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Showing papers in "Journal of The American Water Resources Association in 1972"



Journal ArticleDOI
TL;DR: In this article, the influence of a forest on the formation of steps in two small streams of the Colorado Rocky Mountains was studied, and it was shown that the average step length between logs and gravel bars was strongly related to channel gradient and median bed material size.
Abstract: The influence of a forest on the formation of steps in two small streams of the Colorado Rocky Mountains was studied. Steps provided by logs fallen across the channel added to flow energy reduction. The streams required additional gravel bars to adjust to slope. Average step length between logs and gravel bars was strongly related to channel gradient and median bed material size. Based on the average number of log steps per 50 feet of channel, an average of 116 percent of gravel bars were added at Fool Creek and 60 percent at Deadhorse Creek. The latter had 52 percent more logs in the channel and therefore required less bed material movement than the former. Although these are “rushing mountain streams,” most flow velocities ranged between 0.5 and 2.5 f.p.s. Exponents of a function relating rate of change of depth or velocity to discharge indicated that dynamic stream equilibrium was attained. Implications for forest management are that sanitation cuts (removal of dead and dying trees) would not be permissible where a stream is in dynamic equilibrium and bed material movement should be minimized.

141 citations


Journal ArticleDOI
TL;DR: In this article, a 1,067-acre drainage basin in Durham, N.C. was characterized to determine yield of pollutants and the major long-term pollutional impact on a projected downstream reservoir was considered to be the fixed solids residue and longterm oxygen demand.
Abstract: Urban storm water from a 1,067-acre drainage basin in Durham, N.C. was characterized to determine yield of pollutants. Population density averaged 9 persons per acre (ranging from <3 to 16). Annual BOD contribution attributable to surface wash during storms was determined to be approximately equal to contribution by its secondary wastewater treatment plant effluent. Total organic matter (COD) was estimated to exceed the amount in raw sanitary sewage from a residentially developed area of the same size. Mean basin yields (Ib/acre/day) were: BOD-0.23, COD-2.85, Total Solids-43.6, Volatile Total Solids-4.8, Total Phosphate-0.01 and Chloride-0.20 (as NaQ). The yield of lead presumed to originate from internal combustion engines operating on and near the basin was determined to be 0.006 Ib/acre/day. The concentration of total pesticides (Dieldrin; p,p'DDE; p,p-DDT; p,p'DDD and p,p'DDT) weighted for flow significance was estimated to be 1.2 parts per billion. The major long-term pollutional impact on a projected downstream reservoir was considered to be the fixed solids residue and long-term oxygen demand (COD). Intermittent release of other pollutants in slugs during runoff periods may be a significant factor in causing undesirable effects in streams draining urban areas.

49 citations


Journal ArticleDOI
TL;DR: In this article, the authors applied harmonic analysis to daily mean air, water temperature records for a location and found that the first harmonic accounts for a major portion of the total variance in the records.
Abstract: . Application of harmonic analysis to daily mean air, water temperature records for a location indicates that the first harmonic accounts for a major portion of the total variance in the records. Water temperature residuals are well correlated with air temperature residuals. Parametric values of the mathematical model for predicting water temperatures from air temperature records are stable from year to year. The air-water temperature relationship appears to be a stationary linear process. Consequently, it is possible to predict water temperatures at a location from the ambient temperature records provided both air and water temperature records are available for another similarly situated water body.

33 citations


Journal ArticleDOI
TL;DR: In this article, a set of decision rules have governed the traditional politics of water development, including local support, agreement, mutual accommodation, mutual noninterference, and fairness and equity.
Abstract: A set of decision rules have governed the traditional politics of water development. This paper identifies these rules, describes their operation, and explains the logic behind their adoption. Personal interviews with a large number of decision makers are cited to substantiate and illustrate particular rules. There are five decision rules: local support, agreement, mutual accommodation, mutual noninterference, and fairness and equity. These guidelines are intended to insure support, lessen conflict, and protect the reputation of water development as a worthwhile federal investment. Since there are current indications that the traditional decision rules are no longer followed, the paper aims to identify why and how the rules are changing.

33 citations


Journal ArticleDOI
TL;DR: The use of salt to melt ice and snow on streets and roads has become prevalent throughout the Northeast as mentioned in this paper, and several states apply as much as 20 tons per lane-mile.
Abstract: The use of salt to melt ice and snow on streets and roads has become prevalent throughout the Northeast. Several states apply as much as 20 tons per lane-mile. Salt runoff may be sorted in various locations within the hydrologic system. Eventually the salt reaches streams and lakes. In Meadowbrook, it was observed that the chloride content reached a high of 11,000 ppm in December 1969. The runoff from the watershed was emitted in several surges. Chloride concentrations declined with the onset of summer, but still remained high, suggesting that some of the salt applied during the past winter appeared in the summer stream flow. Salt runoff entering a small lake, flowed directly to the lake bottom. The buildup of high density saline water in the lower portion of the lake prevented complete mixing in the spring. Incomplete mixing led to anoxic conditions in the lower lake strata. The population of bent hic fauna of the lake was changed by the flow of salt water into the lake. From a total of 10 species of dipteran larva and oligochaetes, only 4 species of the latter remained.

32 citations


Journal ArticleDOI
TL;DR: In this paper, the authors examined the recreational experiences of two groups of users as they were affected by levels of use on three intensively used lakes in southeastern Michigan during the summer of 1969.
Abstract: The tremendous growth of participation in recreational boating has focused attention on the ability of surface waters to support different types of water-based recreation under intensive use. An important factor in determining the capacity of recreational waters for boating is the satisfaction boaters derive from an area and its use. The recreational experiences of two groups of users as they were affected by levels of use were examined on three intensively used lakes in southeastern Michigan during the summer of 1969. The reactions toward levels of use were obtained from personal interviews with users at the access sites following participation and by self-administered questionnaires distributed to shoreline property owner users. The level of use was recorded by aerial photography at hour intervals. The dispersion of boats and area consumed by boats on the water surface areas over time were quantified and investigated individually and in combination for possible relationships describing the level of use. The satisfaction of users was defined in terms of an index calculated by dividing the number of unfavorable boater responses by the total number of responses for a given time and place. Definite mathematical relationships between levels of use and user satisfaction were established. Based on these relationships, a range of levels of satisfaction for various numbers and groupings of boaters was used to develop boating carrying capacity limits.

22 citations



Journal ArticleDOI
TL;DR: In this article, two factors affecting the centralization of wastewater treatment facilities were investigated; the cost of collection and treatment systems and the performance of treatment plants, based on computer-generated minimum cost designs, wastewater collection networks were found to be characterized by diseconomies of scale of magnitude similar to the reported economies of scale for wastewater treatment works.
Abstract: . Two factors affecting the centralization of wastewater treatment facilities were investigated; the cost of collection and treatment systems and the performance of treatment plants. Based on computer-generated minimum cost designs, wastewater collection networks were found to be characterized by diseconomies of scale of magnitude similar to the reported economies of scale for wastewater treatment works. The combined costs of collection and treatment are U-shaped functions from which the least cost size of collection and treatment systems were found for particular values of population density. Examination of the day-to-day performance of five metropoitan-area waste-water treatment plants revealed that, for time series shorter than one month, the day-to-day variation in effluent quality was random, although the variation in quantity discharged was distinctly non-random. The performances of all five plants on any given day showed little correlation. This suggests that the decentralization of treatment facilities can produce benefits both through the reduction in quantities of waste discharged at a given point and through in-stream averaging of the varying performances of several treatment plants. Since the cost function of collection and treatment combined is generally flat in the region of the minimum-cost size, little penalty is invoked to gain the potential benefits of treatment plant decentralization.

21 citations


Journal ArticleDOI
TL;DR: This paper presents computational results to complement the theoretical discussions on the multilevel approach and the physical interpretation of effluent charges imposed by the regional authority on each user (polluter) is given.
Abstract: . A regional authority is postulated as the pollution abatement agency. The authority's task is to minimize the total cost of waste treatment to the region. Data from the Miami River in Ohio are used to model a twenty-seven reach river with fifteen BOD dischargers. The description of the system model is given in terms of linear inequality constraints and a quadratic objective function. The multilevel approach with a two level optimization hierarchy in then applied. The river system model is decomposed into twenty-seven subsystems (reaches). At the first level (local level), each subsystem is “independently” optimized. At the second level (regional level) the subsystems' solutions are coordinated to yield an overall optimum to the whole region. Two types of second level coordination schemes are presented for the decentralized decision making process. The first assumes a knowledge of the local treatment cost functions by the regional authority; the other assumes no such knowledge. A discussion of the multilevel optimization approach and the coordination algorithms for both schemes is presented. In addition, the physical interpretation of effluent charges imposed by the regional authority on each user (polluter) is given. This paper presents computational results to complement the theoretical discussions on the multilevel approach [Haimes, 1971a].

20 citations


Journal ArticleDOI
TL;DR: In this article, an exact solution of the oxygen balance equation is presented as a method for calculating primary production in streams, which is shown to be well suited to the ultimate goal of studying energy budgets of streams, and thereby the eutrophication process.
Abstract: . A promising technique for recognition of early stages of cultural eutrophication relies on determining production and respiration in streams. The most successful and most widely used method of estimating production of a segment of a stream is the upstream-downstream, diurnal curve method introduced by Odum [1956]. This technique is equivalent to obtaining an approximate solution to the oxygen balance equation. We report here an exact solution of the balance equation as a method for calculating primary production. Data presented by Owens [1966] are analyzed; effects of depth and oxygen saturation are studied. A major advantage of the method described here is that continuous temporal variation of net production may be rigorously handled. The method is shown to be well suited to our ultimate goal of studying energy budgets of streams, and thereby the eutrophication process.

Journal ArticleDOI
TL;DR: In this paper, the efficiency of an inverted internal hydraulic jump as a mixing and dispersion mechanism in an aquatic environment was examined, where the main object was to find the conditions under which a turbulent mixing zone occurred and the rate of turbulent entrainment.
Abstract: The efficiency of an inverted internal hydraulic jump as a mixing and dispersion mechanism in an aquatic environment was examined. The flow considered was a two-dimensional buoyant flow from a shallow channel over a sloping bottom into a deep reservoir. It could be seen that a rapidly varied flow associated with violent turbulent mixing occurred near the point of discharge if specific discharge conditions and downstream controls were met. Downstream from the mixing zone the flow was stably stratified. The main object of the study was to find the conditions under which a turbulent mixing zone occurred and the rate of turbulent entrainment. Energy loss and length of the mixing zone were also investigated. The independent variables were the outlet densimetric Froude number, the density differential between outfall water and receiving water, the relative depths of the upper and lower layers in the stratified flow portion, the total depth, and the slope of the transition. Theoretical calculations had to be confined to a step increase in depth, but experiments in a laboratory flume showed that results obtained with slopes of 23° and 90° were quite similar. Both theory and experiments showed, for example, that dilution (entrainment rates) up to 2:1 (2 parts heated water to one part cold water) can be achieved at very little energy expense and with downstream depths approximately 8 times the outlet depth. Theoretically, any amount of dilution can be obtained, but large depths may be required. Experimental results also indicate that the length of the mixing zone was frequently ten times the value of the outlet densimetric Froude number.

