bluuebunny/crossref_metadata_2025 huggingface dataset:
The Interindustry Water Content Matrix: Applications on a Multiregional Basis
Authors: Lofting Everard M. , Davis H. Craig
Published: February 2008

An interindustry or input‐output model represents the structural interdependence of a national or regional economy. The inverse matrix of such a model reveals in each entry the amount of a given commodity necessary for the delivery of a unit of output of product to final demand. Usually, such entries are in dollar terms; however, these values can be converted to factor requirements such as man‐years of labor or acre‐feet of water. Such matrices are then termed ‘factor content’ matrices. Some of the specific uses of a ‘water content’ matrix constructed from a western states multiregional input‐ouput model and a vector of water use coefficients are discussed. Suggestions are made concerning improvement of the present water use data and the applicability of these data to regional water planning.
Ground‐Water Flow Related to Streamflow and Water Quality
Authors: Van Voast W. A. , Novitzki R. P.
Published: February 2008

A ground‐water flow system in southwestern Minnesota illustrates water movement between geologic units and between the land surface and the subsurface. The flow patterns indicate numerous zones of ground‐water recharge and discharge controlled by topography, varying thicknesses of geologic units, variation in permeabilities, and the configuration of the basement rock surface. Variations in streamflow along a reach of the Yellow Medicine River agree with the subsurface flow system. Increases and decreases in runoff per square mile correspond, apparently, to ground‐water discharge and recharge zones. Ground‐water quality variations between calcium sulfate waters typical of the Quaternary drift and sodium chloride waters typical of the Cretaceous rocks are caused by mixing of the two water types. The zones of mixing are in agreement with ground‐water flow patterns along the hydrologic section.
Noah, Joseph, and Operational Hydrology
Authors: Mandelbrot Benoit B. , Wallis James R.
Published: February 2008

By ‘Noah Effect’ we designate the observation that extreme precipitation can be very extreme indeed, and by ‘Joseph Effect’ the finding that a long period of unusual (high or low) precipitation can be extremely long. Current models of statistical hydrology cannot account for either effect and must be superseded. As a replacement, ‘self‐similar’ models appear very promising. They account particularly well for the remarkable empirical observations of Harold Edwin Hurst. The present paper introduces and summarizes a series of investigations on self‐similar operational hydrology.
A Least‐Squares Hydrograph Analysis of Complex Storms on Small Agricultural Watersheds
Authors: Overton D. E.
Published: February 2008

The feasibility of a least‐squares technique developed by Snyder [1955] for extracting unit hydrographs from complex storms was investigated for application to small agricultural watersheds. The procedure is the reverse of hydrograph synthesis. Rather than summing unit hydrographs to synthesize a complex storm, the unit hydrograph was calculated. When summed, the unit hydrograph produced the best fit to the storm hydrograph. The feasibility of the technique was clearly shown on four of the five ARS watersheds in the study. Large perturbations occurred in the calculated unit hydrographs on one of the watersheds, but sensible results were obtained on the remaining four. The calculated unit hydrographs varied from storm to storm as expected. The results of these analyses demonstrate the feasibility of the least‐squares technique as a means of analyzing all storm hydrographs on small agricultural watersheds to detect the nonlinearity of the rainfall‐runoff process.
The Response of Water Temperatures to Meteorological Conditions
Authors: Edinger John E. , Duttweiler David W. , Geyer John C.
Published: February 2008

The exchange of heat across the air‐water interface is one of the more important factors that govern the temperature of a water body. The net rate of heat exchange at the water surface is the sum of the rates at which heat is transferred by radiative processes, by evaporation, and by conduction between water and overlying air. The net rate can be evaluated in terms of a thermal exchange coefficient and an equilibrium temperature, both of which depend on observable meteorological variables. Any one of the many evaporation formulas and mathematical descriptions of the other heat exchange processes may be used to develop equations involving the thermal exchange coefficient and equilibrium temperature. Such equations are useful in developing relations that describe the temporal and spatial temperature distributions within a water body. They provide additional insight into the effects of meteorological conditions on water temperatures, and they facilitate estimates of various terms of the heat budget.
Estimating Probabilities of Research Success in the Atmospheric Sciences: Results of a Pilot Investigation
Authors: Julian Paul R. , Kates Robert W. , Sewell W. R. Derrick
Published: February 2008

In this paper we have two main objectives. The first of these is to outline a research and payoff (R&P) model that suggests a procedure for evaluating competing or concurrent research projects. The atmospheric sciences provide a good example for an initial application of the model. Weather modification, particularly artificial stimulation of precipitation, has been touted as an answer to many water resource problems. Alternatives to this technology have received little attention. We suggest that the R&P model could profitably be applied in this instance. The second objective of the paper is incorporated in a pilot study of the first step in such an application: namely, the determination of the estimated probabilities of success of various technologies in the atmospheric sciences. For this step, responses to a questionnaire sent to professional atmospheric scientists were examined to determine whether (a) scientists are willing to provide probability estimates of success of various technologies and whether these estimates are consistent with other estimates of success; (b) personal involvement in a field influences such estimates; (c) the probability estimates are consistent with the respondents' assignment of shares of a research budget; and (d) the estimates are generally in agreement with the reports of ‘blue‐ribbon’ panels of experts. We conclude that it is possible to obtain reasonably consistent estimates of research success from those who know most about them. The degree of optimism among those sampled is high, and it is highest for those workers involved in and having a high degree of knowledge of a particular field. Continued efforts in the determination of research success probabilities specifically tailored to the R&P model are recommended.
Frequency Curves for Annual Flood Series with Some Zero Events or Incomplete Data
Authors: Jennings M. E. , Benson M. A.
Published: February 2008

In fitting a theoretical frequency distribution to a set of data, a problem arises if the series contains a number of zero values, as may occur in annual flood peak data for small, arid‐region streams. The problem is twofold: first, commonly used distributions do not fit such a set of data; second, if a logarithmic transformation of the data is being used, logarithms of zero flows are not usable in a computation. To overcome the difficulties, a theorem of conditional probability is used. The probability of occurrence of a nonzero peak is combined with the conditional probability of exceeding a given flood magnitude, given that a nonzero peak has occurred. The method has been found useful also for fitting flood series in which information of peak annual floods below a specific stage is lacking.
Effect of small surface waves on evaporation through monolayers
Authors: Dick G. F. , Marchello J. M.
Published: February 2008

The role played by capillary‐gravity waves on evaporation through monolayers was studied for waves in the 400 to 800 cpm range. Waves were generated in a small ripple tank during steady‐state evaporation. Concentrations of n‐hexadecanol ranging from. 0 to 26.56 × 10−10 moles/cm2 were studied. The waves destroyed much of the evaporation‐retarding properties of the film.
Relation of water loss to moisture content of hydrophytes in a natural pond
Authors: Eisenlohr W. S.
Published: February 2008

Hydrophytes growing in natural ponds on the Coteau du Missouri in North Dakota have been studied. Previous studies in the same region showed how transpiration by hydrophytes could be separated from the total water loss from a natural pond, during the period that vegetation was growing in height, on the basis of a correlation between the height of vegetation and a mass‐transfer coefficient. It is shown that a similar separation can be made during the period of declining activity of the vegetation. A significant correlation was found between the ratio of moisture content of vegetation to its oven‐dry weight and the mass‐transfer coefficient. Weekly photographs on Ektachrome Infrared Aero film helped to confirm some of the phenomena observed.
Theoretical Stream Lengths and Drainage Areas in Horton Nets of Various Orders
Authors: Liao K. H. , Scheidegger A. E.
Published: February 2008

The paper presents tables of calculations of the expected stream lengths and drainage areas of Strahler streams of various orders for networks with various numbers of first order streams, based on the random‐graph model of such networks.
Influence of Pinyon‐Juniper Conversions and Water Quality on Permeability of Surface Soils
Authors: Gifford Gerald F. , Tew Ronald K.
Published: February 2008

Chaining with windrowing treatment in the pinyon‐juniper vegetation type significantly increased permeability of surface soils from the 0–2 and 2–4 inch depths at a site in southwestern Utah. Double chaining with debris in place did not yield a significant increase in permeability. Permeability of surface soils from a pinyon‐juniper site in south‐eastern Utah provided a similar trend, though significant differences among treatments were not evident. Water quality influenced percolation only after approximately 30 minutes. Multiple regression equations developed for predicting intrinsic permeabilities varied according to water quality.
Continuous hydrograph synthesis with an API‐type hydrologic model
Authors: Sittner Walter T. , Schauss Charles E. , Monro John C.
Published: February 2008

The U. S. ESSA Weather Bureau Hydrologic Research and Development laboratory has developed a complete hydrologie model utilizing an antecedent precipitation index (API) type rainfall‐runoff relation to compute surface runoff. With increasing demand for continuous river forecasts as well as flood forecasts, it is necessary to have a model that will predict all components of flow as functions of observable independent parameters on a continuous basis. To formulate the model, existing and proved techniques were used where possible and new techniques developed as necessary. The model consists of four basic parts: a relation for computing ground‐water recession, a method of computing the ground‐water flow hydrograph as a function of the direct runoff hydrograph, an API‐type rainfall‐runoff relation, and a unit hydrograph. The rainfall‐runoff relation is of the incremental type, yielding a runoff computation for each 6‐hour period rather than computing the total storm runoff. This has been accomplished through the inclusion of a new parameter, retention index. Two important features of the model are the ease of adjusting parameters to observed flow and the sequential development of the four basic parts with a minimum of interaction.
Relative density effects on incipient bed movement
Authors: Ward Bruce D.
Published: February 2008

The Shields entrainment function, extrapolated from bed load movement to predict the threshold of particle motion, appears deficient in analyzing incipient shear data for fluid‐sediment combinations encompassing a wide range of relative densities. Equations describing incipient dynamic equilibrium, solved semiempirically, indicate additional density considerations that must be included in an attempt to correlate initial movement for all possible sedimentation density ratios. This and other experimental investigations also indicate any entrainment function to be dependent on the state of the bed and corresponding turbulence. Other factors which might be influential on the threshold of particle movement are mentioned.
Stochastic Aspects of Lake Ontario Evaporation
Authors: Yu Shaw L. , Brutsaert Wilfried
Published: February 2008

Time series analysis was carried out on long‐term monthly mean values of evaporation from Lake Ontario, which were generated in an earlier study, and on related meteorologic parameters. Correlation and spectral analyses showed that the annual cycle was dominant in all the time series. Evaporation is usually high in autumn and winter and low in spring and summer. A warming trend was observed in the air temperature and a drying trend in the relative humidity series. Except for the wind speed, no significant trend was found for the other time series. Cross correlation and cross‐spectral analyses showed a close relationship between evaporation anomalies and the anomalies of the other parameters. A first order Markov model adequately described the evaporation, air temperature, and relative humidity anomalies, whereas a second order model fitted the anomalies of wind speed and water surface temperature. Morton's [1967] water budget method yields higher evaporation estimates in the summer and lower estimates in the winter than the mass transfer estimates.
Accumulation of radionuclides in bed sediments of the Columbia River between the Hanford Reactors and McNary Dam
Authors: Nelson Jack L. , Haushild W. L.
Published: February 2008

Amounts of radionuclides from the Hanford reactors contained in bed sediments of the Columbia River were estimated by two methods: (1) from data on radionuclide concentration for the bed sediments between the reactors and McNary Dam, and (2) from data on radionuclide discharge for river stations at Pasco, Washington, and Umatilla, Oregon. Umatilla is 3.2 kilometers below McNary Dam. Accumulations of radionuclides in the Pasco to Umatilla reach estimated by the two methods agree within about 8%. In October 1965 approximately 16,000 curies of gamma emitting radionuclides were resident in bed sediments of the river between the Hanford reactors and McNary Dam. Concentrations and accumulations of chromium‐51, zinc‐65, cobalt‐60, manganese‐54, and scandium‐46 generally are much higher near McNary Dam than they are in the vicinity of the reactors. These changes are caused by an increase downstream from the reactors in the proportion of the bed sediment that is fine grained and the proportions of the transported zinc, cobalt, manganese, and scandium radionuclides associated with sediment particles.
A method of derivation of nonconstant watershed response functions
Authors: Snyder W. M. , Mills W. C. , Stephens J. C.
Published: February 2008

A practical numerical method has been developed for storm hydrograph analysis that allows variation of unit response functions during multiple periods of runoff producing rainfall. Previous methods of analytical derivation of unit responses from multiple period storms require superpositional linearity. This requirement is eliminated by substituting two stages of convolution for the conventional single stage process of storm hydrograph generation. The first stage convolves a fixed area‐characteristic function with a variable state function. The state function is determined by streamflow and differs for each increment of effective rainfall. First stage convolution thus produces a different unit response for each increment. The second stage convolves the variable unit responses and the effective rain increments. Validity of the technique is demonstrated by applying the analytical model to 10 complex storms. The conceptual components of area‐characteristic, area‐state, and variable response functions resulting from the analyses are seen to be hydrologically rational.
A Method to Analyze the Effects of Fluctuating Reservoir Water Levels on Shoreline Recreation Use
Authors: Jaakson Reiner
Published: February 2008

Fluctuations of numerous reservoirs have demonstrated that a direct relationship exists between water level and shoreline quality. An increasing acknowledgment that the recreation segment of many multipurpose projects forms one of the more active basic economic catalysts for regional growth has helped to justify the maintenance of constant, or near constant, levels during the recreation season. A methodology whereby the optimum water level for a reservoir can be identified, based on an analysis of recreation potential of the shoreline at different lake levels, presents an opportunity to quantify comparisons of variations in recreation quality. Applications of the methodology may also be made to assess shoreline damages due to flood levels. A shoreline inventory taken before a major flood may be compared to an inventory taken after the flood: differences in physiographic rates illustrate the loss of shoreline use due to erosion, to loss of tree cover, and to change of beach materials. Further uses of the methodology include economic comparisons of the value of maintaining constant lake levels with the value of maintaining flood storage levels. Dollar values attached to shoreline rates provide an estimate of the loss of shoreline use due to flood storage levels, which may be compared with the benefit of flood prevention in the floodplain of an adjoining river basin.
A Factor Analysis of Reservoir Losses
Authors: Knisel Walter G.
Published: February 2008

Analyses of loss rates from five floodwater detention reservoirs in cavernous terrain are presented. Thirteen variables were included in a factor analysis to determine those significant for estimating reservoir loss rates. Three variables were found to be significant for one reservoir, but the accuracy of estimate of loss rate was not significantly greater than for reservoir stage alone. Loss rates are related arithmetically and by power functions to reservoir stage. The amount of variance explained by reservoir stage ranges from 54% to 90%. Loss rates ranged up to 4.5 acre feet per hour for the five reservoirs.
Effect of Concentration Gradients on the Performance of a Nuclear Sediment Concentration Gage
Authors: McHenry J. R. , Coleman N. L. , Willis J. C. , Gill A. C. , Sansom O. W. , Carroll B. R.
Published: February 2008

A nuclear sediment concentration gage, using the attenuation of 22‐kev X rays from cadmium‐109 as a function of concentration, was evaluated in a series of laboratory tests conducted in a circulating water tunnel. Sediment concentration measurements were made with the X‐ray beam directed up, down, and across the test flume section. Coarse sand, fine sand, and kaolin were used as sediments in concentrations of 100 to 30,000 ppm. The suspensions were passed through the water tunnel at velocities of 0.7 to 3 meters sec−1. The response of the nuclear sediment concentration gage was not affected significantly by test position, type or size of particle, or velocity of sediment, but was a function of the total concentration of sediment in the test cross section.
Repayment Interest Rates for Water Projects
Authors: Hoggan Daniel H.
Published: February 2008

In the absence of a uniform federal interest rate policy for reimbursable costs of water projects, federal agencies generally have determined repayment interest rates administratively. For some specific projects, however, Congress has stipulated the interest rate to be used in the authorizing legislation. The rates used have varied among agencies and with different purposes of development. The repayment interest rate is of particular significance to the financial feasibility of proposed projects. An increase in this rate can substantially increase the cost of projects to local government or other entities responsible for repaying reimbursable costs. The current use of repayment interest rates lower than discount rates for project evaluaion also raises questions about the distribution of benefits. Although the U.S. Water Resources Council recently increased the evaluation interest rate and initiated studies of water project evaluation procedures in general, relatively little attention has been given to achieving a consistent policy for repayment interest rates and other aspects of cost allocation and cost sharing. This situation needs to be changed; these important aspects of water project development should not be neglected.
A Two‐Step Probabilistic Model of Storage Reservoir with Correlated Inputs
Authors: Klemeš V.
Published: February 2008

Fragmentation of Moran's model and decomposition of its transition matrix into a release rule and an input component are used to simplify the problem formulation for reservoirs with complex operating rules and to derive the Lloyd model directly from that of Moran by introducing two successive transitions of one variable instead of a single bivariate transition. Combined with Gould's concept of transition probabilities, the suggested model is used to take into account the correlation between monthly flows simultaneously with that between annual flows.
Effects of Forest Clear‐Felling on the Storm Hydrograph
Authors: Hewlett John D. , Helvey J. D.
Published: February 2008

Earlier speculation that evapotranspiration from forests and the consequent soil water deficits under forests are factors in the production of floodwaters was verified by a paired watershed experiment. Mature hardwood forest on a 108‐acre catchment in the southern Appalachians was clear‐felled after an 18‐year calibration period. No forest material was removed, and no overland flow (surface runoff) occurred. A statistical analysis of all major storm hydrographs before (77) and after (30) clearing revealed that after felling stormflow volume (quick flow) was significantly (0.001 level) increased 11% overall, or 0.23 inch at the mean quick flow volume of 2.1 inches. Peak discharge increased slightly after felling (about 6 cfsm or 7% at the mean peak flow of 92 cfsm), but the test was not as conclusive as in the case of quick flow volumes. Time to peak (time of rise), recession time, and quick flow duration were tested to an accuracy within 10% of their respective mean values (0.05 level), but no treatment effect was detected. Quick flow increases due to felling ranged from 0 in small floods to 1.9 inches during a record 7‐day flood sequence. The latter value represented a 22% increase over the total quick flow (8.7 inches) expected during that regional record flood. The effect of forest evapotranspiration on floodwater released by deep‐soil slopes persists throughout the year, a result explainable by the variable source area concept of runoff.
Groundwater Discharge in the Illinois Basin as Suggested by Temperature Anomalies
Authors: Cartwright Keros
Published: February 2008

Areas where ground water in the Illinois basin is moving vertically should be reflected by temperature anomalies. To test this hypothesis, an isothermal map for a depth of 500 feet was constructed, based on bottom hole temperatures of deep wells. This map was compared with a theoretical isothermal map for a depth of 500 feet that was made by projecting temperature gradients (calculated from the thermal conductivities of the rock) downward from the surface where mean annual air temperatures were known. The residual temperature map that was made on the basis of this comparison (calculated minus observed temperature) shows several warm and cool anomalies that are postulated to be discharge and recharge areas, respectively. Analysis of the curvature of the earth's thermal profile calculated for the basin suggests that approximately 59,000 acre‐feet of ground water per year are discharged upward from the deep rocks in the Illinois basin. This figure is of the same magnitude as an estimated excessive groundwater discharge into the region's streams of 43,000 acre‐feet, based on comparison of unit‐area discharge of streams in the basin with streams in similar areas outside the basin. From a simplified model of the basin, a groundwater inflow of about 36,500 acre‐feet from the surrounding highlands is estimated. A significant portion of this discharge must be through fracture zones associated with faults and anticlines in the basin, inasmuch as this amount of flow would require that the shales have a vertical permeability from one to three orders of magnitude higher than is generally observed. One such discharge area in southwestern Illinois is suggested by field data.
A Numerical Solution for Finite Amplitude Free Surface Waves
Authors: Fangmeier D. D.
Published: February 2008

A technique for the numerical solution of two‐dimensional potential flow with a free surface and gravity is presented. Its validity is demonstrated by application to wave generation by a pressure on a segment of the free surface of a ponded fluid. Wave profiles are obtained for the leading waves of progressive approximately periodic wave formations that show the effect of retaining the nonlinear terms in the free surface boundary conditions. The programing is relatively simple and the technique applicable to other wave forming situations. However, long computation times are required.
Theoretical Estimates versus Forest Water Yield
Authors: Lee R.
Published: February 2008

Theoretical and empirical models used to estimate the long‐term water balance of small catchments are inadequate as a check on the observed water balance. Under rigorous research conditions, the observational data are accurate to about ± 13–30% of yield, while the models are accurate only to about ± 10–60% of yield. Analysis of watershed data shows that the uncertainty in any comparison of theoretical and observed values usually is much greater than the difference between the values compared. In general, such comparisons are not helpful either in confirming or challenging the accuracy of water balance measurements, or in assessing the watertightness of catchment areas.
Effect of Dispersion, Gravitational Segregation, and Formation Stratification on the Recovery of Freshwater Stored in Saline Aquifers
Authors: Kumar Anil , Kimbler Oscar K.
Published: February 2008

A calculation procedure has been devised, using existing analytical and empirical relationships, to predict mixing and gravitational segregation in a horizontal radial flow system. The procedure yields results that show excellent agreement with experimental results obtained with a three‐dimensional laboratory flow model in which both mixing and gravitational segregation occur simultaneously. Thus validated, the calculation procedure was applied to the prediction of the efficiency with which freshwater stored in saline aquifers might be recovered for later use. Low aquifer water salinity, low formation permeability, and low formation thickness lead to the most favorable recoveries. The calculation procedure indicates that recovery efficiency improves with the number of injection‐production cycles, thus suggesting that even for unfavorable conditions the process might become feasible on a long‐term basis. Graphical presentations show the relative importance of several pertinent variables including formation stratification.
Estimation of Basin Precipitation by Regression Equation
Authors: McCulloch J. A. W. , Booth M.
Published: February 2008

Regressions on 30 years' precipitation data from five stations for the calculation of the monthly amount of precipitation falling on the land portion of the Lake Ontario basin are presented. Verification on three years' test data shows a maximum cumulative annual error of 4%, with individual monthly errors as high as 17%. Provision for missing data is made.
Trace Element Removal from Sewage Effluent by Soil Filtration
Authors: Lehman G. S. , Wilson L. G.
Published: February 2008

The concentrations of iron, manganese, nickel, copper, zinc, lead, and cadmium in a domestic sewage effluent were effectively reduced during percolation through about 8 feet of calcareous soil material contained in lysimeters. Strontium concentrations were not reduced by similar filtration. Cobalt and hexavalent chromium were not present in the effluent in quantities detectable by atomic absorption spectrophotometry. In a field study conducted on large plots over a three year period, larger quantities of iron, manganese, and copper in the filtrate indicate the possible saturation of the soil with several trace metals in a relatively short period of time.
Costs for Equivalent Upstream Reduction in Waste Water Discharges
Authors: Heaney James P. , Carter Buford J. , Pyatt Edwin E.
Published: February 2008

Regional water quality management models for river systems with multiple sources of pollution are reviewed. The optimal solution is analyzed from the point of view of comparing the efficacy of more intensive waste treatment by the individual waste discharger with the efficacy of increased upstream treatment. The value of upstream waste treatment to the individual discharger diminishes the further upstream one moves. A relationship for evaluating this trade off is presented. The alternative situations that might occur in a regional system are then analyzed. An application of the analysis to a hypothetical region is presented.
Convergence Criteria for Iterative Hydrologic Routing Models
Authors: Young G. K.
Published: February 2008

