Continuing expansion and intensification of urban and metropolitan development in semi-arid regions of the Southwest (like Tucson and Phoenix areas) are adding new dimensions to the problems associated with water supply and management. Continual decline in ground water levels and impairment of the ground water quality associated with it have now become a major concern. Urban storm runoff comprises a potentially useful water source for domestic, recreational or other uses. In the semi-arid Southwest, due to generally higher temperatures prevailing in that region and the intermittent nature of rainfall and runoff, a great portion of this source is lost in wetting the ground surface and sand in the channels and through subsequent evaporation before it can substantially contribute to ground water. Storage and utilization of this source will require knowledge about the quality of the water it contains. The present study represents an attempt to determine the quality of water that flows through the city drainageways from different types of areas such as domestic, commercial and industrial. The results of this study are based on the analysis of runoff samples collected during the summer and winter rainy seasons of the year 1969 from three different types of watersheds in Tucson selected by the Water Resources Research Center in association with the Department of Civil Engineering at The University of Arizona. The samples were analyzed for various parameters of pollution and also for usual mineral constituents. The results of the analyses have been discussed and compared with other studies. It was evident that some degree of treatment was needed for future utilization of these waters. This study also attempts to note the effects of simple treatment of aluminum sulphate (alum) on large samples collected from two watersheds. The effects of treatment on turbidity, chemical oxygen demand and densities of bacterial indicators of pollution have only been noted.

An intensive examination was conducted to test the credibility of current traffic signal change interval policies founded on a kinematic equation developed nearly 30 years ago. The investigation involved the review of relevant literature as well as an extensive collection of data. The literature review and data analysis revealed that current change interval policies rely on the disproven assumption that traffic decelerates at a constant rate. The data analysis also demonstrated that traffic approach speed and deceleration distance affect the manner in which deceleration occurs. Based on the data analysis, an alternative treatment of the kinematic equation is proposed using surrogate deceleration rates. The surrogate rates offer a pragmatic set of input for the kinematic equation. Therefore, rather than yielding a change interval based on an inaccurate assumption, agencies can implement change intervals which are responsive to local traffic.

The mixing of the waters of the Salt and Verde Rivers was studied and modeled. The river waters mix for three and one-third miles between their confluence and Granite Reef Dam, where they are diverted into canals. Mixing is frequently incomplete, and as the natural water chemistries differ, the canal water chemistries frequently differ. The mixing of the river waters was modeled mathematically with the use of a two-dimensional form of the convection- dispersion equation. A finite-difference solution of the equation was used in the development of a computer program. The model was calibrated using flow and tracer data collected at a discharge of 1050 c.f.s. from the onethird mile reach immediately below the confluence. The model adequately simulated mixing at the discharge at which data were obtained. Mixing was found to be relatively rapid, requiring an average value of k, the ratio of the dispersion coefficient to the shear velocity and depth, equal to 3.2. Simulation of a higher discharge of 5340 c.f.s., however, required a much lower value of k, 0.6. This difference is assumed to be due to the effects of channel geometry on the rate of dispersion.

This study examines the combined treatment processes of air stripping and activated carbon adsorption for removing carbon tetrachloride, trichloroethylene and 1,4 dichlorobenzene from groundwater. Air stripping was used as a pretreatment with activated carbon as a polishing step. Optimization is achieved by determining the minimum operating and amortization costs for the variables of packing media depth versus carbon usage rate. A simplified design example illustrates the method of determining the optimum combination of treatment processes for the compounds and concentrations examined. The study included laboratory experiments which examined the air stripping performance of two different packing media as well as developing activated carbon isotherms. The transfer unit model was utilized to estimate the overall liquid mass transfer coefficient (KLa) for all three compounds at all experimental points.

This thesis is the summation of three separate erosion studies that were conducted in the Sycamore Creek watershed. The first, or initial, study is an application of the Musgrave erosion equation to the Sycamore Creek watershed. While the equation predicts erosion with a degree of reliability in the areas for which it was developed, it grossly over-predicts erosion when extrapolated to the semi—arid Southwest. This over- prediction is at least an order of magnitude too high. The second, or channel, study is an application of the Laursen equation to the ephemeral stream that transports the erosion material from the watershed. This study indicates that the Sycamore Creek channel can not transport the erosion material supposedly supplied to it in the initial study. The third, or rainfall simulator, study establishes that the erosion material that could possibly be supplied to the Sycamore Creek channel is at least an order of magnitude less than that predicted by the initial study. Thus it is concluded that an analysis of an ephemeral channel's sediment- carrying capacity, along with an analysis of erosion potential, as derived from a rainfall simulator study, will provide a realistic estimate of yearly erosion from a semi-arid watershed.

Structural health monitoring (SHM) is an emerging field in civil engineering in recent years. The main objectives of the SHM are to identify structural integrity issues at early stage and improve the structural safety through measuring and analyzing structural behaviors. Sensing systems for SHM can be used to identify applied vehicle loads for bridge structures. Bridge weigh-in-motion (BWIM) is one type of such vehicle load identification. As a tool to monitor the vehicle weight moving on the bridges, BWIM uses the structural responses induced by moving vehicle on the bridge to back-calculate vehicle information. In this thesis, optimized BWIM systems using multimetric measurements will be investigated. In Chapter 1, the concept and background of BWIM systems will be introduced. The objective of this research will be also demonstrated in this chapter. Chapter 2 is the literature review section. In Chapter 3, the finite element bridge model adopted for this study will be described. In this section, the moving-load time history analysis, sectional properties for bridge members, and other structural parameters of bridge model will be introduced. The methodology of BWIM systems used in this study will be demonstrated in Chapter 4. In Chapter 5, optimized sensor locations for BWIM using normal and shear strain measurements and acceleration measurement will be discussed for the case without measurement noise. In Chapter 6, sensor location optimization for the case considering measurement noises will be investigated. A new acceleration-based BWIM method is proposed in this section. Non-drift displacement reconstruction technique using acceleration measurement and FIR filtering is applied for BWIM. Finally, Chapter 7 is the conclusion part of this thesis.