Journal ArticleDOI
TL;DR: In this paper, the steady-state, unconfined flow of a homogeneous fluid through jointed rock is studied for both laminar and turbulent conditions by use of a method which is based on previously developed theoretical and experimental flow relationships.
Abstract: The two-dimensional, steady-state, unconfined flow of a homogeneous fluid through jointed rock is studied for both laminar and turbulent conditions by use of a method which is based on previously developed theoretical and experimental flow relationships. However, only the independent unknowns are selected in order to reduce the complexity of the problem and render it more readily tractable. The intact rock is assumed to be impermeable, and two intersecting systems of plane, parallel joints are used in the mathematical model, taking into account the surface roughness of the joints. The mathematical solution of the resulting nonlinear (due to turbulent flow in some joints) system of equations is obtained by use of a rapidly converging iterative procedure, wherein each iteration takes special advantage of the banded nature of the associated matrix. For the particular case where a free surface exists, the general flow equations are not satisfied, because some of the joints in the vicinity of the free surface do not flow full; therefore, new equations must be established to handle this condition. Once the development of the mathematical model is accomplished, several cases involving different geometric characteristics (width, orientation, and roughness of joints) are solved for a rectangular domain, and graphs are given to illustrate the influence of the various parameters on the manifested flow behavior.

Journal ArticleDOI
TL;DR: In this article, the effect of urbanization on 24 years of annual flood peaks for a Louisville, Kentucky, watershed was analyzed and it was found that urbanization increased the central tendency, but not the dispersion of the peaks.
Abstract: . In urban hydrologic studies, it is often necessary to determine the effect of changes in urban land use patterns on such runoff characteristics as flood peaks and flow volumes. Nonparametric statistical methods have certain properties that make them a valuable tool for detecting hydrologic change caused by a treatment, such as urbanization, that changes watershed over a period of time. As many hydrologists do not have a working familiarity with nonparametric methods, a number of them are used for illustrative purposes to analyze the effect of urbanization on 24 years of annual flood peaks for a Louisville, Kentucky, watershed. In the example, urbanization was found to increase the central tendency, but not the dispersion of the peaks. Peak flows modeled by holding watershed parameters constant were also found to be increasing because of an upward trend in precipitation. By following the numerical examples in the paper and looking up test statistics in referenced sources, the reader can easily apply these methods to other situations.

Journal ArticleDOI
TL;DR: In this article, studies of the effects of harvesting on hydrophytes in Lake Mendota, Wisconsin indicate that one harvest reduced growth by at least 50%, two harvests reduced it by 75% and three harvest virtually eliminated plant material for the year.
Abstract: Studies of the effects of harvesting on hydrophytes in Lake Mendota, Wisconsin indicate that one harvest reduced growth by at least 50%, two harvests reduced it by 75% and three harvests virtually eliminated plant material for the year. The studies also indicated that harvesting one year reduced the biomass the following year, especially in deep water. Three harvests during the previous year were most effective in controlling biomass the second year.

Journal ArticleDOI
TL;DR: In this article, two computer programs developed at the U.S. Army Corps of Engineers Hydrologic Engineering Center were utilized with modifications to simulate the operation of Folsom Reservoir in central California.
Abstract: : In the last decade, much research has been devoted to applying the systems analysis approach to water resources problems. A popular research goal has been determination of the 'best' method of operating a multipurpose reservoir. The goal of this study was to derive the economically optimum flood control diagram for a multipurpose reservoir by systems analysis. The technique employed to optimize the flood control diagram was programmed so that the optimization process could be applied to other multipurpose reservoirs. Two computer programs developed at the U.S. Army Corps of Engineers Hydrologic Engineering Center were utilized with modifications to simulate the operation of Folsom Reservoir in central California. Economic analyses were incorporated along with an optimization technique into the reservoir operations program; and the resultant program was capable of routing a sequence of monthly reservoir inflows, computing benefits for various flood control diagrams (as dictated by the optimization procedure) and selecting the economically optimum flood control diagram. The univariate gradient technique was the optimization procedure employed. The two computer programs are on file at The Hydrologic Engineering Center in Davis, California. (Author)

