摘要:

ABSTRACT:A nonlinear hydrologic system model has been developed for analyzing the urban rainfall‐runoff process. The model is formulated as a state variable model consisting of several parameters. A search technique is employed to find the set of parameters for which the model's response best fits observed data. The model could be used in either a simulation or forecasting mode. The model is applied to observed data for the Waller Creek Watershed in Austin, Texas, to develop the model parameters for various levels of urbanization of the watershed. The trend of each parameter with respect to levels of urbanization is examine

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1981.tb03920.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACT:Waste waters from various operations at the Miami International Airport are characterized. Servicing, maintenance, overhauling, and washing of aircraft seem to be the most significant waste water producing operations. Pollutional constitutents commonly found in the airport wastes include acids, alkalis, detergents, oil, grease, and oxygen demanding substances. Phenols are of concern when stripping and repainting operations occur. Although most airport wastes may be treatable, a great reduction in influent load can be achieved by proper housekeeping methods.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1981.tb03921.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACT:In flood frequency analysis it is required to estimate the values of probabilities based on plotting formula. All of the many existing formula provide different results, particularly at the tails of the distribution. The existing practice in selection of a particular formula is rather arbitrary; and often Weibull's formula is recommended, which provided biased and conservative results. Based on the mean square criterion, a new plotting formula is developed, and it is given by Fm= (m ‐ 0.24)/(N + 0.5

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1981.tb03922.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACT:Urban runoff as well as industrial and agricultural discharges have seriously affected the water quality of the Skudai River, Malaysia. A water quality model is developed for simulating BOD and oxygen relationship. The simulated values agree relatively well with survey data taken during low flow conditions. Survey and simulated values show that a pollution abatement program is needed to prevent further deterioration of the river from organic discharges. A systems approach, involving complete analysis of water quality models and environmental control procedures, considering various water use patterns, water quality criteria, and waste input, is essential for solution.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1981.tb03923.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACT:The paper presents a conceptual procedure for developing a design storm hydrograph. The methods were developed by conducting a regression analysis with simulated data generated by a complex computer model. A brief description of the model is presented together with the results of a verification study with the model. The model is based on SCS procedures but also incorporates a double triangle hydrograph method for use in agricultural and forested water‐sheds. The regression procedures provide a simple hand calculator method for generating a storm hydrograp

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1981.tb03924.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACT:Varying treatment levels to meet seasonal variation in assimilative capacity of streams can reduce total costs of treatment. A mathematical model of a Pennsylvania stream based on a theoretically sound approximation of the physical relationships underlying the distribution of DO in a river system was used to determine discharge constraints for an economic optimization model which produced estimates of sewage treatment cost savings. Increasing the number of flow periods during the year enhances cost reducing opportunities even when land application processes are considered. Also, the least cost treatment process for year around operation may not be the least costly under multiple flow period management.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1981.tb03925.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACT:Urban storm water data from four catchments near Miami, Florida, were collected and compiled by the U.S. Geological Survey and were used for testing the applicability of deterministic modeling for characterizing storm water flows from small land use areas. The four sites were:(1) a 40.8‐acre (0.165‐km2) single family residential area(2) a 58.3‐acre (0.236‐km2) highway area(3) a 20.4‐acre (0.083‐km2) commercial area, and(4) a 14.7‐acre (0.059‐km2) multifamily residential area.A distributed routing rainfall‐runoff model was used to simulate 328 storms at one‐minute time intervals. Weighted Standard Error of Estimates (SEE) for storm runoff volume for calibration and verification simulations were 0.072 in. (1.829 mm) and 0.117 in. (2.972 mm), respectively, while the corresponding SEE for peak discharges were 5.761 cfs (0.163 m3/s) and 5.119 cfs (0.145

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1981.tb03926.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACT:Water quality was monitored for 17 months during base flow periods in six agricultural watersheds to evaluate the impact of riparian vegetation on suspended solids and nutrient concentrations. In areas without riparian vegetation, both instream algal production and seasonal low flows appeared to be major determinants of suspended solids, turbidity, and phosphorus concentrations. Peak levels of all parameters were reached during the summer when flows were reduced and benthic algal production was high. Similar summer peaks were reached in streams receiving major point inputs but peaks occurred downstream from the input. Instream organic production was less important in regulating water quality in areas with riparian vegetation and permanent flows. Concentrations of suspended solids remained relatively constant, while phosphorus and turbidity increased in association with leaf fall in autumn. Intermittent flow conditions in summer increased the importance of instream organic production in controlling water quality, even when riparian vegetation was present. Efforts to improve water quality in agricultural watersheds during base flow should emphasize maintenance of riparian vegetation and stable flow conditions.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1981.tb03927.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACT:Numbers and record lengths of precipitation stations were surveyed in the conterminous United States using climatological data published in 1975 by the National Weather Service (NWS). The total numbers of nonrecording (8247) and recording (3036) gages were about the same as in the 1940s and less than in the late 1950s; about 70 percent of the nonrecording gages have record lengths of 25 years or more. State network densities were increased exponentially with population density and long term precipitation average. Except for a few states, precipitation stations maintained by the NWS are adequate in numbers to ensure a 95 percent statistical probability that state sample means will estimate true means within ± 5 percent

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1981.tb03928.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACT:A survey of 34 open hand dug wells was performed in the Senegal River basin of West Africa. Nitrate concentrations were determined on the well water samples over a six‐month period. With the exception of two wells, the wells indicated varying levels of nitrate contamination. The range of concentrations was 0.10 to 880 mg/I as nitrate. These data when compared to physical characteristics, land use, and age using a chi‐square analysis did not suggest any strong association. The fact that these wells are open and in a semiarid climate may be of such importance that the previously considered factors are of minor relative importance. Contamination may be primarily the result of foreign matter entering the well mo

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1981.tb03929.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY