated saturated‐unsaturated system. The solutions are applicable to homogeneous, isotropic soils in which the functional relationships show hysteresis properties. The model allows upper boundary conditions of constant rate rainfall, ponded water, evaporation, and redistribution. It can be used to determine the water‐table fluctuation that will arise from a given set of initial conditions, boundary conditions, and soil type. The effects of variations in the parameters that control the flow are examined to arrive at a better understanding of the mechanism of natural ground‐water recharge and discharge.
Identification of Nonlinear Parameters of Ground Water Basins by Hybrid Computation
Authors: Vemuri Venkateswararao , Karplus Walter J.
Published: February 2008

Identification of parameters of an unconfined aquifer in which the dynamics of the water table are describable by a partial differential equation can be looked upon as a control system problem in distributed parameter systems. Using a maximum principle in conjunction with a steepest descent algorithm, the transmissibility of an aquifer is identified, starting from observed values of input‐output as data. This algorithmic procedure is blended with a heuristic method to identify the storage coefficient and the boundary of an aquifer. Results of computations carried out on a hybrid computer are presented.
Computer Experiments With Fractional Gaussian Noises: Part 1, Averages and Variances
Authors: Mandelbrot Benoit B. , Wallis James R.
Published: February 2008

Fractional Gaussian noises are a family of random processes such that the interdependence between values of the process at instants of time very distant from each other is small but nonnegligible. It has been shown by mathematical analysis that such interdependence has precisely the intensity required for a good mathematical model of long run hydrological and geophysical records. This analysis will now be illustrated, extended, and made practically usable, with the help of computer simulations. In this Part, we shall stress the shape of the sample functions and the relations between past and future averages.
Precipitation‐runoff relations for very small semiarid rangeland watersheds
Authors: Osborn H. B. , Lane L.
Published: February 2008

Simple linear regression models for predicting total volume of runoff, peak rate of runoff, duration of runoff, and hydrograph lag‐time were developed using three years of data from four small (0.56 to 11.0 acres) watersheds. The models developed indicated that runoff volume was most strongly correlated to total precipitation; that peak rate of runoff was most strongly correlated to the maximum 15‐minute depth of precipitation; that flow duration was most strongly correlated to watershed length; and that lag time was most strongly correlated to watershed area. These independent variables accounted for 70, 70, 50, and 30%, respectively, of the variance in the predicted variables. The exponential decay form of the antecedent precipitation equation accounted for 8% of the variation in runoff on one watershed but was insignificant on the others. Analysis indicates that the data represent the high frequency events. It is possible that these models will not accurately predict the low frequency events.
Perception and Public Policy in the Recreational Use of Domestic Water Supply Reservoirs
Authors: Bauman Duane D.
Published: February 2008

Recreational activities are more restricted on domestic water supply reservoirs in the Northeast and Far West than in the remainder of the United States. In the Northeast and Far West, recreational activities are usually prohibited from domestic water supply reservoirs, especially bodily contact activities; the water managers view recreation as incompatible with the production of safe potable water, and consumer opinion opposes such reservoir use. In the remainder of the country, recreational activities are not only allowed on domestic water supply reservoirs, but the water managers do not consider reservoir recreation as inimical to the hygienic and aesthetic qualities of the drinking water, and the public favors such reservoir use. From a literature review, the writer concludes that all recreational activities can be permitted on domestic water supply reservoirs without any measurable increase in the risk of water‐borne disease if the water is properly treated.
Linear programing for hydrologic analyses
Authors: Deininger Rolf A.
Published: February 2008

The estimation of the parameters of hydrologic models often poses difficulties since nonnegativity requirements, inequalities, and other constraints limit the use of standard statistical analyses. The use of linear programing techniques to estimate the parameters based on the criteria of minimum absolute deviations and on minimum maximum deviations appears to be advantageous since well established algorithms and computer programs exist.
Effect of changes of streamflow regimen on reservoir yield
Authors: Hawkins Richard H.
Published: February 2008

A presumptive approach was used to gain insight into the question: How do alterations of streamflow characteristics affect downstream objectives? The special case of flows changed in timing and volume from management on the tributary watershed in tandem combination with a downstream reservoir was considered. Change in mean yield of the reservoir was taken as an index of utility of the streamflow changes. Uniform increases of streamflow of 5% and 15% and a half month delay in the annual hydrograph were assumed either singly or in combination, storage yield computations made, and differences in yields determined. Not all extra streamflow was found to be useful although the increases gained utility with increasing storage availability. A timing delay was most important with smaller storage availability and then only to a limited degree. Flow increases combined with a timing delay produced results that were approximately simple additions to the two individual effects.
Ecological effects of silver iodide and other weather modification agents: A review
Authors: Cooper Charles F. , Jolly William C.
Published: February 2008

The silver ion is among the most toxic of heavy metal ions, particularly to microorganisms and to fish. The ease with which Ag forms insoluble compounds, however, reduces its importance as an environmental contaminant. Ag is not likely to concentrate to harmful levels through either terrestrial or aquatic food chains. There is some possibility that Ag from cloud seeding will retard growth of algae, fungi, bacteria, and fish in fresh water; additional laboratory investigations are needed. Inhibition of aquatic microorganisms would interfere with the cycle that returns essential nutrients to the water. Ag in air and water should be regularly monitored. Iodine in AgI poses no environmental danger. Organic seeding agents currently being proposed are not likely to be toxic in either the short or the long run, but dispersal of proprietary organic compounds should be prohibited unless their composition is fully revealed.
The mechanism of natural ground‐water recharge and discharge: 2. Laboratory column experiments and field measurements
Authors: Freeze R. Allan , Banner James
Published: February 2008

A mathematical model has previously been used to simulate one‐dimensional, vertical, unsteady, unsaturated flow above a recharging ground‐water flow system. Results from this model are given further credence by their successful correlation with the results from a laboratory column experiment using a tensiometer‐transducer system. The process of ground‐water recharge involves the entry into the saturated zone of water made available at the water‐table surface, together with the associated flow away from the water table within the saturated zone. Ground‐water recharge rates are controlled by the regional ground‐water flow system. Infiltration to the water table through the unsaturated zone leads to water‐table rises that provide the source of replenishment which allow prevailing rates of ground‐water recharge to continue. On the Canadian prairies, cases of recharge‐sustaining infiltration to the water table are isolated in time and space. Only spring snowmelt, and on occasion heavy summer rains, are effective. A large percentage of the snowmelt, however, is made available at the surface prior to the thawing of the frost wedge and therefore does not infiltrate. Effective infiltration is depression focused, and certain portions of ground‐water recharge areas may never receive direct infiltration to the water table. Observation well hydrographs of water table fluctuations alone are not sufficient to monitor recharge phenomena; measurements of the hydraulic gradient above and below the water table are necessary. It is erroneous to map a sand or gravel plain as an effective recharge area without first investigating the influence of the unsaturated hydrologic properties of the soil.
Field and laboratory determination of the hydraulic diffusivity of a confining bed
Authors: Wolff Roger G.
Published: February 2008

The field and laboratory evaluations of the hydraulic diffusivity of a confining bed are presented. The field approach consisted of measuring the head in the confining layer by placing piezometers equipped with differential pressure transducers at different depths in the confining layer. Pumping from the overlying aquifer resulted in an observed head change at the aquifer confining bed interface which for long periods of time could be approximated by a step drawdown. The best fit of observed data to the set of theoretical type curves for the step drawdown solution yields a hydraulic diffusivity, K'/S'S, of 2.9 × 10−2 cm2/sec. Hydraulic diffusivity values for the natural effective load, as obtained in the laboratory using consolidation techniques, are in general agreement with this result. Hydraulic conductivity values as determined in the laboratory by consolidation and constant flow methods are generally similar for the same sample. Particle size distribution and the clay mineralogy are also given for each sample.
Spatial distribution of rainfall rates
Authors: Huff F. A.
Published: February 2008

A 29‐storm sample of 1‐minute rainfall rates was obtained with an Illinois network of 50 recording gages in 100 square miles during the warm seasons of 1952 and 1953. These gages were equipped with enlarged orifices and 6‐hour charts to provide nearly instantaneous spatial patterns of rainfall intensity on the network. The data were used to determine quantitative estimates of rainfall rate gradients, sampling errors in the measurement of mean areal rates, and spatial correlation patterns. The derived relations are considered first approximations for midwestern warm‐season storms. It was concluded that the spatial variability of rainfall rates is frequently so great within and between convective storms that the rain gaging equipment and operational requirements for accurate rate measurements may be prohibitive for most users when sampling areas are 100 square miles or greater. Consequently it is recommended that the use of radar in combination with recording gages be investigated as a possible solution to the measurement problem.
Urban storm runoff relations
Authors: Viessman Warren , Keating Walter R. , Srinivasa Kalkunte N.
Published: February 2008

A model incorporating the hydrologic and hydraulic phases of storm water flows to estimate the runoff from a 23‐acre residential area has prediction errors that are generally less than 10% when the peak flow is used as the criterion for comparison.
On optimization methods for branching multistage water resource systems
Authors: Burt Oscar R.
Published: February 2008

The recent paper by Meier and Beightler [1967] and subsequent discussions [Loucks, 1968; Meier and Beightler, 1968] are interesting contributions to optimization methods in water resources development and management. However, it occurred to me that the positions taken in the exchange between Loucks and Meier and Beightler seemed to rule out the use of linear programing (and nonlinear programing) jointly with dynamic programing within the same optimization scheme. Presentation of such models for application to branching multistage systems is the primary objective of this letter.

First it is noted that the class of problems considered by Meier and Beightler [1967] had the following properties: (1) additivity in the criterion function, (2) linearity in the constraints, and (3) essentially the so‐called angular form in the constraint equations [Dantzig, 1963, p. 466]. The first property is very common in dynamic programing models, but other forms of criterion functions meet Bellman's definition of the Markovian‐type process [Bellman, 1961, p. 54]. It is very likely that the additive type will suffice in most water resource applications; but if it does not, a dynamic programing formulation may contain so many state variables that it becomes infeasible as an empirical model. The Markovian requirement can usually be met by introduction of a sufficient number of state variables. The second property is a direct consequence of an assumed linear transformation function for the state variable [Meier and Beightler, 1967, p. 648]. In problems such as water quality control, some of the transformation functions are apt to be nonlinear, but this causes no difficulty in dynamic programing. The third property is a direct consequence of the problem being amenable to a dynamic programing formulation.
An Application of Spatial Equilibrium Analysis to Water Resource Allocation
Authors: Flinn J. C. , Guise J. W. B.
Published: February 2008

An interregional equilibrium model of a type developed by Takayama and Judge is used as a basis to derive the optimal allocation and pricing of regulated supplies of water in a river basin. The model assumes that a river basin authority acts as the sole public utility distributor of water over time and that the capacity to supply water within any time period may be constrained by the physical structure of the system. The potential usefulness of such a model is demonstrated and the results discussed. Models of this type have considerable potential for empirical research in the field of water resources.
The 3‐Parameter Lognormal Distribution and Its Applications in Hydrology
Authors: Sangal B. P. , Biswas Asit K.
Published: February 2008

The 3‐parameter lognormal distribution is a general skew distribution in which the logarithm of any linear function of a given variable is normally distributed. The distribution is applied to the frequency analysis of floods, annual flows, and monthly flows, and a comparison with other commonly used methods suggests that it can be successfully used for this purpose. A procedure for its application has been suggested using only the median, the mean, and the standard deviation of the original data. The Gumbel distribution is a special case, and any straight line on the Gumbel probability paper can be transformed into a straight line on the lognormal probability paper by the 3‐parameter lognormal distribution. The sample of 10 stations used in this study all exhibited negative skewness for the logarithms of the data and therefore the lognormal distribution that assumes this skewness equal to zero has generally given high estimates.
Observations on the Growth of Needle Ice
Authors: Soons Jane M. , Greenland David E.
Published: February 2008

Observations of needle ice were made in the field and in the laboratory. In both situations multitiered needles formed during a single freeze‐thaw cycle. Four freeze‐thaw cycles were induced in the laboratory. Ice needles grew during each cycle but became less abundant as the soil surface dried out. During the first cycle two‐tiered needles grew; in later cycles a layer of frozen soil developed under a single layer of needles. Measurements of soil heat flow, changes of soil moisture, and loss of moisture by evaporation allowed calculations of the heat balance of the surface to be made. These measurements demonstrate the importance of heat released in the conversion of water into ice. Comparison of field and laboratory results shows a contrast in the mechanism of heat loss in the two situations (radiative as opposed to evaporative), but this contrast is unimportant in the formation of ice needles. Water availability appears to be a more important control of ice needle growth. Development of multitiered ice needles is not dependent on the number of freeze‐thaw cycles but may result from a critical balance between the soil cooling rate, the amount of available moisture, and the release of heat by conversion of water into ice.
Numerical Solution of the Boussinesq Equation for Aquifer‐Stream Interaction
Authors: Hornberger George M. , Ebert Janet , Remson Irwin
Published: February 2008

An efficient numerical technique is used to obtain solutions of the Boussinesq equation for problems of groundwater recession and groundwater flow in response to changes in stream stage. Comparison of the numerical results with the analytical solution of Boussinesq [1904] attests to the accuracy of the former. The solution of a recession problem indicates that the form of the Werner and Sundquist [1951] model of groundwater discharge recession is appropriate. The solution of a problem involving changing boundary conditions on an aquifer because of a flood wave provides data relative to groundwater outflow. A comparison with the results of Cooper and Rorabaugh [1963] evaluates the applicability of a linear model of unconfined flow.
Moire Pattern Techniques in Groundwater Hydrology
Authors: Freeze R. Allan
Published: February 2008

The moire pattern technique provides a conceptual or teaching tool that can be applied to problems involving the superposition of potential field solutions. Moire interference also forms the basis of a measurement technique that can be adapted for use with the membrane analogy for groundwater flow.
BOD Mass Balance and Water Quality Standards
Authors: Whipple William
Published: February 2008

To establish appropriate water quality controls, the magnitude of the gross pollution load of a basin should be known. Usually it is not. Mathematical modeling of basinwide BOD relationships can be greatly facilitated by applying known equations on a basis of BOD mass loading rather than of BOD concentration. The necessary hydrologic basis includes travel time dye tests, data as to slopes and distances, and computation of travel times for all parts of the basin at various stages. Treatment plant and instream BOD records are essential. The basic BOD removal parameter must be computed and adjusted for different conditions. The remaining computations require a computer but are not especially difficult. The principal reservation as to accuracy of the results consists of the allowance that must be made for nitrogenous BOD. Applications of this method to three New Jersey basins indicate that in each case the recorded BOD data from treatment plants account for less than half of the total pollution loading entering the stream. The policy implication is that it is inappropriate to plan water quality standards and programs of corrective measures on the assumption that recorded effluents constitute the only major source of pollution.
A Numerical Technique for Calculating the Transient Position of the Saltwater Front
Authors: Pinder George F. , Cooper Hilton H.
Published: February 2008

The movement of the saltwater front in coastal aquifers, including the effect of dispersion, can be determined by using numerical methods. The method of characteristics is used to solve the solute transport equation, and the alternating direction iterative procedure is used to solve the groundwater flow equation for the two‐dimensional problem. This approach permits the treatment of transient flow in nonhomogeneous aquifers with irregular geometry.