摘要:

ABSTRACT:ABSTRACT: The National Water Data Exchange (NAWDEX) was implemented in January 1976 as an interagency program managed and coordinated by the U.S. Geological Survey. The program is directed at improving access to existing water and water‐related data. Almost 150 organizations from the Federal, state‐governmental, local‐governmental, interstate, academic, private, and foreign sectors currently participate in the program. This article describes the NAWDEX program and contains descriptions of the types of data and services available from organizations participating in NAWDEX. A point of contact for obtaining data and services is provided for each organiz

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1980.tb02324.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACT:While the quality of rivers has received much attention, the degradation of small streams in upland areas of watersheds has only recently been recognized as a major problem. A major cause of the problem is increases in nonpoint source pollution that accompany urban expansion. A case study is used to examine the potential for storm water detention as a means of controlling water quality in streams of small watersheds. The storm water management basin, which is frequently used to control increases in discharge rates, can also be used to reduce the level of pollutants in inflow to receiving streams. Data collected on a 148‐acre site in Maryland shows that a detention basin can trap as much as 98 percent of the pollutant in the inflow. For the 11 water quality parameters, most showed reductions of at least 60 percent, depending on storm characteristic

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1980.tb02325.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACT:Sliding polynomials differ from other piecewise interpolation and smoothing methods in their functional continuity at the nodes. This functional continuity was used to establish optional spacing of nodes and optional boundary controls in data smoothing while still maintaining mathematically continuous rates or gradients. Cyclic as well as noncyclic data can be smoothed. Variance of the individual nodal values. derived through least‐squares optimization, can be calculated using the rigorously determined weighting coefficients between data points and nodes. Such nodal variances are estimates of localized uncertainty in the data which complement the localization of smoothing through use of piecewise functions. Choice of controls in smoothing and calculation of variance have been incorporated in a computer program for user convenienc

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1980.tb02326.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACT:The traditional “requirements” approach to water system planning presumes perfectly inelastic demand and arbitrarily selects a fixed water requirement per capita per day as a planning target. Economists have often pointed out that such a policy leads to over‐investment in water supply facilities; a superior approach would maximize some measure of net benefits incorporating price‐sensitive demand. Using a dynamic programming model to depict an investment problem in Rhode Island, we find that ambiguities about how to incorporate price‐sensitive demand into a decision framework may make such an approach as arbitrary as the requirements approach. Water conservation responses may be a function of other social parameters than water price; if so, variations in these social parameters should be regarded as economic alternatives to water supply in

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1980.tb02327.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACT:The proper use of input‐output for estimating regional benefits and costs is described for instances where project outputs go to final or intermediate demand. How that estimation is affected by the method used to value the primary project benefits and by the sector content of the input‐output model compared to the primary sector affected are discussed as are points of terminological confusion between the two meth

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1980.tb02328.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACT:This study determined the acute toxicity of waste water disinfected with chlorine, bromine chloride, or ozone. The residual toxicity of effluent dechlorinated with sulfur dioxide was also tested. Toxicity tests were conducted with cyprinid, salmonid, and centrarchid fishes, as well as several species of fresh water macroinvertebrates. Residual chlorine exhibited the greatest toxicity of the disinfectants tested; dechlorination with sulfur dioxide effectively eliminated the toxicity of chlorinated effluent. Residual ozone produced mortality in test animals only under special conditions where subjects were exposed to effluent immediately after it was contacted with ozone, and chlorobrominated effluent was more toxic to salmonids than chlorinated effluent.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1980.tb02329.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACT:With the increased use of models in hydrologic design, there is an immediate need for a comprehensive comparison of hydrologic models, especially those intended for use at ungaged locations (i.e., where measured data are either not available or inadequate for model calibration). But some past comparisons of hydrologic models have used the same data base for both calibration and testing of the different models or implied that the results of model calibration are indicative of the accuracy at ungaged locations. This practice was examined using both the regression equation approach to peak discharge estimation and a unit hydrograph model that was intended for use in urban areas. The results suggested that the lack of data independence in the calibration and testing of regression equations may lead to both biased results and misleading statements about prediction accuracy. Additionally, although split‐sample testing is recognized as desirable, the split‐samples should be selected using a systematic‐random sampling scheme, rather than random sampling, because random sampling with small samples may lead to a testing sample that is not representative of the population. A systematic‐random sampling technique should lead to more valid conclusions about model reliability. For models like a unit hydrograph model, which are more complex and for which calibration is a more involved process, data independence is not as critical because the data fitting error variation is not as dominant as the error variation due to the calibration process and the inability of the model structure to conform with data vari

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1980.tb02330.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACT:Recognition of the flood hazard that exists on alluvial fans has seriously lagged behind the recognition of other more conventional flood hazards such as those associated with most rivers. This delay in recognition was due, until recently, to a general lack of economic investment and development in these areas and a concomitant lack of historical alluvial fan flood damage. Dramatic recent events, such as Tropical Storm Kathleen, emphasized to the Federal Insurance Administration (FIA) the need for developing an appropriate methodology to identify flood hazard areas on alluvial fans. This paper presents the methodology now employed by FIA as well as flood plain management considerations that could reduce future flood related damage to communities developing in these areas.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1980.tb02331.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACT:A combination pumped storage reservoir system was simulated by modifying the WRE deep reservoir model. Each of the two reservoirs was described by a copy of the WRE model program, the two programs were converted into subroutines and were called upon alternately by a main program. Operationally, the contributing reservoir, i.e., the reservoir from which flow was discharged, was simulated for one execution interval (1 hour), followed by simulating the receiving reservoir for the same execution interval. The main program directed the discharge temperature of the contributing reservoir for each execution interval as input for simulating the receiving reservoir. The two subroutines were run in this interactive mode for a simulation period of one year.Two simulations, labeled “Pump” and “Net,” were effected and differed basically in the distribution of flow volumes exchanged between the reservoirs. In the ‘Pump’ simulation the total hourly flow volumes were distributed into appropriate horizontal layers of the lakes as determined by temperature‐density relationships, i.e., the pumped discharges were distributed into the upper lake and the generation discharges were distributed into the lower lake. In the ‘Net’ simulation only the net daily discharges (daily difference between pump‐back and generation at the upper dam), distributed uniformly over 24 hours, were mixed into the horizontal layers of the two lakes.Both simulations produced annual thermal regimes that were apparently within reason for the geographical area and the nature of the input data. However, neither accurately reflected a generalized conditions for the reservoirs because the Pump simulation reflected conditions in the forebay and tailrace of the Upper dam while the Net simulation reflected conditions of the remaining part

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1980.tb02332.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACT:Planning for urban drainage and flood control requires the use of a rational procedure for setting priorities and allocating funds. An innovative procedure developed by the Los Angeles County Flood Control District is described. It consists of the use of bond election voting results as a surrogate for demand signals representing the public preference for project approval. A regression equation has been developed to relate project characteristics to the likelihood of approval. The procedure is implemented through a “funnel‐screen” review procedure which results in a list of reviewed and approved pro

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1980.tb02333.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY