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.

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.

No description available.

No description available.

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references.

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1968. / Includes bibliographical references. Includes bibliographical references (leaves 78-80).

Thesis (Ph. D. - Economics)--University of Arizona, 1968. / Includes bibliographical references (leaves 113-115).

Thesis (Ph.D.)--University of Arizona, 2006 / Includes bibliographical references (p. 246-257). Also available via the Internet.

The recreational use of the Colorado River within the Grand Canyon National Park and National Monument increased on the order of 60 to 70 per cent during each year of the interval 1967 to 1970. Consequently, the U. S. National Park Service instituted user limits to protect and preserve the area commencing with the 1971 season. This limit was established with limited data on the users of the river or about their perceptions of the trip experience. A need existed to collect and analyze this type of data, and to suggest possible management alternatives. This study used a mailed questionnaire to a random sample of past participants in order to collect basic socio-economic data. The analysis was based on a 65% response rate, and consisted of individual question tabulation and multivariate data -cluster analysis. The data show background characteristics of the participants, reasons for taking the trip, reactions to the experience, perceptions of problems associated with the trips, reactions to crowded conditions, and needs for regulatory policy concerning user intensities.

From Imperial Dam downstream, in addition to Mexico, the Colorado River supplies water to Arizona and California for predominantly agricultural use. In Arizona, the Colorado River is the major source of water supply to the various irrigation districts in the Yuma area. Due to legal constraints, the amount of Colorado River water available to the State of Arizona is limited. On the other hand, it was discovered that the amount of water applied to the soil in irrigation exceeds that amount needed for crop-growing. Two areas where the amount of water considerably exceeds the requirements, the mesa section of the Wellton-Mohawk Irrigation and Drainage District and the Yuma Mesa Irrigation and Drainage District, were studied in detail. The excess water applied on the mesa of the Wellton-Mohawk Irrigation and Drainage District flows into the Wellton-Mohawk Valley whence it is pumped into a conveyance channel and then discharged into the main channel of the Colorado River. This drain water has a very high salt content and therefore it adversely affects the quality of the river water. Since the drain water is discharged into the Colorado River above the point of diversion to Mexico and it is considered to be part of the Mexican water allotment, the quality of the Colorado River water has become a source of friction between the United States and the Republic of Mexico. The excess irrigation water from the Yuma Mesa Irrigation and Drainage District flows into the adjacent valleys as well as into uncultivated areas. In the adjacent valleys it is raising the water table and thus causing drainage problems. When it flows underground into the uncultivated lands, in large measure it constitutes a loss of water that otherwise could be put to beneficial use by Arizona. It is known that flood irrigation is not conducive to efficient application of water in the sandy soils that are predominant in these areas, and that the effects of this application of excess water are diverse and far-reaching. The change to sprinkler irrigation would be advantageous in many ways and beneficial to all concerned. The change to sprinkler irrigation on the mesa of the Wellton-Mohawk Irrigation and Drainage District would benefit both the farmers and the district financially. At the same time, it would decrease the salinity of the Colorado River water, thereby improving the quality of the water that Mexico receives and, consequently, the relations between the United States and the Republic of Mexico. In the Yuma Mesa Irrigation and Drainage District, the change in the method of irrigation would increase the amount of water available for use by the State of Arizona. Furthermore, it would alleviate the drainage problem of the adjacent valleys and would thereby decrease the amount of drain water flowing back into the channel of the Colorado River. In this district, such a change may entail a small added cost to the farmer. Alternatives for augmenting the flow of the Colorado River, such as importation of water from other basins, desalting sea water, phreatophyte eradication, and evaporation suppression, were found to be economically unfeasible at present or still in the experimental stages.