Journal ArticleDOI
TL;DR: In this article, the authors present methods of project evaluation and then describe an approach adapted from highway planning literature for evaluating both monetary and non-monetary variables and presenting them to decision makers at all levels.
Abstract: . Decisions among water resources planning alternatives must consider, along with engineering and economics, a variety of environmental and social effects which are viewed and weighted differently by different interest groups. This paper briefly discusses present methods of project evaluation and then describes an approach adapted from highway planning literature for evaluating both monetary and non-monetary variables and presenting them to decision makers at all levels. Social and environmental consequences are analyzed and presented using a graphical description called a “factor profile,” which measures in appropriate units all relevant non-monetary effects of each alternative. Then, using the factor profile and engineering-economic analysis, a series of paired comparisons are made to obtain a preference ranking among alternatives. Since preference decisions are extremely complex, a step by step procedure to simplify the decision-making process is described. A case example considering four proposed flood control alternatives with the relevant environmental and social impacts is given to illustrate the use of the factor profile and the decision making procedure.


Journal ArticleDOI
TL;DR: The Truckee River heads in the Sierra Nevada at Lake Tahoe, and terminates in Pyramid Lake as discussed by the authors, and during the 1969 water year, flow about 9 miles upstream from the mouth (974,000 acre-ft) was almost four times the long-term average, due mainly to heavy winter rains and spring snowmelt.
Abstract: The Truckee River heads in the Sierra Nevada at Lake Tahoe, and terminates in Pyramid Lake. During the 1969 water year, flow about 9 miles upstream from the mouth (974,000 acre-ft) was almost four times the long-term average, due mainly to heavy winter rains and spring snowmelt. A short period of low-altitude rainfall produced the highest concentrations of suspended sediment, whereas a much longer subsequent period of snowmelt yielded a much greater total quantity of material. The upper 90 percent of the basin yielded about 260 acre-feet (630,000 tons) of sediment at the Nixon gage, whereas an estimated 2,800 acre-feet (6.8 million tons) was contributed by erosion of about 200 acres of river bank below the gage. Solute content at the gage ranged from 80 to 450 mg/l, dominated by calcium, sodium, and bicarbonate, plus silica in the most dilute snowmelt and chloride in the most concentrated low flows. Solute load totaled about 130,000 tons, of which the principal constituents in Pyramid Lake-sodium plus equivalent bicarbonate and chloride-amounted to almost 40,000 tons. The total solute load during a year of average flow may be 45,000-55,000 tons, including 18,000-22,000 tons of principal lake constituents.

Journal ArticleDOI
TL;DR: In this paper, an analysis of more than 200 overland flow hydrographs generated by simulated rainfall on long impermeable planes showed that kinematic waves prevailed over dynamic waves.
Abstract: An analysis of more than 200 overland flow hydrographs generated by simulated rainfall on long impermeable planes showed that kinematic waves prevailed over dynamic waves. Although laminar flow appears to occur at low flows, most flows appear to be either in the transition from the laminar to the turbulent state or in a fully developed turbulent state. Location of the laminar-turbulent transition could not be explained in terms of Reynolds number alone. The transition was significantly affected by rainfall intensity-a factor which rendered quantification of the transition indeterminate. However, the error involved in treating all flows as turbulent would be small with the resulting analysis made considerably less complex.

Journal ArticleDOI
TL;DR: In the early part of the First Millenium B.C. as mentioned in this paper, a kind of infiltration gallery was invented for obtaining groundwater without the use of wells or sweeps, which is still widely used in the Mediterranean area, southwest Asia and China.
Abstract: Present-day climatic conditions of the Earth were reached between 5,000 and 8,000 years ago. These are essentially the conditions under which the earliest civilizations arose. Ancient basic water problems were the same as those of today, and remarkable technologies for coping with these problems were developed. Few water technologies, except for water treatment, are modern creations. Dry farming began about 8000 B.C. Irrigation began about 5000 B.C. and became extensive by about 3500 B.C., principally in Mesopotamia, the Nile Valley of Egypt, and the Indus Valley of Pakistan. Ancient irrigators developed ingenious structures for obtaining groundwater without the use of wells or sweeps. One device, the Khanat (a kind of infiltration gallery), is still widely used in the Mediterranean area, southwest Asia and China. The khanat was invented during the First Millenium B.C. Ancient peoples also learned to collect surface runoff in areas of scanty precipitation and to use it for local groundwater recharge. The water was recovered from dug wells and used for domestic supply and stock watering. Damming of rivers began at least by the early part of the First Millenium B.C. in the Arabian Peninsula. Most early dams were for irrigation but some were also for city water supply. Many canals in various areas served the dual purposes of water supply and navigation. Soil and water salinity have been persistent problems throughout the history of irrigation and we still have not solved these problems. Irrigation practices were developed independently in the New World but much later than in the Old. North American Indians in some areas still follow the ancient practices. The chinampa system, still used in Mexico, is one of the most intensive methods of farming ever devised. Ancient peoples in the Old World also developed ingenious methods for conserving and increasing soil moisture and for retarding runoff and erosion. During the time of classical Greece and imperial Rome practical water engineering developed to a high degree. Water tunnels, aqueducts, canals, drainage ditches, and dams become commonplace. Even so, water supply and management came relatively late in Europe, where dependence had been largely on natural supply and distribution until the 19th Century.


Journal ArticleDOI
TL;DR: In this paper, a scheduling model was developed to improve the management of irrigation systems, and water application decisions incorporated climatological records, soil-plant data, current pan evaporation and rainfall, the number of fields to be irrigated, and 5-day weather forecasts.
Abstract: In humid areas appreciable amounts of rainfall complicate irrigation scheduling. This rainfall tends to give supplemental water application a low priority. As a result irrigation may be delayed until there is not enough time to cover the crop area before some drought damage occurs. To improve the management of irrigation systems, a scheduling model has been developed. The model's water application decisions incorporate climatological records, soil-plant data, current pan evaporation and rainfall, the number of fields to be irrigated, and 5-day weather forecasts. The model updates the soil moisture conditions, predicts impending water depletion, and if supplemental water is needed both the field priority and amount to be applied is indicated for each of the next 5 days. Errors introduced through the use of forecasts and long-term pan evaporation records have been slight because of the tri-weekly updating. Also natural rains which restore the root zone to maximum water holding capacity prevent long-term bias.

Journal ArticleDOI
TL;DR: In this article, the authors present the elements of a rural water supply program and the difference between rural and urban supplies in such areas as community participation, financing, technical assistance, etc.
Abstract: The best available figures indicate that on a global basis only about 10 per cent of the rural populations have a safe source of water, with the Region of the Americas having the highest coverage at 19 per cent. The program of the Second U.N. Decade proposed to supply coverage to about 200 million persons at an estimated cost of 1.6 billion dollars by 1980. The elements of a rural water supply program are presented, then the difference between rural and urban supplies in such areas as community participation, financing, technical assistance, etc., are discussed. The use of revolving funds to help finance this effort, and the use of the mass approach to help the governments increase their program coverage, are also presented. This paper concludes that while much has been done in the 60's, much remains to be done, but that the basic tools for this effort are available.

Journal ArticleDOI
TL;DR: A review of the main investigations in this field is summarized in this article, which is subdivided into three main eras: (1) The period through which the problems were identified and field observations were explained (from 1855 until the early forties); (2) the analytic approaches during the period from 1940 to the late sixties; and (3) the refined techniques during the past three years.
Abstract: Almost thirty years after the first known publication on salt water problems published in 1855 by Braithwaite, two investigators developed an approximate theory to find the boundaries of fresh water lenses in coastal aquifers. Their theory is now known as Ghyben-Herzberg Theory. Although their theory is based on oversimplified assumptions, it has stimulated others through various periods of time. A review of the main investigations in this field is summarized in this paper. The discussions are subdivided into three main eras: (1) The period through which the problems were identified and field observations were explained (from 1855 until the early forties); (2) the analytic approaches during the period from 1940 to the late sixties; and (3) the refined techniques during the past three years. A brief summary of the recharge methods is also given in addition to a more or less comprehensive list of references.

