ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05131.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05132.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTEconomics of treatment plant staging or capacity expansions is governed by the initial water demand rate, Q0; the anticipated demand growth rate, G; the discount rate, D; the cost of operation, maintenance, and repair (OMR); the useful plant life, T, as a function of the quality of design, construction, and OMR; the treatment plant load factor, Lf; the salvage value of the plant at the end of the project period; the efficiency of the plant‐staging design, eta; and the length of the project period, Ts. Various staging policies are investigated to find an optimal policy. The desirability of adopting a staging policy is governed by the magnitude of percent savings that can be achieved by adopting this policy instead of a no‐staging policy. A detailed analysis of the problem shows that the percent savings because of staging increase with an increase in Q, G, D, T, and eta;. A reduction in the plant load factor increases the total costs. Information about the effect of variation in the parameters should help the planner and designer to work out an economical schedule of treatment plant capacity expansi

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05133.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTDeep within the earth there exist immense reservoirs of energy in the form of heat‐commonly referred to as geothermal resources. Unfortunately, most of these resources are at such depths that it is unlikely they will be recoverable in the foreseeable future. Nevertheless, the lure of seemingly inexhaustible amounts of relatively clean energy continues to hold a fascination for man. In certain limited situations man has already been able to tap these reservoirs and harness the energy to his own uses. More of this activity can be expected in the future. While geothermal energy will chiefly be used to produce electric power, persons responsible for water resources management must concern themselves with geothermal resources for water, and water law concepts will continue to play an important role in the development of this resourc

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05134.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTThis paper suggests a number of benefits in identifying urban and regional planners as a public in public participation programs of water resources planning studies. A perspective on public participation is presented. Recent trends and developing concepts are identified: emphasis on the need to coordinate urban and regional planning activities with water resources planning, increasing system complexity, the goals and objectives orientation of planning, planning for multi‐objectives, the evaluation of a broader range of alternatives, and the consideration of water alternatives as only one set of measures to further society's aspirations. One way to assist in capitalizing on these trends is to seek out participation of those in other planning efforts who are involved in planning but on a different level. Because of their intimate knowledge of an areas history, growth and development, political climate, local perceptions of needs and desires, and major problems and issues they are able to contribute a great deal of insight in making the water resources planning effort more responsive at the local level. The paper describes one of the first major efforts at working‐level public‐planner contact which was carried out as part of the Susquehanna River Basin Study. A regional survey team comprised of an engineer and an economist from a federal agency and a state water resources planner met informally with planners, city managers, and local planning commissions to discuss issues related to water resources and the growth and development of local areas. This effort while only part of the overall public participation program yielded a number of benefits and if expanded and refined would be a very useful experience in other st

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05135.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTThe 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 behav

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05136.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTAlmost 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 reference

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05137.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTConfined flow toward a single well of finite radius in an extensive aquifer of uniform transmissibility is studied under the assumption of time‐dependent drawdown.Three particular cases are considered: (a) linear drawdown (including constant drawdown); (b) exponential drawdown; (c) periodic (sinusoidal) drawdown.The differential equation governing unsteady axial symmetric flow toward a single well in a confined aquifer is solved for the three different situations by the use of the Laplace transform method. The resulting expressions are integrated by adapting a modified Gemant scheme.General computer programs have been developed and operated for several combinations of characteristics. The results are plotted to show the effect of time dependent drawdown on the variation of the well discharge and the piezometric head distributio

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05138.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTThe use of linear programming as a planning tool for determining the optimal long‐range development of an urban water supply system was explored. A stochastic trace of water demand was synthesized and used as an input to the model. This permitted evaluating the feasibility of imposing demand restrictions as an effective cost reduction mechanism. The City of Lincoln, Nebraska, was used as the urban model. The fundamental problem was to allocate limited water supplies from several sources to an urban load center to minimize costs and comply with system constraints. The study period covered twenty years, and findings indicate the planning direction for stage development during this period. Sensitivity analyses were performed on cost coefficients and demands. Thirteen sources were included in the initial computations. Conclusions were that linear programming and generated demand traces are useful tools for both short‐ and long‐term urban water supply planning. Lowering peak demands results in long‐range development of fewer sources of supply and more economic and efficient use of the supplies de

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05139.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACTWithin a few years all domestic wastewater effluents in the United States will be subjected to a minimum of a properly operated primary and secondary treatment process. This implies a very high degree of removal of the more readily biologically degradable material as measured by the BOD test. This practice will to a large degree negate the value of the BOD test as a pollution parameter. Organic carbon appears to be a more suitable means for determining the strength of a wastewater or for controlling the operation of physical and chemical treatment processes. Studies were conducted to determine the effect of time of passage on the ratio of organic carbon to BOD, COD and carbohydrate. The ratio was found to vary with both time and the state of the sample. The carbon content was reduced to a lesser degree than the other parameters. Organic carbon content appears to correlate better with COD than with BOD. The efficiency of a chemical precipitation process can be determined on the basis of organic carbon removal.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05140.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY