William J. Grenney

A graphical technique for river water temperature predictions

Abstract Water temperature is one of the more important parameters affecting the suitability of streams as a fish habitat. The average equilibrium temperature is a useful concept because it is the temperature about which the instantaneous temperature tends to oscillate. The technique presented in this paper provides a straightforward graphical means for estimating the equilibrium temperature and thermal exchange coefficient on the basis of meteorological conditions including solar radiation, cloud cover, air temperature, wind speed, relative humidity and atmospheric pressure. The technique may also be used to calibrate coefficients for a specific stream and to predict water temperature for a variety of flow alterations and thermal loadings. The technique may be programmed on a programmable calculator using the equations developed in the paper.

Decision support model for hazardous waste application rates at land treatment systems

Abstract A mathematical model is described which provides a rational approach for obtaining, organizing and evaluating the specific information needed for the determination of hazardous waste application on land treatment systems. The model is divided into five modules. These modules represent the principal mechanisms which are assumed to govern the fate of an organic hazardous material in the vadose zone. They are the following: loading conditions, degradation, advective transport, dispersive transport and sorption/desorption. The numerical algorithm for advective transport is described in some detail using a soil-water system as an example. The model is demonstrated for selected aro-matics found in a refinery waste sludge. Application of the model provides a methodology for predicting the behavior of hazardous constituents in soil systems and ranking chemicals according to their need to be controlled.

An atmospheric—terrestrial heavy metal transport model. I. model theory

Abstract A general model TOHM was developed to predict the terrestrial fate of zinc, cadmium, chromium, lead and mercury emitted by the operation of a coal-fired electric generating facility. The general model consisted of interfacing submodels describing atmospheric dispersion, precipitation, soil chemistry, and soil erosion. The models were developed from input data from a semi-arid region of the southwest United States, and except for the climatic and topographic constraints, are not site specific. TOHM was found to predict no substantial increase in indigenous levels of zinc, chromium and lead in the impact (deposition) area. However, both mercury and cadmium were predicted to be emitted and eroded to the environmental sink (receiving lake) in concentrations exceeding that naturally present in the system. TOHM is currently unvalidated, though comparison of soil erosion predictions with erosion quantities measured in the impact area gives good agreement.

Fugacity Framework: Web Access And Implementation For Site Assessment And Rehabilitation

The fugacity-framework addresses multiple-media and multiple contaminant aspects of environmental site assessment. A U.S. EPA database of priority chemicals has been linked to the fugacity model for assessment of contaminant sources, transport and transformation, and exposure. Site-specific data are provided by the user. This tool provides a way for managers to visualize the behavior of toxic chemicals at a contaminated site, the effect of site-specific characteristics on contaminant distribution, the behavior of daughter products of degradation, and the associated risks to humans and the environment. The framework can be used to make decisions regarding protection of public health and the environment, site rehabilitation, and the sustainable development and economic recovery of impacted sites, The fugacity framework can be accessed at http://www,engineering .usu.eduluwrY, Utah Water Research Laboratory.

A C++ Class for Rule-Base Objects

A C++ class, called Tripod, was created as a tool to assist with the development of rule-base decision support systems. The Tripod class contains data structures for the rule-base and member functions for operating on the data. The rule-base is defined by three ASCII files. These files are translated by a preprocessor into a single file that is located when a rule-base object is instantiated. The Tripod class was tested as part of a proto-type decision support system (DSS) for winter highway maintenance in the Intermountain West. The DSS is composed of two principal modules: the main program, called the wrapper, and a Tripod rule-base object. The wrapper is a procedural module that interfaces with remote sensors and an external meterological database. The rule-base contains the logic for advising an inexperienced user and for assisting with the decision making process.

An atmospheric—terrestrial heavy metal transport model. II. Process equations

Abstract The process equations used by Wagenet et al. (1978) to describe the atmospheric— terrestrial transport of heavy metals are presented in detail. The accounting procedures allowing calculation of sediment eroded, heavy metal distribution, soil chemical reactions and precipitation are explained. The process equations for the atmospheric dispersion model of Wagenet et al. (1978) are not included.

Reservoir Destratification by Withdrawal from the Hypolimnion1

This paper reports on the development and applications of a computer model to evaluate temperature destratification in a small reservoir by selective withdrawal. A reservoirs temperature model was developed to calculate the temperature profile and the stability index of a small reservoir. The model was developed to make the most efficient use of available meteorological and flow data. The model was applied to estimate the changes in reservoir stratification that would result from various withdrawal patterns. The model results indicate thermal stability could be reduced by 75% during mid-summer by selective withdrawal.