An iterative process that is used to solve flow dynamics is studied; a highway culvert and embankment system serves as an example. Time step criteria governing convergence of the iterative process is analyzed. The Lipschitz ratio is applied to calculate the controlling algebraic time step relationship. The time step for convergence is shown to vary with current inflow and antecedent storage. Parameters of the iterative process are calculated for the example by assuming nonlinear functional forms for stage storage and discharge storage relationships and by inferring the appropriate coefficients. Numerical results are presented for several extreme cases that bracket orifice and weir flow conditions. The approach should be applicable to other hydrologic systems such as small dams, catch basin flow, and retarding basins. As for the route or convolute question, which concerns the direct conversion of rainfall excess to watershed outflow, this analysis aids in the selection of a time increment for direct routing.
Variability of Annual Runoff in the Lake Ontario Basin
Authors: Sanderson Marie
Published: February 2008

A study of variability of runoff in the Lake Ontario basin is undertaken to provide background information for the International Field Year on the Great Lakes to be held in 1972 on Lake Ontario, since it is realized that a period of 1 year is a small sample in the life history of a lake basin and that there are large annual fluctuations in the variables in the water balance. Because of a lack of long‐term records of measured runoff, the Thornthwaite‐Mather water balance model for estimating point runoff from climatic data is used for the 81 stations in and near the basin with records of 15–136 years.

Statistical tests show that annual station runoff has a normal distribution, and standard deviations are computed to express variability. Maps of average runoff, as well as plus and minus two standard deviations of runoff, are drawn and thus permit the estimation of the volumes of annual runoff that can be expected in the Lake Ontario basin. A coefficient of variability of runoff map indicates that the southwestern areas of the basin have the most variable runoff.
Designing Reservoirs with Short Streamflow Records
Authors: Tschannerl Gerhard
Published: February 2008

A hydraulic structure such as a reservoir built on the basis of sample information is, in general, overdesigned or underdesigned in relation to perfect information. The resulting loss in net benefits is called the expected opportunity loss (EOL) due to imperfect information and is a function of sample size. Computation of the EOL requires perfect information. The EOL can, however, be found in one of two ways. One procedure estimates the EOL by sampling from a synthetic sequence of a stochastic input, such as streamflow, generated on the basis of estimates of the population moments. The other procedure involves a design decision within the framework of subjectivist (or Bayesian) statistics.
Hydrologic Response of a Young Pine Plantation to Weed Removal
Authors: Lambert J. L. , Gardner W. R. , Boyle J. R.
Published: February 2008

In May 1969 the weed vegetation on one plot in a 7‐year‐old red pine (Pinus resinosa, Ait.) plantation was killed by using herbicides. The site was a glacial outwash plain in Adams County, Wisconsin. Of the 27 cm of precipitation that occurred in June, July, and August of that year, evapotranspiration accounted for 16 cm on a plot with weeds and only 9 cm on the plot without weeds. But nearly all of this excess was lost from the root zone by a 61% increase in drainage associated with weed removal, so the increase of water available to plants was not great. The increase was most obvious in the surface layer beneath the trees where it amounted to 28%. In the openings between trees, the surface layer was actually drier owing to greater surface heating caused by removal of weeds. Important factors that amplified the effects of treatment were the erratic precipitation regime and the sandy texture of the soil.
An Economical Device for Optically Detecting Snow Depth at Remote Stations
Authors: Dirmhirn Inge , Craw Charles
Published: February 2008

An instrument is described that automatically records remote snow depth. It consists of an optically monitored silicon cell ladder and an electronics panel with a diode pump to generate yes/no signals of 0 or 2 volts. This system with minor adaptions can be integrated into any telemetering system. Records for one snowmelt situation are presented.
Snowmelt delay by oversnow travel
Authors: Hogan A. W.
Published: February 2008

Oversnow vehicles compact the snowpack several inches as a result of their passage; drifting snow tends to refill these tracks to ambient level. This repeated travel and drifting result in storage of much greater water content in the snowmobile trails than in the adjacent undisturbed snowpack. A brief field study was initiated to determine the magnitude of the increase in water content and the time delay of snowmelt in an area frequently traveled by oversnow vehicles.

The area chosen for study was an abandoned farm with an elevation of 700–1100 feet msl near the confluence of the Schoharie and Mohawk valleys. The area is quite hilly, and the rather steep slopes face north or east. Average snowfall in this area is about 80 in./year. During the study year approximately 120 inches fell, and there was continuous total snow cover from December 4, 1970, until the first bare spots appeared on April 1, 1971. Snowmobile travel began with the first snow and continued through the winter, the last known passage occurring after the snowstorm of April 10. No accurate log of time or number of snow vehicle traverses was maintained; however, 25–50 passages per week would be a reasonable estimate of traffic over the most often used trail.
Important considerations in the process of designing a groundwater data collection program
Authors: Hickey John J.
Published: February 2008

Three important considerations in designing a groundwater data collection program are (1) a clear understanding of the activities needed to solve a general groundwater management problem, (2) an explicit classification scheme for the physical and water quality models of a groundwater system, and (3) an understanding of the concept of accuracy and its use in the design of a program. The first consideration is important for the formulation of a well‐stated groundwater problem. The second consideration is important for the communication between resource managers and hydrogeologists. The third consideration is important for the estimation of the effort to be expended in a collection program. A classification scheme for the physical and water quality models of a groundwater system is proposed. The scheme is based on three types of physical models: (1) aquifer, (2) water budget, and (3) hydrodynamic; on three types of water quality models: (1) energy and chemical mass characteristics, (2) energy and chemical mass balance, and (3) energy and chemical mass transport; and on three types of model representations applicable to each physical and water quality model: (1) descriptive, (2) empirical, and (3) mathematical.
Snow measurement predicament
Authors: Peck Eugene L.
Published: February 2008

Increased interest in snow and snowmelt runoff has resulted in the need for a better knowledge of snowfall and the water equivalent of snow cover. Present measuring methods have proven valuable for seasonal runoff prediction and other water management requirements in major snow areas. However, more accurate estimates of the actual snowfall and the average areal snow cover are required for detailed water budget and water use studies and for input for the conceptual forecasting models now being developed. The limitations of present measuring systems are analyzed, and guidelines for their usefulness as indices are presented. The basic problems involved in determining more representative values are discussed, and suggestions are given for methods to improve measurements.
Saltation of plastic balls in a ‘one‐dimensional’ flume
Authors: Gordon Richard , Carmichael Jack B. , Isackson Frank J.
Published: February 2008

A one‐dimensional flume was designed and used for the quantitative measurement of the parameters of saltation and underwater collision for plastic balls transported over an unrippled bed by flowing water. Computer simulation reveals that saltation is maintained by the roughness of the bed. A geometric probability argument based only on the grain size distribution is used to derive the distance that a particle travels before entrapment, which turns out to be approximately proportional to the radius, as it has been previously measured. In the appendix the phenomenological stochastic transport equation is rederived from the basic assumptions.
Sampling requirements for areal water equivalent estimates in forested subalpine watersheds
Authors: Leaf Charles F. , Kovner Jacob L.
Published: February 2008

Statistical analyses were made of the snow course measurements on a 714‐acre forested subalpine watershed in central Colorado where melt rarely occurs during the winter snow accumulation season. The following guidelines were developed for sampling mountain snowpacks on an areal basis: (1) sampling zones should be stratified by elevation, the sampling in each zone being proportional, and (2) sampling points should be widely spaced over each zone, two duplicate measurements at most being made at a location.
Drawdown in a finite circular aquifer with constant well discharge
Authors: Kuiper L. K.
Published: February 2008

An analytical solution, which was obtained previously by Muskat, is derived for the groundwater head in a confined, homogeneous, isotropic aquifer with a constant thickness and a circular impermeable boundary at radial distance a from a well penetrating the entire depth of the aquifer and discharging at a constant rate. The solution is compared with the Theis solution, which is valid for an aquifer of unlimited extent. The comparison shows that the two solutions agree very closely at radial distance r when Tt/Sa2 < 0.25 and r/a ≤ 0.1, where t denotes the time since the well discharge began, T and S are the transmissivity and storage coefficients of the aquifer, and a is the radial distance to the circular impermeable boundary. The two solutions agree poorly when Tt/Sa2 becomes larger than 1.0 or r/a ⋍ 1.0.
Dynamics of flood frequency
Authors: Eagleson P. S.
Published: February 2008

The probability mass function of peak streamflow from a given catchment is derived from the density functions for climatic and catchment variables by using the functional relationships provided by the kinematic wave method of hydrograph forecasting. The exceedance probability for a flood peak of given magnitude is then related to the annual exceedance recurrence interval of this flood. The resulting theoretical flood frequency relation shows a changing form with change in catchment and climate parameters and agrees well with observations from three Connecticut catchments. It provides a theoretical basis for estimating flood frequency in the absence of streamflow records and for extrapolating empirical estimates based on short records. Because of the explicit appearance of physically meaningful catchment parameters it also allows quantitative estimates of the effect on flood frequency of changes in average land use. The flood frequency relation for a given catchment is averaged across the population of catchments of given size to provide a theoretical regional flood frequency function that compares favorably with observations of mean annual floods on 44 Connecticut catchments.
Identification of parameters in unsteady open channel flows
Authors: Becker Leonard , Yeh William W‐G.
Published: February 2008

This paper introduces the influence coefficient algorithm, a simple, easily implemented, and rapidly convergent computational procedure for the solution of the parameter identification problem in unsteady open channel flow from field observations on stage hydrograph and velocity distribution at one or more points along the channel. (Identification is a mathematical process whereby the parameters embedded in a differential equation defining a system are determined from observations of system input and output.) The parameters specifically chosen for identification are the two ‘friction slope’ characteristics: the channel roughness coefficient and the exponent of the hydraulic radius in the empirical friction slope relation, a number usually assumed to be 4/3. These parameters are not physically measurable and have to be determined from the solutions of the mathematical model using concurrent input and output measurements. This new procedure is related to both quasilinearization and gradient methods. Additionally, an effective formulation of the algorithm is shown to depend on certain stability and convergence features related to the finite difference solutions of the governing flow equations but often ignored or glossed over.
Ultrasonic velocities of the dilatational and shear waves in frozen soils
Authors: Nakano Yoshisuke , Martin Randolph J. , Smith Martin
Published: February 2008

Ultrasonic velocities of the dilatational and shear waves in water‐saturated frozen soils were measured as a function of temperature by both pulse first arrival and critical angle methods. A strong correlation exists between the dilatational wave velocities and the unfrozen water content. The observed hysteresis in the velocities of silt and clay during a freeze‐thaw cycle is considered to be caused by hysteresis in the frozen water content. A general tendency for the shear wave velocity to decrease with ascending temperature exists, but the effect of temperature is not as pronounced as on the dilatational velocity. Calculations based on measured dilatational and shear velocities showed that the Poisson's ratios of sand are almost constant. However, the ratios of silt and clay decrease monotonically with ascending temperature.
Determination of the hydraulic diffusivity of a heterogeneous confining bed
Authors: Wolff Roger G. , Papadopulos Stavros S.
Published: February 2008

The hydraulic diffusivity of a confining bed exhibiting vertical heterogeneity was determined by field and laboratory tests. A thin sand aquifer was pumped, and head changes were observed in the aquifer and at three vertically separated piezometers in the overlying confining bed. A four‐layer digital model was used to analyze the field data. Hydraulic diffusivities for each layer were adjusted in the model until calculated head changes in all piezometers closely matched those observed in the field. Laboratory‐determined hydraulic diffusivities were several orders of magnitude smaller than the field‐determined values. Interfingering of layers within the confining bed is believed to have caused this difference. Additional studies are needed before a general conclusion can be reached on the value of laboratory determinations of hydraulic parameters for heterogeneous confining beds.
Data selection for environmental simulations—A water temperature example
Authors: Young G. K. , Tseng M. T. , Taylor R. S.
Published: February 2008

How should data be selected for use in costly environmental simulation models? For a particular problem, namely, thermal pollution, the question becomes, What combination of meteorologic conditions should be used to simulate the thermal stress on an estuary under natural or man‐made heat loadings? Practical and standard approaches are required to select study conditions to support the preparation of expert testimony. A method combining computer simulations with series approximations is proposed. Three important parameters, wind speed, solar radiation, and dew point temperature, that influence the diurnal water temperature variation are considered in using the proposed analysis. Over 15 years of daily records of summer conditions at the weather station at Miami, Florida, are used to demonstrate the methodology. A Taylor series approximation is used to fit simulated responses in order to relate the probability of all days to the average day for the period studied. The technique should provide a tool for incorporating probability analysis into the study of thermal pollution in receiving waters. As a coarse approximation this approach can also be used for direct prediction of ambient water temperatures, very slight computer costs being invoked. The approach is adaptable to other environmental simulations.
Finite element method for the hydrodynamic dispersion equation with mixed partial derivatives
Authors: Nalluswami M. , Longenbaugh R. A. , Sunada D. K.
Published: February 2008

A ‘functional’ is developed for the two‐dimensional hydrodynamic dispersion equation that has mixed partial derivatives. The dispersion coefficients are treated as second order symmetric tensors. The concentration of the dispersing tracer is assumed to be given by a linear polynomial. The functional is minimized, and the result is a set of simultaneous first order linear differential equations that can be solved by suitable numerical procedures.
Field determination of the hydraulic properties of leaky multiple aquifer systems
Authors: Neuman Shlomo P. , Witherspoon Paul A.
Published: February 2008

A new field method is proposed for determining the hydraulic properties of aquifers and aquitards in leaky systems. Conventional methods of analyzing leaky aquifers usually rely on drawdown data from the pumped aquifer alone. Such an approach is not sufficient to characterize a leaky system; our new method requires observation wells to be placed not only in the aquifer being pumped but also in the confining layers (aquitards) above and/or below. The ratio of the drawdown in the aquitard to that measured in the aquifer at the same time and the same radial distance from the pumping well can be used to evaluate the hydraulic properties of the aquitard. The new method is supported by theory and has been applied to the coastal groundwater basin of Oxnard, California. The field results are in good agreement with laboratory measurements.
On the time when the extreme flood occurs
Authors: Todorovic P. , Woolhiser D. A.
Published: February 2008

The time of occurrence T(t) of the largest momentary flood exceedance in some time interval (0, t] is a stochastic process. The one‐dimensional distribution function and the mathematical expectation of T(t) are determined for the case in which individual flood exceedances are independent, identically distributed random variables and the counting process for exceedances is a nonhomogeneous Poissonian process. Rather good agreement between observed and theoretical distributions for two rivers indicates that these assumptions are not extremely restrictive.