摘要:

Procedures for calculating returns per acre‐foot of water were developed in western United States irrigation projects and have been applied to supplemental irrigation in the humid eastern areas. These procedures constitute an operational definition of a marginal product of water, but the definition rests on a different theoretical basis in the two cases and does not apply to intermediate conditions. No general notion of marginal revenue of water appears meaningful for manufacturing uses, which are largely nondepleting. Comparisons made between the value of water in farming and in industrial uses are of doubtful value, particularly if they are extended to the humid regions. A method is proposed here for estimating the ‘marginal value’ of water intake in manufacturing. The method is based on the cost of the internal economy of water in an industrial plant. It may be used to compare the relative productivity of water in depleting and nondepleting uses, or to compare the returns to industry with the costs of public development of a water supply. Some estimates of marginal value are derived from data supplied by the Bethlehem Steel Company plant at Sparrows Point, Mar

ISSN:0043-1397    

DOI:10.1029/WR002i001p00001

年代:1966

数据来源: WILEY

摘要:

A new type of forecasting model of great potential for predicting flows in complicated spatial transportation networks is illustrated through application to the forecasting of interregional coal flows by barge over the Mississippi River system. Changes in these flows are related to regional coal production and consumption levels and to the freight charges by barge and rail. The special feature of the model is the great saving on the data needed for its implementation made possible by assuming that transportation patterns will be efficient, i.e., least‐cost, for given regional imports and exports. This assumption is incorporated by using the linear programming transportation method to generate individual flows from regional barge imports and exports forecasts by a system of statistically fitted equations. Various applications are illustrate

ISSN:0043-1397    

DOI:10.1029/WR002i001p00013

年代:1966

数据来源: WILEY

摘要:

Radioactive tracers introduced into the Columbia River in cooling water from the Hanford reactors were used to measure flow times downstream from Pasco, Washington, as far as Astoria, Oregon. The use of two tracer methods was investigated. One method used the decay of a steady release of Na24(15‐hour half‐life) to determine flow times to various downstream locations, and flow times were also determined from the time required for peak concentration of instantaneous releases of I131(8‐day half‐life) to reach these locations. Flow times determined from the simultaneous use of the two methods agreed closely. The measured flow times for the 224 miles from Pasco to Vancouver, Washington, ranged from 14.6 to 3.6 days, respectively, for discharges of 108,000 and 630,000 ft3/sec at Vancouver, Washington. A graphic relation for estimating flow times at discharges other than those measured and for several locations between Pasco and Vancouver was prepared from the data of tests made at four river discharges. Some limited data are also presented on the characteristics of dispersion of I131in the Columbia River. (Keywords: Radioactivity; time of flow; Columbia

ISSN:0043-1397    

DOI:10.1029/WR002i001p00031

年代:1966

数据来源: WILEY

摘要:

Nitrogen compounds in natural water are significant in public health, agriculture, industry, and geochemistry. The many sources of nitrogen compounds and the deep involvement of nitrogen in the life processes of organisms makes the study of such compounds difficult. The sources include natural aerosols, precipitation, fixation by micro‐organisms in soil and water, decaying organic matter, and animal and industrial wastes, as well as probably undiscovered sources in consolidated and unconsolidated rocks. Nitrogen compounds are both oxidized and reduced by organisms. Some nitrogen compounds are adsorbed on clay. The theoretical end product in water and the compound probably most often determined is NO3−1. The concentration of nitregen compounds ranges from 0.0 to>100 ppm (parts per million) in surface water and from 0.0 to>1000 ppm in groundwater. Seasonal fluctuations occur. Much further research is needed, including improvements in methods of analysis, further investigation of sources, and detailed study of the nitrogen cycle in small drainage basins. (Key words: Geochemistry; quality of wat

ISSN:0043-1397    

DOI:10.1029/WR002i001p00041

年代:1966

数据来源: WILEY

摘要:

The biodegradable content of organics in aqueous solution can be assessed in two ways: by measuring the change in organic content effected by bacterial metabolism; or by measuring the consumption of oxygen by bacteria in effecting the removal of organics. In addition to oxygen, two possible parameters for pollution measurement are thermodynamic energy change and total carbon change. The validity of applying thermodynamic concepts to biological systems is questioned. Total carbon changes during the process of biological oxidation are considered to offer an excellent potential as a measure of biodegradable organic content. The use of carbon as a parameter in the context of the two analytical procedures derived at Rice University affords a flexibility in selection of technique based on the required precision of results. (Key words: Pollution measurement; oxygen demand; bacterial synthesis.)

ISSN:0043-1397    

DOI:10.1029/WR002i001p00059

年代:1966

数据来源: WILEY

摘要:

The stomata of plant leaves constitute a main regulating system of the transpiration process. Biologists have suggested a turgor mechanism to explain stomatal movement. The functions of the mechanism are quantitatively described by an osmotic water transfer theory and/or the active water transfer theory in the guard cells. Based on the active water transfer theory and the observations of stomatal movement under various conditions of H2O, CO2, and light, a conceptual model of the stomatal control mechanism is proposed. Transfer functions of the mechanisms characterizing the changes in turgor pressure have been derived. The entire system has been organized by the application of adaptive control system theory and has been simulated on an analog computer. The dynamic characteristics have been investigated with consideration of various environmental conditions. (Key words: Computers, analog; plants; soil moisture.)

ISSN:0043-1397    

DOI:10.1029/WR002i001p00071

年代:1966

数据来源: WILEY

摘要:

Plant life processes are related in a complex way to the balance between the water demand of the atmosphere and the availability of water to the plant root. An exploration of the dynamic status of water in the plant is very important. As an approach to an integrated analysis of the dynamic system of water movement through the soil‐plant‐atmosphere continuum, a simulation model of the transpiration process is presented. Van den Honert suggested the use of Ohm's law describing water flow into, through, and out of plants. In the present study, this hypothesis has been expanded to include an analogous storage factor to deal with the dynamic flow of water in the plant. A set of differential equations and transfer functions is expressed in terms of water suction variables. The dynamic description of the water status in the plant is completed by introducing the system gain, which is a function of both the transpiration rate and the soil‐water condition. The dynamic system gain is realized by a method similar to Corbin's method of a computer‐controlled adaptive control system. The entire system is then simulated on an analog computer; its dynamic characteristics are investigated with consideration of various environmental effects. (Key words: Computers, analog; plants; soil mo

ISSN:0043-1397    

DOI:10.1029/WR002i001p00085

年代:1966

数据来源: WILEY

摘要:

Near Buckeye, Arizona, five evapotranspirometers were installed in the fall of 1962. Water losses were measured from these tanks, two of which were planted to salt cedar and the other three kept bare. Rates of water loss from vegetated tanks plotted against time show a diurnal wave wih a maximum loss in the early afternoon of hot summer days. The losses from bare tanks so plotted show two maximums. The rate drops sharply during the middle of the day. Harmonic analysis reveals that the second harmonics of both curves are nearly identical in amplitude and phase angle. Later in the season the second harmonic of the vegetated tanks disappears. Certain unexplained anomalies remain in the analyzed data. (Key words: Evapotranspiration; soil moisture; lysimeters.)

ISSN:0043-1397    

DOI:10.1029/WR002i001p00099

年代:1966

数据来源: WILEY

摘要:

Ice storage changes for the South Cascade Glacier drainage basin were determined for the 1957–1964 period using basin runoff and precipitation measurements. Measurements indicate that evaporation and condensation are negligible compared with the large runoff and precipitation values. Runoff, measured by a stream discharge station, averaged 4.04 m/yr; precipitation, determined by snow accumulation measurements at a central point on the glacier and by storage gages, averaged 3.82 m/yr, resulting in a basin net loss of about 0.22 m/yr. During the same period, South Cascade Glacier net budgets were determined by ablation stakes, snow density‐depth profiles, and maps. The average glacier net budget for the period was −0.61sol;yr of water. This amount is equivalent to −0.26 m of water when averaged over the drainage basin (43% glacier‐covered), which is in fair agreement with the net storage change measured by hydrologic methods. Agreement between the two methods for individual years is slightly less perfect. (Key words: Glaciers; water

ISSN:0043-1397    

DOI:10.1029/WR002i001p00105

年代:1966

数据来源: WILEY

摘要:

As a result of advances in high speed digital computers, considerable interest has been shown in the use of a numerical solution of the complete equations of free surface flow to synthesize the unsteady channel and overland flow conditions that occur during a period of runoff. The advantage of this approach is that it provides a logical description of the phenomenon of local inflows entering along a stream flowing at either subcritical or supercritical velocities. This paper shows the feasibility of the approach by comparing the hydrographs and water surface profiles obtained from a numerical solution of the equations with those produced by introducing time varied and spatially varied lateral inflows along the length of a 72‐foot‐long experimental flume. One of the practical problems found with the numerical technique was a sensitivity to errors in the value of the Manningnused to describe the channel roughness. The difficulties imposed by this sensitivity are discussed and compared with the problems associated with traditional routing methods. (Key words: Flood routing; hydraulics; computers, digital; synthes

ISSN:0043-1397    

DOI:10.1029/WR002i001p00111

年代:1966

数据来源: WILEY