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Full-Text Articles in Engineering

Mixed Integer Programming Models For Water Resources Management, Brad A. Finney, William J. Grenney, A. Bruce Bishop, Trevor C. Hughes Jan 1977

Mixed Integer Programming Models For Water Resources Management, Brad A. Finney, William J. Grenney, A. Bruce Bishop, Trevor C. Hughes

Reports

A regional water quality control model is developed by linking a steady-state water quality simulation model with an optimization model. The water quality simulation model can be applied to complex river systems with both point and nonpoint loads using multiple interdependent pollution parameters described by either linear or nonlinear equations. Twelve water quality parameters can be modeled simultaneously: four non conservative constituents (or conservative constituents if the decay rate is set equal to zero); coliform bacteria (MPN); phosphorus; biochemical oxygen demand (BOD); ammonia (NH3); nitrate (NO3); dissolved oxygen (DO); temperature (°C); and algae. The water quality model is used to …


Estimation Theory Applied To River Water Quality Modeling, David S. Bowles, William J. Grenney, J. Paul Riley Jan 1977

Estimation Theory Applied To River Water Quality Modeling, David S. Bowles, William J. Grenney, J. Paul Riley

Reports

The extended Kalman filter (EKF) is used to represent BOD, DO, and nitrogen cycling in a 36.4 miles (58.6 km) stretch in the Jordan River, Utah, under the assumption of steady-state conditions. Approximate minimum variance estimates of the water quality parameters are provided by the EKF filter. These estimates are obtained through a combination of two independent estimates of the state of the river water quality system: (1) predictions of the system state from a "phenomenologically meaningful" process model of the biochemical and stream transport processes; and (2) measurements of the water quality parameters. These two estimates are combined by …


Rural Domestic Water System Peak Flows And Design Innovations, Optimal Water Planning Series, Trevor C. Hughes, Yukio Kono, Ronald Canfield Jan 1977

Rural Domestic Water System Peak Flows And Design Innovations, Optimal Water Planning Series, Trevor C. Hughes, Yukio Kono, Ronald Canfield

Reports

Planning engineers commonly use generous factors of safety for peak flow estimates in urban water supply systems both as a hedge against unforeseen growth and because economies of scale result in relatively low user costs even with such reserve capacity. Transplanting of such design criteria into the rural setting, however, simply does not work. The low density portions of rural domestic systems require very realistic design criteria or the construction costs become infeasible for the small number of customers involved. Peak instantaneous flow rates in a Utah rural system were measured continuously during two summers on three dead-end lines serving …


Climatology Of Hailstorms In Utah--The Hail Suppression Potential By Cloud Seeding, Kenneth G. Hubbard Jan 1977

Climatology Of Hailstorms In Utah--The Hail Suppression Potential By Cloud Seeding, Kenneth G. Hubbard

Reports

Hail damage in Utah was examined for individual counties and the entire state. A survey of informal observes was taken and the resulting data base was analyzed. Data from NWS was also examined. County hail damage figures average 4 to 5 percent of production and ranking of counties according to dollar damage occurs in only 4 of the 29 counties (Box Elder, Utah, Millard, and Cache). In many cases the highest dollar damage occurred in the counties of greatest dollar damage should receive the greatest concentration of hail suppression effort. In addition storm severity and crop growth stage were identified …


Weather Modification Studies: The Potential For Creating And Utilizing Ice Crystals In Weather Modification Activities, Kenneth G. Hubbard Jan 1977

Weather Modification Studies: The Potential For Creating And Utilizing Ice Crystals In Weather Modification Activities, Kenneth G. Hubbard

Reports

A method utilizing ice crystals to circumvent nucleation processes in cloud seeding activities is discussed in the framework of nuclei activation concepts. Ice, in the form of small crystals, would be a highly efficient cloud seeding materia up to 0 degrees Celsius. The lower limit on humidity would necessitate dispensing the crystals into air that is saturated with respect to ice but no requirement for 100 percent RH(relative humidity) was found. In fact, the lower limit varies with temperature linearly from about 95 percent RH at -5 degrees Celsius to 75 percent RH at -30 degrees Celsius. Preparation of small …


Evaluation Of Southern And Central Utah Cloud Seeding Program, Geoffrey E. Hill Jan 1977

Evaluation Of Southern And Central Utah Cloud Seeding Program, Geoffrey E. Hill

Reports

An evaluation of a winter operational-type cloud seeding project in Utah is made by developing meteorological predictors of target precipitation. Twenty-four hour precipitation amounts in seven unseeded years are matched with 12:00 GMT rawinsonde data to form predictor-predictand relationships. Application of the predictors to the first two years of the project indicates that the observed seeded precipitation is about what would be found in the absence of seeding.