bluuebunny/crossref_metadata_2025 huggingface dataset:
A technique of generating a synthetic flow record to estimate the variability of dependable flows for a fixed reservoir capacity
Authors: Colston N. V. , Wiggert J. M.
Published: February 2008

The variability of dependable flows for fixed storage is an important parameter that should be incorporated into the economic analysis of a water resource storage project. Flow values representative of the James River were computed by a hydrologic model that uses data randomly generated from monthly precipitation distributions. Dependable flows from fixed storage were found to have large variance. Confidence limits were placed on the dependable flows illustrating the wide range of possible dependable flows for a specified reservoir size, and suggesting the desirability of expressing benefit‐cost ratios for water resource projects in terms of confidence limits.
Length of stream for an independent events model
Authors: Dacey Michael F.
Published: February 2008

An independent events model is formulated for stream length. The stream is composed of links, where the number of links has the geometric distribution and link lengths are independently and identically distributed as the gamma variate with shape parameter α. This model is similar in all essential respects to the topologically random stream structure formulated by Shreve [1967; 1969]. This paper extends his results and shows that for α = 2 the distribution of stream length obeys a probability law defined by the modified Bessel function. It is also shown that when the expected number of links in a stream is large, stream length is approximated by the exponential distribution.
Synthesis of Urban Rainfall
Authors: Raudkivi A. J. , Lawgun N.
Published: February 2008

A statistical analysis of rainfall records is used to develop a computer model for generation of a sequence of short period rainfalls. The time intervals between rainfalls are generated by sampling from a frequency distribution fitted to the historical data. The model also uses a first order Markov process in addition to random sampling from a frequency distribution, to obtain the rainfall durations. Rainfall depths are obtained by sampling from the joint distribution of rainfall depths and durations. Model parameters are based on the meterologic conditions of the Auckland area, and all statistical tests were performed at a 5% level of significance. The model produces comparable time intervals between storms and a linear correlation between rainfall depths and durations, but extreme values of rainfall depths and durations are absent from the generated data.
Economic Efficiency Implications of Federal‐Local Cost Sharing in Water Resource Development
Authors: Marshall Harold Emory
Published: February 2008

The Army Corps of Engineers, Bureau of Reclamation, and Soil Conservation Service share costs of water resource development with nonfederal groups. An efficiency problem results when cost sharing rules induce local groups to demand projects that, although efficient for the local community, are not most efficient for society. An examination of present cost sharing shows that there are inconsistencies in cost sharing rules and practices among agencies. Such inconsistencies induce local groups to select techniques of production and scales of development that are not socially efficient. Two general rules for eliminating these inefficiencies are (1) to share in the same proportion costs of all techniques used to provide a single purpose, and (2) to share costs for a single purpose in proportion to benefits received at the margin. Application of these rules would result in lower social expenditures and higher local expenditures for a given level of development, and local groups would not have such strong incentives to shop among agencies for the lowest local cost share.
An Energy Budget Study Above the Forest Canopy at Marmot Creek, Alberta, 1967
Authors: Storr D. , Tomlain J. , Cork H. F. , Munn R. E.
Published: February 2008

For a 19‐day period in July 1967, daily estimates of evapotranspiration were obtained from hourly calculations of the Bowen ratio above the forest canopy. The estimates ranged from 7.9 mm to 1.5 mm. The Bowen ratio was found to be very dependent on wind direction, sky condition, and basin aspect, which was a significant factor. Although the area is unhomogeneous, the results appear reasonable when compared with other estimates of evapotranspiration.
Energy Relationships in the Design of Floating Covers for Evaporation Reduction
Authors: Cooley Keith R.
Published: February 2008

A theoretical analysis of the energy balance equation for a partially covered body of water indicates that surface reflectance for solar radiation and infrared emittance are important properties to consider in designing covers for maximum efficiency in reducing evaporation. White materials satisfy the requirement that both these parameters be as large as possible. Experiments were conducted on insulated evaporation tanks partially covered with foamed wax, lightweight concrete, white butyl rubber, and styrofoam. Several shapes and sizes were tested. The radiative properties of the cover were again noted to be important, and thin covers proved to be slightly more efficient than thick insulated covers. Evaporation reduction was proportional to the percent of surface area covered, the constant of proportionality depending upon the color and type of materials used. For the white, impermeable materials tested, the constant of proportionality was near unity. The reduction in evaporation was also highly correlated with the reduction in net radiation.
Digital Analysis of Areal Flow in Multiaquifer Groundwater Systems: A Quasi Three‐Dimensional Model
Authors: Bredehoeft J. D. , Pinder G. F.
Published: February 2008