Journal ArticleDOI
TL;DR: In this paper, the authors extended the applicability of an algorithm that had been previously applied to the deterministic river-basin expansion problem to include the feature of a sensitivity analysis.
Abstract: . Individuals and organizations concerned with the expansion of the facilities of a river basin (such as a river basin authority) need to determine optimal strategies of operation and capital investment. They also need to examine the sensitivity of whatever planning decisions are contemplated. This paper extends the applicability of an algorithm that had been previously applied to the deterministic river-basin expansion problem to include the feature of a sensitivity analysis. The algorithm, containing a partial enumeration search technique and a network analysis code, gave a construction sequence of reservoirs, canals, and treatment plants, and an operating policy that maximized the present value of net earnings consistent with certain underlying assumptions. A river basin was chosen that had an existing configuration of unregulated streams and rivers, reservoirs, canals and treatment plants, and sites for future additional facilities. A series of representative synthetic flow sequences, future demand profiles, interest rates and reservoir costs that served as inputs to or parameters in the system were each perturbed by various factors (for a total of 24 cases). The sensitivity studies showed that the immediate planning decision of what facility to construct next was insensitive to variations in future demands and costs and independent of later decisions. Thus, decision-making was adaptive in the sense that by always making the optimal proximate decision, the management of the river basin is optimized.

Journal ArticleDOI
TL;DR: This article evaluated the social-psychological response of local residents to the forced relocation and subsequent disruptive effects of the resettlement and found that the affected community groups were not significantly different in terms of alienation from the non-affected base groups.
Abstract: . Construction of water impoundment projects often necessitates relocation of numerous rural residents which can result in social disruption of established interaction patterns within affected groups. A research study was conducted within two communities in West Virginia and two communities in Ohio which had recently been subjected to watershed development. The objective of the research was to evaluate the social-psychological response of local residents to the forced relocation and subsequent disruptive effects of the resettlement. The dependent variable used in the research was community alienation. The findings revealed that the affected community groups were not significantly different in terms of alienation from the non-affected base groups. This finding suggests that forced relocation did not consistently lead to personal alienation from the changed community. It was noted, however, that negative attitudes were identifiable among the affected community members but the negative comments appeared to be directed toward the change agency and toward physical relocation rather than the community per se.

Journal ArticleDOI
TL;DR: In this paper, the authors specify the necessary conditions for survival of an irrigated agriculture in terms of a positive net income in each subplanning period discounted to its present value.
Abstract: Salinization and water logging have been the nemesis of irrigated agriculture societies since Babylonian times Low quality water substitutes for high quality water for irrigation at an increasing rate up to the limits of the soil's ability to transmit the additional water and remove excess salts from the root zone Soil transmissibility can be increased by additional investment in drainage ditches and underground tile Low valued-high salt tolerant crops can be substituted for higher valued-salt sensitive crops to maintain production in areas served by irrigation water sources of deteriorating quality Thus physical factors specify the necessary conditions for survival of an irrigated agriculture The sufficient conditions for survival must be in terms of a positive net income in each subplanning period discounted to its present value

Journal ArticleDOI
TL;DR: In this paper, the X-ray fluorescence method was used to analyze trace metals collected in particulate form on filter papers and from the ionic state by ion exchange filter papers.
Abstract: . The X-ray fluorescence method was used to analyze trace metals collected in particulate form on filter papers and from the ionic state by ion exchange filter papers. The samples were prepared by allowing water to pass through these filter papers. The procedures necessary for using the X-ray fluorescence method are described. A number of samples were taken from the Great Miami River in Dayton, Ohio over one year showing the presence of the following metals, Ca, Ti, Cr, Fe, Cu, Zn, Sr, and Cd. Elements in the periodic table between Ti and Cs were detectable to a sensitivity limit of the order of 30 ppb for metals in the particulate form and 0.4 ppm for metals in the ionic form.