Water management models have evolved through three basic stages. The earliest models dealt with the problem of getting water to where it was needed. Adequate supplies of sufficiently high cudlity were assumed to exist, and thus these models attempted to determine optimal distribution networks. In 1966 J.A. Dracup developed a model of this form to explore alternate sources of supply to meet industrial and municipal demands, agricultural demand, and demand for water to provide artificial recharge of groundwater aquifers. The next developments in water management were due to the emerging awareness of the environmental impacts of water use. These models were primarily concerned with maintaining certain quality levels within the natural water system (rivers, streams, estuaries). They tended to ignore the quantity of water within the system, being concerned with optimizing over the distribution system and quality control through the use of by-pass piping, on-site and regionalized treatment plants. The final category of models is one in which both quality and quantity considerations are allowed to enter as decision variables. The most general model of this type was developed by D.E. Pingry and T.L. Shaftel in 1979. This model allows for any configuration of sources, users, piping, disposal areas, and treatment plants. Thus the problem of distribution and quality control are both handled. This model also employs realistic nonlinear cost functions through economies of scale in treatment, and diseconomies of scale in treatment efficiency. The major limitation of their model, and others of the same type, is that they have been applied only to closed water systems which do not include rivers, streams, etc., and therefore ignore the environmental impacts of the water development on the complete natural water systems (e.g., a river basin). The Pingry-Shaftel model has been expanded to allow for the integration of a river system into an optimization model where the distribution system, quality control, source development, recycling of wastewater, and other management strategy alternatives are all allowed to enter as decision variables. At the same time the quantity requirements and quality standards are being monitored in order to analyze their impacts on cost. Decomposing the problem and making use of a large-scale transportation algorithm permit a solution to be obtained in an efficient manner. The model has sufficient flexibility to permit the comparison of impacts of various natural, technological, economic, and legal constraints. The model has been applied to the Colorado River Basin under varying assumptions in order to determine the economic and environmental implications of various water supply allocations and salinity treatment strategies.

Water quality analyses in Grand Canyon examined Colorado River and tributary baseline water quality status in relation to recreational float trip use of the river corridor. Float trip use of Grand Canyon has increased over recent years (since 1966) to levels which have caused concern for water quality-river running associations. River runners have traditionally used the Colorado River and tributaries as sources of drinking and cooking water, for swimming and bathing, and, at times, as a disposal for some refuse, e.g., dishwater and leftover food. Associated with float trip use of the river corridor water resources has been potential water quality hazards. During the 1972 and 1979 float trip seasons (May through September) outbreaks of gastroenteritis occurred among river runners in Grand Canyon, prompting investigation by the Center for Disease Control, Atlanta, Georgia; an enteric pathogen Shigella sonnei was isolated from some river-trip participants. Potentially, the Colorado River or a tributary served as a source or carrier of the pathogen, though this has not been confirmed. Enteric disease organisms excreted in feces by humans, wildlife or domestic animals can become potential sources of infection; water contaminated with fecal organisms can distribute diseases. Water quality analyses of the Colorado River corridor occurred during the 1978 and 1979 river running seasons. Examination of the extensive river corridor necessitated analyses in the field. Travel through the Grand Canyon was via research rafts in a series of six float trips, April through September, in 1978, and two float trips, July and August, in 1979; 82 field days in 1978 and 22 field days in 1979. A total of 497 water quality samples were collected over two seasons from the Colorado River along the 225-mile stretch from Lees Ferry to Diamond Creek, the launch and take-out points of the research trips. The confluent reaches (within approximately 200 yards of the Colorado River) of 26 side creeks in the river corridor were also sampled in 1978; nine tributaries were sampled in 1979. Additional samples collected from upstream locations on some side creeks increased the tributary sample site total to 33 in 1978 and to 13 in 1979 for a two season total of 165 individual tributary samples. Selected microbial, physical, and chemical parameters were measured to determine baseline water quality status in the Colorado River corridor of Grand Canyon. Research emphasis was on microbial water quality; physical and chemical parameters were measured to facilitate evaluation of the microbial profiles. Microbial parameters included fecal coliform bacteria and fecal streptococcus bacteria densities; physical parameters included turbidity and water and air temperature; chemical determinations included alkalinity, hardness, phosphate, nitrate, chloride, total dissolved solids, and pH. Data from 1978 and 1979 show that the Colorado River and tributaries have similar bacterial water quality profiles. Surface waters show predominantly low FC densities, indicating high quality waters for recreational activities, based on established federal and state water quality standards. Treatment of river and tributary surface water is necessary to assure drinking water quality standards. Bottom sediment analyses modify considerably the water quality status represented by surface water analyses alone. Significant densities of enteric organisms are present in the river and tributary environments, representing an important water quality hazard. Associated with resuspension of bottom sediments is the probability of surface water contamination by enteric organisms. Recreational activities, particularly water play in confined tributary pools, can bring river runners in direct contact with concentrated sediment suspension in surface waters.

Natural resource data are typically non-linear and complex, yet modeling methods often utilize statistical analysis techniques, such as regression, that are insufficient for use on such data. This research proposes an innovative modeling method based on pattern recognition techniques borrowed from the field of machine learning. These techniques make no data distribution assumptions, can fit non-linear data, can be effective on a small data set, and can be weighted to include relative costs of different predictive errors. Rapid Assessment Protocols (RAPs) are commonly used to collect, analyze, and interpret stream data to assist diverse management decisions. A modeling method was developed to predict the outcome of a RAP in an effort to improve accurate prediction, weighted for cost-effectiveness and safety, while prioritizing investigations and improving monitoring. This method was developed using channel stability data collected from 58 high-elevation streams in the Upper Colorado River Basin. The purpose of the research was to understand the relationships of channel stability to several hydrobiogeomorphic features, easily derived from paper or electronic maps, in an effort to predict channel stability. Given that the RAP used was developed to evaluate channel stability, the research determined: 1) relationships between channel stability and major land-use and hydrobiogeomorphic features, and 2) if a predictive model could be developed to aid in identifying unstable channel reaches while minimizing costs, for the purpose of land management. This research used Pearson's and chi-squared correlations to determine associative relationships between channel stability and major land-use and hydrobiogeomorphic features. The results of the Pearson's correlations were used to build and test classification models using randomly selected training and test sets. The modeling techniques assessed were regression, single decision trees, and bagged (bootstrap aggregated) decision trees. A cost analysis / prediction (CAP) model was developed to incorporate cost-effectiveness and safety into the models. The models were compared based on their 1) performance and 2) operational advantages and disadvantages. A reliable predictive model was developed by integrating a CAP model, receiving operator characteristic curves, and bagged decision trees. This system can be used in conjunction with a GIS to produce maps to guide field investigations. / Graduation date: 2001

Prepared for the Bureau of Reclamation and the Office of Water Research and Technology, U.S. Department of the Interior, By the University of Arizona, University of California, Los Angeles and the University of Nevada, August 1976. / Current and recent research (1972 -1976) concerning water resources in the Lower Colorado River Basin is abstracted and compiled into a bibliography. Data were gathered by contacting research personnel and requesting information via questionnaire. The report is indexed by principal investigator, keyword and funding source. In addition, the project descriptions are contained in a computerized data file and easily accessed by contacting the Office of Arid Lands Studies, University of Arizona, Tucson, AZ. The information can be retrieved by keyword, principal investigator, state, funding source and geographic location.

Dissertation (PhD)--University of Arizona, Tucson, Arizona, 2005. / Includes bibliographical references.

This research presents the Colorado River basin as a social-ecological system. Utilizing event data on cooperative and conflictive interactions over fresh water, the system is decomposed to look for evidence of outcomes of resilience enhancement. The Animas-La Plata Project in the upper San Juan basin is presented as a case study, and qualitative methods are used to analyze interactions that led to its construction in order to assess social-ecological outcomes. In the upper San Juan basin, cooperative interactions over fresh water outnumbered conflictive ones. Interactions over water rights and infrastructure were most common, and the most cooperative interactions focused on these issue types. Many of these interactions focused on the Animas-La Plata Project compromise, which ultimately enhances social-ecological resilience in the Colorado River basin. / Graduation date: 2012

A dramatic increase in the number of individuals taking float trips on the Colorado River through Grand Canyon National Park has occurred over the last decade. The National Park Service has attempted to protect the fragile river corridor from "overuse" through implementation of the 1979 River Management Plan. A survey of users taking float trips through Marble and Grand Canyons has been conducted to measure attitudes about National Park Service management policies of the river trips. The study has been designed to categorize users along a wildernist scale and determine whether a difference in attitude concerning river management policy existed between more wilderness oriented participants and less wilderness oriented participants. Users have been categorized into three wildernist categories: Neutralists, Slight Wildernists, and Moderate Wildernists. Attitudes regarding river and canyon management policy were significantly different between wilderness categories in ten of sixteen policy questions. Also, a significant difference existed in attitudes when comparing pre- and post-trip responses. Mode of travel was associated with mean wilderness scores. Two survey instruments have been used in the study: a self-administered questionnaire and a paired-picture comparison interview. Description of the two instruments used as well as a discussion of the major findings are presented.

Forecasts of hydrological information are vital for many of society's functions. Availability of water is a requirement for any civilization, and this necessitates quantitative estimates of water for effective resource management. The research in this dissertation will focus on the forecasting of hydrological quantities, with emphasis on times of anomalously low water availability, commonly referred to as droughts. Of particular focus is the quantification of uncertainty in hydrological forecasts, and the factors that affect that uncertainty. With this focus, Bayesian methods, including ensemble data assimilation and multi-model combinations, are utilized to develop a probabilistic forecasting system. This system is applied to the upper Colorado River Basin for water supply and drought forecast analysis. This dissertation examines further advancements related to the identification of drought intensity. Due to the reliance of drought forecasting on measures of the magnitude of a drought event, it is imperative that these measures be highly accurate. In order to quantify drought intensity, hydrologists typically use statistical indices, which place observed hydrological deficiencies within the context of historical climate. Although such indices are a convenient framework for understanding the intensity of a drought event, they have obstacles related to non-stationary climate, and non-uniformly distributed input variables. This dissertation discusses these shortcomings, demonstrates some errors that conventional indices may lead to, and then proposes a movement towards physically-based indices to overcome these issues. A final advancement in this dissertation is an examination of the sensitivity of hydrological forecasts to initial conditions. Although this has been performed in many recent studies, the experiment here takes a more detailed approach. Rather than determining the lead time at which meteorological forcing becomes dominant with respect to initial conditions, this study quantifies the lead time at which the forecast becomes entirely insensitive to initial conditions, and estimating the rate at which the forecast loses sensitivity to initial conditions. A primary goal with this study is to examine the recovery of drought, which is related to the loss of sensitivity to below average initial moisture conditions over time. Through this analysis, it is found that forecasts are sensitive to initial conditions at greater lead times than previously thought, which has repercussions for development of forecast systems.

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