A general solution for the response of multiple aquifer systems to pumping stress requires solving the three‐dimensional flow equations. The large number of arithmetic calculations and the excessive computer storage required for a numerical solution usually precludes solving the equations in three dimensions for typical hydrologic problems. When the hydrologic system is represented by aquifers in which flow is assumed horizontal, and confining layers in which flow is assumed vertical, the problem can be reduced to solving two‐dimensional equations for each aquifer, the aquifers being coupled through leakage. An iterative scheme is used to solve simultaneously the finite difference equations describing the response of confined and unconfined acquifers with or without storage in the confining layer.
A Moving Boundary Model of a One‐Dimensional Saturated‐Unsaturated, Transient Porous Flow System
Authors: Hornberger George M. , Remson Irwin
Published: February 2008

A moving boundary model is proposed for one‐dimensional transient flow of water through a porous medium of which part is saturated and part is unsaturated. The model is based upon a theory that implies a discontinuous propagation of pore pressure at the saturated‐unsaturated interface. The moving boundary model is used to study a gravity drainage problem. Two numerical procedures are developed to solve the problem, an approximate Taylor series method and a finite difference method. The validity of the methods was appraised by comparing the results with experimental data given by Watson [1967]. The Taylor series method is limited in applicability because of a need for accurate determination of derivatives of hydraulic conductivity and of moisture content respecting pressure head. The finite difference solution is very efficient because only changes in the unsaturated region are computed and the need for iteration is obviated.
New York Metropolitan Region—A Major Sediment Source
Authors: Gross M. Grant
Published: February 2008

Approximately 9.6 million tons per year of waste solids, including dredged sediment and construction debris from the New York metropolitan region, was dumped in New York Bight and in western Long Island Sound between 1964 and 1968. This was apparently the largest sediment source discharging directly into the North Atlantic Ocean (excluding the Gulf of Mexico) from the North American continent. Considering the core metropolitan region (population about 9 million) as the dominant source, the average annual discharge was about 1 ton per person (equivalent to about 6 pounds per person per day)
Turbulence Measurements Near the Free Surface of an Open Channel Flow
Authors: Holley E. R.
Published: February 2008

Turbulence spectrums were obtained from 0.006 inch to 1 inch below the free surface of an open channel flow with a depth of 6 inches and a mean velocity of 0.93 fps. No significant variation in the spectrums was observed for the different distances below the surface. The data tend to substantiate the presence of turbulence in the region which is sometimes called the surface film in reaeration studies.
Effects of Clear‐Cutting on Stream Temperature
Authors: Brown George W. , Krygier James T.
Published: February 2008

The principal source of energy for warming streams is the sun. The amount of sunlight reaching the stream may be increased after clear‐cut logging. Average monthly maximum temperatures increased by 14°F and annual maximum temperatures increased from 57° to 85°F one year after clear‐cut logging on a small watershed in Oregon's coast range. In a nearby watershed where strips of brush and trees separated logging units from the stream, no changes in temperature were observed that could be attributed to clear‐ cutting.
A Recursive Programing Model for Nonstructural Flood Damage Control
Authors: Day John C.
Published: February 2008

This paper deals with floodplain land use management approaches for urban flood damage control. These alternatives are important because traditional flood control projects, such as levees, channel improvements, and reservoirs, are not always capable of correcting the physical and economic conditions that give rise to flood damage. It is expected that land use management will complement engineering works and lead to more effective use and development of floodplain lands. The paper presents a computational technique for evaluating alternative land use assignments based upon the economic value a community gains from its land. A linear programing model is developed that identifies economically efficient combinations of (1) spatial and temporal planning of urban land use, (2) site elevation through landfill, and (3) flood proofing of buildings.
Multiple Gravity Wells under Transient States of Flow
Authors: Kashef Abdel‐Aziz I.
Published: February 2008

A method for finding the flow pattern of several wells pumped into an unconfined aquifer under transient conditions is presented. The study of the well group is based on the results of the study of individual wells using the relationships between the hydraulic forces. The method is based in part on some of the available concepts, especially those of Theis, Jacob, and Hantush. A flow equation called the ‘unified well formula’ is developed and written in terms of the areas of the pressure head diagrams across vertical sections. The form of this equation is valid for both artesian and gravity wells. The free surface of an individual gravity well is derived in a general procedure similar to that for steady state cases but introducing time effects. The equation can be solved numerically in one iterative cycle at a given time. The results of the analysis of single wells are used to determine the flow pattern of a multiple well system under transient conditions of flow. The pumping of all wells may not necessarily begin at the same time. The restricted superposition principles used in a previous paper on steady state cases are also used for transient flow. Dupuit's assumptions are eliminated and the circumferential velocities are neglected. The derived equations are further investigated at small radii or at large values of time after the start of pumping. The equation of the free surface reduces to the same form of the corresponding steady state cases. However, the radius of influence, in the transient case, depends on the time and the diffusivity of the flow medium.
Geometric Programing and the Preliminary Design of Industrial Waste Treatment Plants
Authors: Ecker J. G. , Mcnamara J. R.
Published: February 2008

The preliminary design of an industrial waste treatment plant is considered by using certain aspects of the relatively new theory of geometric programing. A computationally efficient technique of solution is proposed and applied to a well‐known problem previously solved by a dynamic programing approach.
Analysis of the Use of Distorted Hydraulic Models for Dispersion Studies
Authors: Fischer Hugo B. , Holley E. R.
Published: February 2008

The model ratios applicable to dispersion studies in distorted hydraulic models are investigated for both steady and oscillatory flow, and the effects of both vertical and transverse distributions of velocity on the dispersion process are considered. It is shown that simple transposition of concentration profiles from model to prototype is not valid and that models may magnify or reduce longitudinal dispersion depending on the geometry of the system. For that reason, physical models are unlikely to be useful for studies of pollutant dispersion.
Operational Hydrology for Ungaged Streams by the Grid Square Technique
Authors: Pentland R. L. , Cuthbert D. R.
Published: February 2008

The grid square technique has been used extensively in Canada for assessing water resource potential as well as for planning hydrometric networks. The method can conveniently be extended to generate synthetic streamflow traces on ungaged streams. The grid square technique and its extension to operational hydrology are discussed, along with an example from the New Brunswick region of Canada.
Derivation of Base Flow Recession Curves and Parameters
Authors: Singh Krishan P. , Stall John B.
Published: February 2008

The Boussinesq equation is used to show that base flow recession is an exponential decay function. For a single peaked hydrograph, the storage delay factor Kb, the time for base flow to decrease by a factor of 10, is estimated. The parameter Kb is adjusted by trial so that surface flow, or the observed total flow minus base flow, is also an exponential decay function after the point of inflection on the hydrograph recession. Surface flow Ks is so determined. For 22 basins in Illinois, dormant season Kb ranges from 15–100 days and is associated with physiography. Ks varies from 1.8–6.0 days.
Seepage through Unconfined Aquifers with Lower Boundaries of Any Shape
Authors: Youngs E. G.
Published: February 2008

An analysis of the seepage through unconfined aquifers with lower boundaries of any shape is presented. The differential equation describing the flow includes a term that involves the pressure distribution on the lower boundary. Although in many problems all the required pressure distributions that enable the seepage problem to be solved are not known exactly, an inspection of a given problem gives extreme values of any unknown terms with a final result of known precision. The application of the analysis, checked by electric analog experiments, is illustrated by two examples of seepage problems: first, the seepage over an inclined plane between two parallel ditches; and second, the seaward flow of fresh‐water fed by a freshwater reservoir or by rainfall and supported on saline water from the sea.
Two‐Stage Method of Pumping by Negative Pressure
Authors: Miller Robert J.
Published: February 2008

A two‐stage method of pumping liquids by use of negative pressure was developed which allows liquids to be raised to heights much greater than previously attained with vacuum. The principle of the method is simple and is controlled mainly by careful adjustment of positive and negative air pressures. The apparatus is inexpensive and easy to construct.
Spatial Allocation Model for Projected Water Based Recreation Demand
Authors: Tadros Mahfouz E. , Kalter Robert J.
Published: February 2008

This paper develops a model designed to distribute spatially recreation use estimates forthcoming from ‘structural demand’ equations of a recreation market. To illustrate the model's operation, a description of its empirical implementation for a regional case study area is given. Data needs and sources are specified, empirical results are set forth, and policy implications are drawn. The ability to use the model to simulate policy actions is pointed out.
Contribution of Atmospheric Chloride in Water from Selected Coastal Streams of Central California
Authors: Baldwin A. Dwight
Published: February 2008

Chemical quality and discharge data were collected and analyzed from five streams draining watersheds between Half Moon Bay and Santa Cruz, California, to determine the contribution of atmospheric chloride to these coastal basins. Fifty‐nine percent of the total chloride leaving the basins underlain by Tertiary sedimentary rocks per year is atmospheric in origin. Nineteen percent of this atmospheric chloride contribution is introduced dissolved in rainwater, whereas the remaining 40% is brought into the basins as fine particulate dust, in ‘fog drip,’ or as an aerosol.
A System of Waste Discharge Rights for the Management of Water Quality
Authors: Mar B. W.
Published: February 2008

Water quality management based on water quality standards and required waste treatment levels has serious informational and administrative problems. An alternative management system of marketable rights to change water quality is analyzed to stimulate a search for improved management tools. Such a system of rights can (1) simplify the problems in existing management systems of new discharger entry into a region, (2) incorporate the economic efficiency of the ‘effluent charge’ system and the regional management approach, and (3) provide a mechanism for government or the private sector to adjust the quality of water without creating serious economic penalties for other parties discharging waste or requiring high water quality. A marketable right to discharge waste into a specified area of water subject to the observance of a water quality standard at the boundaries of that area is proposed. Utilities would compete for major rights, whereas individuals would purchase minor rights from a utility. The utility would provide control of waste discharges that impact only segments of a body of water and an institution that could shift water quality above the standard.
Pollution Potential of Some New Hampshire Lakes
Authors: Dingman Lawrence S. , Johnson Arthur H.
Published: February 2008

A combination of simple water‐balance and mass‐balance equations produces an expression for the concentration of a dissolved pollutant in a lake as a function of time. Within this model are expressions characterizing (1) the lake equilibrium concentration, and (2) the rate at which equilibrium will be approached. These two parameters characterize the pollution potential of a lake. Pollution potentials for 23 New Hampshire lakes were evaluated and found to be closely correlated with lake size and drainage area.
Optimum Exploitation of Groundwater Reserves with Saltwater Intrusion
Authors: Cummings R. G.
Published: February 2008

The optimal intertemporal rate of exploitation of groundwater stocks in coastal areas with the intrusion of salt water is studied. A model is presented that focuses on the interrelated problems concerning the annual rate of pumping and the annual rate of investment in pumping equipment, and so forth, in which the effects of current decisions on future benefits are included (e.g., impacts of lower stocks and therefore higher future pumping costs, and increased rates of saltwater intrusion). Periodic extractions are carried to the point where the value of water in current use equals the marginal present value of water in storage. The value of water in storage includes marginal effects of current production on intrusion, pumping costs, and capital consumption. The conjunctively determined periodic rate of investment is that which equates marginal investment costs with the present value of future production attributable to larger pumping and distribution systems, discounted by depreciation rates.
Statistical Properties of Multivariate Fractional Noise Processes
Authors: Matalas N. C. , Wallis J. R.
Published: February 2008

Fractional noise processes belong to a class of stochastic processes that lie outside the Brownian domain of attraction. They are characterized by infinite memories and a parameter h that is the asymptotic slope of log (R/S) versus log N, where R is the range of cumulative departures from the sample mean, s is the sample standard deviation, and N is the sample size. The parameter h may be used to generate synthetic flows whose means, variances, skewnesses, lag one serial correlations, lag zero cross correlations, and h values are equal to those for historical flow sequences. Historical flow sequences yield values of h ≠ ½. Although Markovian processes, which belong to the Brownian domain, can preserve the values of the historical moments in the synthetic sequences, these processes generate sequences in which h tends to the value ½ as the sequence lengths tend to infinity.
Wintertime Dissipation of Heat from a Thermally Polluted River
Authors: Weeks W. F. , Keeler C. M. , Parrott W. , Levine D.
Published: February 2008

To test a method for predicting water temperature downstream from a source of thermal pollution on a cooling river, field observations were made below the Dave Johnson power plant (steam‐electric, 350 megawatts) at Glenrock, Wyoming, on the North Platte River. Roughly 30% of the average winter flow of 28 cubic meters per second is diverted through the plant, and the temperature of the cooling effluent is raised about 20°C. The site is ideal for heat balance studies because the amount of sheltering by either high banks or vegetation is minimal and there are no thermal pollution sources or major tributaries for 65 km below the plant. Meteorologic parameters were recorded at two sites on the river and water temperature profiles were measured at five cross sections located up to 28 km downstream from the plant. Above the plant, the river was ice covered and the water temperature was constant at 0°C. The observed temperature decreases below the plant were compared with the temperature decreases calculated by a previously developed method. Very satisfactory agreement between observed and calculated values was achieved when relations suggested by Rimsha and Donchenko were used to estimate the evaporative and convective heat losses. Other relations either gave a larger scatter or systematically underestimated the actual cooling.
High Head Permeability of Sand with Dispersed Clay Particles
Authors: Denson Keith H. , Wu Ping K.
Published: February 2008

High head permeability coefficients of sand‐clay mixtures were obtained for hydraulic gradients that ranged from 5.6 to 408. The sand had a mean diameter of 0.36 mm with a standard deviation of 0.20 mm. The clay constituent was Yazoo formation expansive clay that contained approximately 30% montmorillonite. Clay percentages varied from ½ to 2½%. The addition of 2½% clay at a constant hydraulic gradient of 408 reduced the coefficient of permeability by 56.8%. For the 2½% clay mixture, the coefficient of permeability decreased by 16.6% as the hydraulic gradient increased from 5.6 to 408. The permeability coefficient for pure Columbus sand decreased by 12% as the hydraulic gradient changed from 5.6 to 408.
An economic model of floodplain land use and land use policy
Authors: Brown John P. , Contini Bruno , McGuire C. B.
Published: February 2008

A landowner in a floodplain must choose a way to use his land from n available alternative activities. We develop a model that describes that choice as a function of the probability of a flood when the criterion is expected present value. We show the expected present value calculations for four simple benefit stream patterns: no‐decay, one‐hoss shay, experimental decay, and delayed benefits. Within this model we define and discuss several often elusive concepts: the damage due to one flood, the hazard due to being in the floodplain, and the benefits of flood probability reduction. We then show the relationship between the benefits of flood control and damage reduction, and point out that they are not identical. With this model we have a common framework for comparing such disparate flood relief and control policies as floodplain zoning and flood relief measures. Finally we show the misallocative effects of simple flood relief policies.
Cation adsorption in one‐dimensional flow through soils: A numerical solution
Authors: Lai Sung‐Ho , Jurinak J. J.
Published: February 2008

A numerical method was developed to solve the problem of the cation adsorption operation involving a general nonlinear exchange function. The method was applied to solve the cation adsorption operation involving five different types of exchange functions. The study showed that the adsorption of a cation depends on the equilibrium behavior of the counterions, which is defined by the exchange function. The separation factor αBA was used as an index of the adsorption operation.
Groundwater flow in a sandy tidal beach: 2. Two‐dimensional finite element analysis
Authors: Fang C. S. , Wang S. N. , Harrison W.
Published: February 2008

Two‐dimensional finite element techniques are described that model closely the complicated fluctuations observed in the water table of an ocean beach. The use of triangular elements permits the specification of more realistic boundary conditions than the use of line elements in a one‐dimensional model. Also, results obtained from the two‐dimensional model for the region close to the ocean compare more favorably with field data than results obtained from the one‐dimensional finite element model.
The accuracy of groundwater contour maps
Authors: Hanson Hal C.
Published: February 2008

The need for describing the accuracy of groundwater contour maps is explained. A method of making accuracy statements about groundwater contour maps is developed along with the necessary assumptions. The computer contouring package used in the accuracy tests is described briefly. Results of a limited number of map accuracy tests are presented in terms of dispersing differences of elevations and volume differences above a base. Applications of the method and results of the test are related to groundwater level network design. Other applications are suggested.
Precipitation Measurement Symposium: Introduction
Authors: Fletcher Joel E.
Published: February 2008

The precipitation committee organized a symposium given at the AGU National Fall Meeting in December 1969. The session contained seven invited papers:

1. Snow Measurement Predicament.

2. Weight Capacity Requirements for Precipitation Measurements in the Wasatch Mountains.

3. Precipitation Telemetry in Mountainous Areas.

4. Optimum Gaging of Thunderstorm Rainfall in Southeastern Arizona.

5. Rainfall Intensity‐Duration‐Frequency

Relations for the Wasatch Mountains of Northern Utah.

6. Measurement of Atmospheric and Ground Level Precipitation.

7. Variance Spectra of Short Duration Rainfall in Time and Space.
Weight capacity requirements for precipitation measurements in the Wasatch Mountains
Authors: Reynolds George W.
Published: February 2008

The reasonable readout resolution and the accuracy of the data from the telemetering precipitation measurement stations of the Wasatch Weather Modification Project are inversely related to the assigned measurement range. Consequently, provision for precipitation amounts much in excess of the amounts actually experienced results in an unnecessary loss of information. The results of this study indicate that for the winter season and insofar as the liquid water equivalent is concerned only a few locations need the 70‐inch capacity; 60 inches will suffice for most high altitude‐high yield stations; 36 inches is ample for low altitude‐high yield stations; 20 inches is more than adequate for low altitude‐low yield stations. Volume capacity requirements are somewhat higher because of the delay of melting in the collection can.
Precipitation telemetry in mountainous areas
Authors: Chadwick Duane G.
Published: February 2008

A battery‐operated telemetry system having high resolution and accuracy has been developed at the Utah Water Research Laboratory. The sysem is used for telemetering precipitation data from 45 remote mountain sites in the Wasatch and Uinta mountain ranges. At selected sites temperature, wind, and the water content of snow have also been telemetered. The use of a unique pick‐off sensor on the transducer also permits the system to be readily adapted to telemeter information from many recording‐type instruments such as a barograph.
Rainall intensity‐duration‐frequency relations for the Wasatch Mountains of northern Utah
Authors: Farmer Eugene E. , Fletcher Joel E.
Published: February 2008

