Water Distribution Pattern Research Articles

Indications of progressive desiccation of the Transvaal Lowveld over the past 100 years, and implications for the water stabilization programme in the Kruger National Park

All available rainfall statistics recorded for the Kruger National Park area since 1907, coupled with an analysis of all the historical climatological data on hand, appear to confirm the quasi-twenty-year rainfall oscillation in precipitation pattern for the summer rainfall area. This was first pointed out by Tyson & Dyer (1975). The dendrochronological data obtained by Hall (1976) from a study of growth rings of a very old yellowwood tree (Podocarpus falcatus) in Natal, also appear to indicate a superimposed, long-term (80-100 years) pattern of alternate below- average and above-average rainfall periods. The historical data relating to climate in the park, during the past century or two, seem to bear out such a pattern. If this can be confirmed, it will be an enormous aid not only in wildlife-management planning, but also to agriculturists, demographic planners and others. It would appear that the long, relatively dry rainfall period of 1860-1970, with its concomitant progressive desiccation of the @ area in question, has passed over into the next aboveverage rainfall era. This does not mean that there will be no further cataclysmic droughts during future rainfall trough periods. It is therefore wise to plan ahead to meet such contingencies. The present water distribution pattern in the park (natural plus artificial water) is conspicuously still well below that which pertained, during dry seasons, at the turn of the century, when the Sabi and Shingwedzi game reserves were proclaimed. It is the declared policy of the National Parks Board of Trustees to simulate natural regulating mechanisms as closely as possible. In consequence the artificial water-for-game program is a long way from completion. The large numbers of game animals in the park (including dominant species such as elephant Loxodonta africana and buffalo Syncerus coffer) can no longer migrate out of the area to escape natural catastrophes (such as the crippling droughts of 1911-1917, the 1930s, 1940s and 1960s), and a reliable supply of artificial water in all the areas where natural supplies have dried up since 1902 should be provided, to prevent an irreversible population crash of many animal species during future periods of protracted drought. Such a catastrophe could well spell the end of the park as a viable, self-sustaining wildlife sanctuary and destroy its well-established tourist industry. Special measures will have to be taken to safeguard the perennial rivers of the park and their unique aquatic life from the calamitous effects of progressive desiccation or serious pollution.

Evaluating the effect of non-uniform and deficient irrigation—Part II

The present study is based on a mathematical model for predicting the yield reduction from non-uniform and deficient irrigation. Two simplifications are introduced in an attempt to reach practical results. Namely a linear yield function for the entire growing season is used and the water distribution pattern is presented by standard statistical distributions such as the Normal and Pearson type 3. Using an analytical approach a simple equation is obtained for quick prediction of crop yield. A numerical example is included and a sensitivity analysis is carried out. The method can be used for optimization of design parameters in sprinkler irrigation systems.

Distribution of Water in Hailstones

A large number of photographs of thin sections of quenched hailstones have been studied to determine the most common patterns of water distribution within hailstones. The way in which water is distributed throughout the hailstone determines which of the mixing rules should be used to calculate an effective refractive index of water-ice mixture. We have concluded that the Maxwell-Garnett mixing rule for ice grains embedded in a water matrix is suitable for most graupel soaked with water. Some of the large hailstones with spongy growth suggest that a proper generalization of the Bruggeman mixing rule should be used to determine their effective index of refraction at centimeter wavelengths.

The role of extracellular sodium in isosmotic intracellular regulation in the respiratory tree of Holothuria glaberrima

1. 1. Respiratory trees of Holothuria glaberrima exposed to solutions in which sodium has been replaced by choline, Tris pH 6.1, Tris pH 8.0 or lithium show a net loss of intracellular water, potassium, sodium and chloride. Intracellular content of neutral orgainc osmotic effectors remains unmodified. 2. 2. Extracellular lithium and Tris pH 8.0 decrease intracellular potassium concentration to half that in sodium, choline and Tris pH 6.1. Intracellular sodium concentration falls markedly while that of chloride falls moderately in sodium-free solutions. Sodium substitutes appear to enter the cells. 3. 3. A model based on Donnan considerations accounts for the patterns of ion and water distribution.

Nonuniform Sprinkler Irrigation Application Efficiency

Universal relationships between application efficiency, statistical properties of water distribution pattern, and the application ratio are developed assuming that the application depths observe gamma distribution when asymmetrically distributed and normal in the symmetric case. Results for the positively skewed gamma distribution and the normal distribution are extrapolated to treat the negatively skewed applications. These relationships agree with those obtained numerically by other authors from observed distribution patterns. Application efficiency is shown to increase with positive asymmetry for minimum application depths equal to or less than the average depth. Negative asymmetry and larger applications have the oppositive effect on application efficiency. The results are presented in standard units that permit ready evaluation of application efficiency and other parameters for various irrigation systems having different uniformity characteristics.

INSTITUTIONALIZED INEFFICIENCY: THE UNFORTUNATE STRUCTURE OF COLORADO'S WATER RESOURCE MANAGEMENT SYSTEM1

ABSTRACT: This analysis identifies two basic structural features of Colorado's water management system which inhibit constructive reform and perpetuate inefficiencies in water use and distribution patterns. These features are: (1) the fragmentation of authority and influence over water, and (2) the estrangement of interest in reform from formal control over water policy. These interrelated features have continued to produce: sporadic, high conflict battles over proposed changes in the status quo; decision making which tends to exaggerate the importance of narrow, special interests while virtually ignoring legitimate interests of major sectors of the public; an inertia which discourages innovation; and an agglomeration of rules and water rights that are predicated on obsolete social and economic needs. Two radical proposals for reforming the state's water resource management system in order to overcome these problems and to enhance the probability that wise water policy will result are offered. These proposals are: (1) the abolition of the present system of water rights founded on the doctrine of prior appropriation, and (2) the consolidation of authority over water allocation in a single board of governors.

HACKENSACK ESTUARY OIL SPILL: CUTTING OIL-SOAKED MARSH GRASS AS AN INNOVATIVE DAMAGE CONTROL TECHNIQUE

On May 26, 1976, a two million gallon oil spill, originating at a riverside bank farm in Jersey City, New Jersey, struck the Hackensack River estuary. Booms failed and the oil moved upriver, coating shores, marshes, creek banks, bulkheads, marinas, and the Sawmill Creek Wildlife Management Area. On-going hydrology research in velocity and water distribution patterns provided for predictability of slick movement. Search for corrective measures and the advice of a network of scientists led to implementation of an innovative grass-cutting technology. Analysis from the current five month oerspective indicates the advisability of a quickly-implemented cutting operation where tidal flushing is poor, and the high potential for natural cleansing where oil has reached low-lying, well-washed marsh areas.

Traveling Gun Application Uniformity in high Winds

ABSTRACT FIELD tests of a traveling gun sprinkler irrigation system showed that increases in wind velocity must be accompanied by decreases in travel lane spacing if an acceptable water application uniformity is to be maintained. Travel lane spacing must be decreased further as the wind direction and travel direction become more nearly parallel. An empirical equation is presented to estimate lane spacing as a function of wind velocity and direction, and sprinkler water pressure, for the sprinkler tested. If travel lane spacings recom-mended for no-wind conditions are used, the water distribution pattern during winds will become uneven. If recommended lane spacing reductions for windy conditions are followed, the application pattern during winds may be acceptable under some wind directons; however, if winds are nearly parallel to the travel direction the application pattern will be poor. Also, if the narrower spacings recom-mended for winds are used, the application pattern may be poor if the wind velocity decreases. Spacings from 30 to 75 percent of the wetted diameter gave acceptable uniformity with no wind. Uneven water distribution results in too little water applied in some field areas, which reduces crop yield; and too much water applied in other areas, which will cause deep percolation, resultant loss of nutrients, higher energy costs, and reduced crop yield. The importance of uniform irri-gation water application increases as the costs of land, irrigation equip-ment, water pumping, and fertilizer increase. Nonuniform application results in water and nutrient loss from deep percolation, with resulting ground water pollution, as well as under-irrigation and yield reduction in some field areas. In West-central Minnesota, where irrigation is increasing on shallow, drought hazard soils and where winds are prevalent during the cropping season, the amount of acreage irri-gated by traveling large volume, single nozzle gun irrigation systems is increasing. This report describes a study to investigate the performance of a traveling gun sprinkler and to develop operating procedures that would provide an acceptable water application uniformity when operating in windy conditions. A coefficient of uniformity (CU) of 0.85 or better, was considered acceptable. Coefficient of uniformity was calculated from Christiansen's formula: Values of CU were calculated for various travel lane spacings, using calculated overlapped application depths. The maximum lane spacings to obtain a CU value of 0.85 was determined for each test. Also, maxi-mum travel lane spacings were calculated from an equation devel-oped previously from stationary tests (Shull et al.)(No date) and were compared with the spacings obtained from the traveling gun data, to determine the equation's utility as a general guide for predicting travel lane spacing for various wind veloci-ties and directions