The results of data analyses for 25 precipitation intensity stations in central and north central Utah at altitudes of 4350–10,150 feet are presented. All data were collected from May 1 to October 31. Each station has 10 or more years of record; one station has 30 years of record. Analyses were made of (1) record consistency, (2) definition of local precipitation zones, (3) intensity‐duration‐frequency characteristics, (4) 24‐hour depths, (5) monthly depths and number of storms, (6) storm occurrence by hour of the day, and (7) storm occurrence by storm duration. The precipitation zone at 6500–8000 feet altitude is expected to receive the greatest rainfall intensities. There is a trend toward reduced intensities with increasing elevation, but the trend is not uniform. However, those precipitation zones receiving the greatest intensity of rainfall do not coincide with those zones receiving the greatest depth of rainfall. Rainfall depth generally increases with altitude, but on one study area the zone of greatest depth was not the highest zone. There is a marked difference between the two study areas with respect to the distribution of storm occurrence by hour. This difference is attributed to differences in storm type and in the principal source of summer moisture. Average storm length varies inversely with altitude.
Estimation procedures for response functions of crops to soil water content and salinity
Authors: Yaron D. , Bielorai H. , Shalhevet J. , Gavish Y.
Published: February 2008

In this paper the specification and estimation procedures of the response functions of crops to soil water content and salinity are presented. The conceptual framework is discussed, and the application of the suggested procedures is illustrated by an analysis of two irrigation experiments. The possibility of positive correlations between soil salinity, soil water content, and crop yield is discussed, and possible erroneous evaluations of the effect of salinity on crop yield in such situations are pointed out.
A stochastic model of runoff‐producing rainfall for summer type storms
Authors: Duckstein Lucien , Fogel Martin M. , Kisiel Chester C.
Published: February 2008

Modification of watersheds occurs either through natural processes, such as erosion, or human influences, such as urbanization. In either case the rainfall input must be properly modeled before the runoff output can be predicted as the modifications take place. The paper considers runoff‐producing summer precipitation of short duration and high spatial variability as an intermittent stochastic phenomenon. The probability distribution of seasonal total point or areal rainfall is obtained by convoluting a Poisson number of events with a geometric or negative binomial probability of rainfall amount. Close agreement with the experimental data is found. Next the probability of various combinations of rainfall amounts, given the seasonal total and the number of events, is computed. With these results, the theoretical seasonal water yield distribution can be obtained by using a simple rainfall‐runoff relationship, such as the Soil Conservation Service formula. The possibility of using regional input parameters to study the distribution of the output of poorly gaged small watersheds is discussed. In particular, extreme total flows can be computed.
Runoff volumes from small urban watersheds
Authors: Miller Clayton R. , Viessman Warren
Published: February 2008

An empirical equation estimates the runoff volume from rainfall on small urban watersheds. If the rainfall is less than 1.5 inches, the runoff is predicted by the relationship between the percent impervious area in the watershed and the percent excess rainfall. An adjustment is made for the initial abstraction combined with the initial surface depression storage. For rainfall amounts greater than 1.5 inches, an additional increment of runoff is added for the pervious areas by using the hydrologic soil class, the vegetative cover, and the controlling parameters. Detailed 1‐ or 5‐min rainfall and runoff records from four small urban watersheds for 77 storms were used to develop the procedure. The method was tested on 17 additional storms on these watersheds. The maximum prediction error was 37% for over 80% of the test events. The median error was 17% of the actual runoff.
Dynamic multisector programing approach to regional water resource management
Authors: Bargur Jona
Published: February 2008

Market forces have failed in the areas of development, allocation, and management of natural resources in general and water resources in particular. The shaping of public investment programs for the development of water resources has long been dominated by partial equilibrium analyses such as benefit‐cost analysis. However, this approach is rather limited for an interregional and intertemporal management program of water resources. The present study offers a multisector planning and management approach to water resources that is based on a general equilibrium analysis employing input‐output models and linear programing techniques. A dynamic multisector programing model that takes into account the sectoral, spatial, and temporal aspects of regional planning and an extension to an activity analysis model are formulated and applied empirically to California and the western United States for a 15‐year planning horizon. The results of the empirical application include water requirement forecasts, interregional water transfer requirements, efficient production and cropping patterns, ‘shadow prices’ for water and labor, and an optimal investment program for water resource projects. The use of a general equilibrium programing model has made it possible to investigate problems of regional development that are dependent on the interrelationships between resource availabilities and sectoral planning and has illustrated the importance of the complex interdependencies among economic variables.
Residential water demand forecasting
Authors: Whitford Peter W.
Published: February 2008

Conventional methods of forecasting the future demand for municipal water supply give undue emphasis to historical rates of use, ignore many relevant factors, and fail to distinguish between components of use. This study is concerned with only the residential part of urban water use, and a forecasting model or framework for analysis is proposed. Six factors influencing future water use are regulations on the water used by appliances, type of pricing policy adopted, policy on public education, future housing patterns, cost of supply, and changes in the technology of use. Two or three outcomes are considered for each of these factors, and from combinations of these outcomes alternative descriptions of the future are formed. The cities of Baltimore and Phoenix are used as case studies to illustrate the method. For each case, a base line estimate is made that reflects past trends. The effect on the water use of each alternative future is estimated and the probabilities of each outcome are subjectively assigned. Thus a probability distribution of the future water demand is drawn.
Recreation benefit estimation and forecasting: Implications of the identification problem
Authors: Cicchetti C. J. , Smith V. K. , Knetsch J. L. , Patton R. A.
Published: February 2008

Recreation studies have in the past confused the terms demand and use. Demand refers to the schedule of quantities that the community will desire at all possible prices. Use or participation is the realization of both demand and supply considerations. Accordingly, a priori information in addition to the data must be supplied prior to the estimation of economic models of the recreation market. The identification problem assesses the sufficiency of such information. Since the type of information and the data themselves impose constraints on the specification, estimation, and use of economic models of the recreation market, a taxonomy of each applied study framed around a general equilibrium model of recreation decisions is presented, and the specific applied studies are discussed. A clear outline of the logical structure connecting the theoretical model with its empirical realization results from this taxonomy.
A multilevel approach to determining optimal taxation for the abatement of water pollution
Authors: Haimes Yacov Y. , Kaplan Michael A. , Husar Michael A.
Published: February 2008

Regional water quality management by a three‐level optimization approach is developed. Proposing the construction of a regional treatment plant, the central authority determines simultaneously the optimal treatment configuration for meeting water quality standards along a river basin and the optimal effluent charges necessary to realize this configuration. The optimal regional plant capacity and regional treatment level are also found, depending on which polluters decide to use the regional facilities. It is assumed that the central authority does not need to know the local treatment cost functions. Numerical results from simulated use of the technique with data for the Miami River basin reveal the efficiency and the effectiveness of the multilevel approach. Considerable savings over local treatment alone can be realized by employing regional treatment facilities.
Wave effect and eddy diffusivity in the air near a water surface
Authors: Cheng I‐Ming , Brutsaert Wilfried
Published: February 2008

The dynamic characteristics and the development of the underlying water waves were taken into consideration in the determination of the eddy diffusivity in the air close to a water surface. A relationship between the actual eddy diffusivity K and the apparent eddy diffusivity Kp, estimated purely from the wind velocity profile, was derived. The derivation was done in terms of (c/u* ), where c is the phase velocity of the dominant wave and u* is the friction velocity, and on the basis of experimental data obtained by Volkov in 1969 and 1970. It was found that the eddy diffusivity near the air‐water interface, determined in the usual way from the mean velocity profile, may lead to considerable error, depending on the sea state. The practical application of this result is illustrated in the determination of evaporation from a wavy surface.
Wind‐induced and thermally induced currents in the Great Lakes
Authors: Lee Kwang K.
Published: February 2008

A linearized stratified lake of rectangular shape with dimensions and other physical parameters comparable to those of the Great Lakes is presented to examine the currents induced by prescribed wind and thermal conditions at the boundary. The boundary layer of thickness E½ is identified at the surface and the solid boundary, where the wind and wall effects are most important. The influence of thermal input is restricted in the interior. The upwelling and downwelling phenomena and a relatively strong coastal current are significant in the linear stratified lake. Their relations to the input functions established in the analysis substantiate observations in the Great Lakes.
Sequencing of interdependent hydroelectric projects
Authors: Erlenkotter Donald
Published: February 2008

A dynamic programing model is formulated for the development of the hydroelectric potential of a river basin, with the objective of meeting power requirements projected over time at minimum discounted cost. Hydroelectric projects within the same river basin tend to be highly interdependent since upstream storage capacity creates technological external economies for downstream sites. These interdependences are accommodated within the model, and application to the sequencing of projects in a planning situation for a particular river basin demonstrates that these interdependencies do not increase significantly the difficulty of analysis.
Application of nonlinear system identification to the Lower Mekong River, Southeast Asia
Authors: Zand S. M. , Harder J. A.
Published: February 2008

The generalized functional series representation of systems was solved numerically by using a transformation of input that considerably reduces the computational difficulties and a multiple‐regression analysis that establishes an optimum model. Computer programs for constructing such models were applied in the construction of two models for the lower Mekong River. Both models have single outputs, the daily gage height of the river at Chaudoc, South Vietnam. One model is of the single‐input type, in which the input is the net average daily discharge below Phnom Penh, Cambodia. The second model is of the double‐input type; it has as a second input the daily rainfall at Takeo, Cambodia. A total of 1497 daily measurements from January 1, 1964, to February 5, 1968, were used in the analysis. The predicting capability of the technique was tested by using the model constructed for 1104 days as a predictor for the remaining 393 days.
Initial wetting losses incurred by ground level stereo gages
Authors: Sevruk Boris
Published: February 2008

The wetting losses of the rain catch of 32 galvanized ground level storage gages with stereo orifices were investigated for the period June through September to determine a correction for the monthly rainfall totals in the basin of the Bay of Montreux. The wetting of the gage per event as measured in the laboratory as well as in natural conditions ranged from 0.135 mm for the gage with a 15°‐inclined orifice to 0.205 mm for the gage with a 47°‐inclined orifice. The mean wetting correction of rain catch for 32 gages over a 10%year period for June through September amounted to 0.172 mm per event, or to 2.6% of precipitation catch. This percent varied only slightly in the respective years.
Forecasting water use for policy making: A review
Authors: Thompson Russell G. , Young H. Peyton
Published: February 2008

The derived demand function for water is the basis for forecasting water use in production. Substituting inputs in production is the key idea underlying derived demand functions for water. The form of the derivation is illustrated for certain types of substitutions in a steam electric generating plant. A linear method of approximating derived demand functions is discussed; references to previous studies in agriculture and petroleum refining are made. Several demand functions estimated in this way are then used to evaluate proposed investments in water resource regulation.
Market problems in the distribution of emission rights
Authors: Rose Marshall
Published: February 2008

An auction‐type bidding process is analyzed. A public authority distributes permits providing the right to discharge specified waste loads into a medium. Potential purchasers of the permits may perceive themselves as having some measure of control over the permit prices through their bids. It is shown that, given sufficient information on the nature of bidding strategies, the authority can infer the firms' marginal treatment cost functions from their bidding behavior and may therefore be in a position to impose the optimal solution of discharges.
Pathology of a dynamic programing sequencing algorithm
Authors: Morin Thomas L.
Published: February 2008

Two cases in which a conventional dynamic programing algorithm may produce non‐optimal solutions to an important class of sequencing problems encountered in water resource development are identified. The pathological behavior of the conventional dynamic programing algorithm is analyzed and illustrated with a counterexample. The use of the imbedded state space approach in the determination of optimal solutions in the two cases is discussed and illustrated by the solution of the counterexample. The extension of the imbedded state approach to the solution of more general combined selection and sequencing problems is also discussed.
Equation for one‐dimensional vertical flow of groundwater: 2. Validity range of the diffusion equation
Authors: Gambolati Giuseppe
Published: February 2008

The reliability in the operative field of the parabolic diffusion equation is investigated by solving the rigorous one‐dimensional equation of groundwater flow in deforming soils. The dependence of the hydraulic conductivity on the specific weight of water is included. The grain velocity is correctly expanded first. This expansion leads to a nonlinear integrodifferential term. An iterative finite element technique of solution is then developed. The true time‐dependent pressure head is compared to the standard one. The entire range of realistic variations for the formation parameters is carefully explored. It turns out that the usual equation gives satisfactory results in the vast majority of applications. The conditions underlying the approximated theory become critical only when the flow field is to be determined in highly compressible units for strong boundary pressure variations. In this case the solid material movements can no longer be considered small. The pressure head changes are faster than it would appear from the standard solution, and the consolidation process is more rapid than that in the classical Terzaghi's theory.
Method for numerical simulation of flow in multiaquifer systems
Authors: Saleem Z. A.
Published: February 2008

A model for simulation of groundwater flow in multiaquifer systems is developed. A system of nonlinear partial differential equations that are isomorphic to groundwater flow in the system is formulated in a finite difference form suitable for the line successive overrelaxation technique. The resulting system of difference equations is solved by using an efficient algorithm. The algorithm serves as a means for solving the bitridiagonal system of difference equations representing flow in two aquifers simultaneously. Storativity of the semiconfining layer can be considered indirectly or can be neglected. The results derived from the numerical simulator for the flow to wells in two coupled aquifers are in good agreement with analytical results for the same system.
The Impact of Man‐Made Lakes on Residential Property Values: A Case Study and Methodological Exploration
Authors: Day J. C. , Gilpin J. R.
Published: February 2008

Dams and reservoirs are often partially justified on the basis of an intangible benefit related to the property value changes that they allegedly induce. This assumption is tested by using the G. Ross Lord Dam and parkland on the west Don River in Toronto. The project had virtually no impact on residential property values in the summer of 1972 while the dam was under construction. The magnitude of the social benefit related to the residential land value changes induced by such a project is considered.