Wind, Sprinkler Patterns, and System Design

Sprinkler water distribution data were analyzed to show the distorting effect of wind on the distribution pattern. It was found that the drift loss was neglible, and that the wind did not have a significant direct effect on the evaporative water loss. The individual distribution patterns were then reconstructed to a state of no-loss, exhibiting the now isolated distortion effect. The reconstructed patterns were used to test computationally an intuitive design rule which states: To produce the best possible water distribution under the major constraints of a given sprinkling system, the centers-of-mass of the individual water distribution patterns (rather than the sprinklers themselves) should be equidistantly spaced in the field. Three design examples seeking optimal lateral direction, operation-shift timing, and distance between lateral working positions were worked out. The resulting designs were checked by means of a detailed superposition program and found to be very close to the optima.

Analysis of water distribution from rotary sprinklers

The nature of the water distribution pattern observed from rotary sprinklers has been analysed. Results show that the distribution pattern can be adequately characterized by a Beta distribution function. Values of distribution coefficients based on an incomplete Beta function have been derived for sprinkler systems. A range of minimum and maximum depths in sprinkler systems is predicted by the Beta distribution.

Symposium on Thermal Waters: Papers solicited

A call for papers has been issued for the International Symposium on Thermal and Chemical Problems of Thermal Waters, to be held during the Sixteenth General Assembly of the International Union of Geodesy and Geophysics (IUGG) on the campus of the University of Grenoble, France, August 29–September 1, 1975. Sponsors of the symposium are the International Association of Hydrological Sciences (IAHS) and the International Association of Volcano logy and Chemistry of the Earth's Interior (IAVCEI).The program will consist of invited and offered papers on thermal water distribution patterns, geothermal zones of the earth's crust, geochemistry of thermal waters in various regions, utilization of the heat components of thermal waters, and thermal pollution.

Two Classroom Exercises Demonstrating the Pattern of Container Soil Water Distribution1

Abstract The soil water distribution pattern in a container soil is simulated using cellulose sponges as an analog of container soils. Two classroom exercises are presented that have been successful in both classroom and extension presentations to horticulturists.

Subsurface Irrigation System Analysis and Design

By considering the phenomena of subsurface irrigation as a case of two-dimensional infiltration, a method is developed for analyzing the water distribution pattern in the soil profile from a subirrigation pipe placed on a barrier. Equations of soil-water movement were used to establish the design criteria of the discharge, the burial depth and the spacing of the subsurface irrigation system. A numerical example is given to show the procedures of the proposed method for subsurface irrigation system analysis and design.

An attempt to reproduce experimentally the pattern of salt and water distribution of age in the young neurohypophysectomized adrenlectomized rat.

Previous studies of the interaction of aldosterone, vasopressin, and corticosterone in the neurohypophysectomized adrenalectomized rat suggested that the salt and water distribution pattern in the muscles of the aged rat and that observed in simple aldosterone dominance were similar. This was tested by maintaining young neurohypophysectomized adrenalectomized rats with aldosterone alone for 3 months and comparing the resulting pattern with that of old rats, 27 months of age. Changes identical with those which occur spontaneously in the aged muscle, although of lesser degree, were reproduced in the young animals. Thus, total muscle sodium increased in association with a corresponding loss of potassium and a shift of water from cells to environment. As in the old animals, an increase in total muscle water was observed.

Adrenal cortex and neurohypophyseal deficiency in salt and water homeostasis of rats.

The role of adrenal cortex and neurohypophysis in controlling the equilibrium distribution and handling of water, sodium, and potassium was studied for a 2-week period in rats deprived of these glands. Adrenal deficiency is characterized by a loss of sodium from both extracellular and intracellular compartments (gastrocnemius, aorta) and a shift of water into cells. The sodium gradient, [Na]o/[Na]i, remains relatively unchanged. There is a marked fall in the potassium gradient, [K]i/[K]o, due in large part to the shift of water and in smaller part to a translocation of potassium. Neurohypophyseal deficiency is characterized mainly by an increase in intracellular sodium both in amount and concentration. A salt load administered by stomach tube tends to be excessively retained when cell sodium is low and excessively rejected when it is high. Animals deprived of both adrenal and neurohypophyseal function show an intermediate pattern. The pattern of salt and water distribution in either deficiency thus depends in part on the activity of the remaining gland. It is suggested that adrenal insufficiency and diabetes insipidus are counterpoint states.