This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1983. / Includes bibliographical references (leaves 204-207).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1981. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 91-95).

Thesis (D.Sc.)--Stellenbosch University, 1953. / ENGLISH ABSTRACT: no abstract available / AFRIKAANSE OPSOMMING: geen opsomming

The increase in irrigated agriculture in Saudi Arabia is having a large impact on its limited groundwater resources. While large-scale water storage changes can be estimated using satellite data, monitoring groundwater abstraction rates is largely non-existent at either farm or regional level, so water management decisions remain ill-informed. Although determining water use from space at high spatiotemporal resolutions remains challenging, a number of approaches have shown promise, particularly in the retrieval of crop water use via evaporation. Apart from satellite-based estimates, land surface models offer a continuous spatial-temporal evolution of full land-atmosphere water and energy exchanges. In this study, we first examine recent trends in terrestrial water storage depletion within the Arabian Peninsula and explore its relation to increased agricultural activity in the region using satellite data. Next, we evaluate a number of large-scale remote sensing-based evaporation models, giving insight into the challenges of evaporation retrieval in arid environments. Finally, we present a novel method aimed to retrieve groundwater abstraction rates used in irrigated fields by constraining a land surface model with remote sensing-based evaporation observations. The approach is used to reproduce reported irrigation rates over 41 center-pivot irrigation fields presenting a range of crop dynamics over the course of one year. The results of this application are promising, with mean absolute errors below 3 mm:day-1, bias of -1.6 mm:day-1, and a first rough estimate of total annual abstractions of 65.8 Mm3 (close to the estimated value using reported farm data, 69.42 Mm3). However, further efforts to address the overestimation of bare soil evaporation in the model are required. The uneven coverage of satellite data within the study site allowed us to evaluate its impact on the optimization, with a better match between observed and obtained irrigation rates on fields with higher frequency of available data. The inclusion of novel remote sensing sources (e.g. CubeSats) that offer higher frequencies and higher resolution can also be explored to improve the methodology, although further validation of these systems is needed. The developed framework has the potential to be used as a water management tool to monitor groundwater losses over large remote regions.

Rainwater harvesting (RWH) is a method of capturing rainfall from a catchment surface and storing it for later use. Though it has been around for thousands of years, its popularity and use has been increasing in recent years and water quality within RWH systems has become a concern. Water temperature is a parameter of water quality and storage container color and shading affect this temperature. Four different colors and three different shadings were applied to twelve rainwater storage barrels. Water temperature of these barrels was measured over twenty weeks during a Texas summer. During the initial ANOVA model, it was determined that the color and shade variables had an interaction and thus both together had an effect on the water temperature. Though the individual treatment variables could not be analyzed and compared statistically, the trends showed that light colors and higher shading caused lower water temperatures in the storage containers. Also, the color had more pronounced effect than shading on water temperature inside the barrels.

Project Completion Report, OWRT Project No. A-091-ARIZ / Agreement No. 14-34-0001-8003 / Project Dates: October 1978 - September 1979 / Acknowledgement: The work upon which this report is based was supported by funds provided by the United States Department of the Interior, Office of Water Research and Technology, as authorized under the Water Resources Research Act of 1978. / This report contains the results of a one year study to develop improved methods of evaporation control using wax impregnated foam. The foam used was expanded polystyrene and the wax used was paraffin with a 140° F melting point. The report tells of a pressure chamber that was used to wax impregnate sheets of expanded polystyrene. Based on tests made in the laboratory the pressure chamber was modified into a vacuum chamber. Problems were encountered getting the interior of the sheets impregnated using a vacuum. There was no way this problem could have been predicted based on the smaller laboratory models. The pressure method, however, was successfully used to impregnate up to 3 -inch thick sheets of expanded polystyrene. During the project it was found that the paraffin impregnated rafts worked very well until high temperatures, 100° F plus, are encountered Under dusty conditions. The heat causes the surface of the wax to get tacky, the dust darkens the otherwise white surface, which in turn captures more heat, and then more dust, etc. The high surface temperature caused an accelerated weathering of the material. Because of this, waxes with higher melting points were tried. Additional work is needed in this area as no satisfactory combinations were found. Two polyethylene copolymers with a melting point close to the 190° F destruction point of the expanded polystyrene were tested. This wax was too viscous for impregnation but provided a hard surface coating when the previously wax impregnated expanded polystyrene is dipped into the molten polyethylene wax. This dipping might be the best method for surface protection at low cost but additional testing is needed before trying the material out on a large scale. Progress was made in the development of wax impregnated lightweight concrete rafts. The wax impregnation of the lightweight raft solves the vapor penetration problem. This type of raft was found to resist removal by wind and weathered very well in the one year of testing. Connecting rafts with strips of sheet metal bonded to the expanded polystyrene was done on a small scale, and needs to be field tested. The PVC pipe C clamps work well on partially submerged rafts but need to be lengthened to interconnect wax impregnated rafts. Square wax impregnated rafts lx1 ft in size did not stay on a small test pond in high wind. Circles are presently being tried but additional testing is needed in this area before their reliability is known.

No description available.

Water management is a critical issue around the world. In South Australia, and throughout Australia, demand for water has increased beyond the capacity of existing water supply systems. For this reason there is great interest in optimal management of water resources at both a national and local level. / In this thesis I discuss the capture and treatment of urban stormwater and suggest practical strategies for water storage in a sequence of dams. My primary motivation was a proposal for the capture, treatment and storage of all stormwater and wastewater on a new suburban housing estate at Mawson Lakes in South Australia, while minimising overflow. / A discrete state mathematical model for the management of water in a system of two connected dams is described in detail, through the use of stochastic matrices. I assume random inputs and regular demand. The system is controlled by pumping water from the first to the second dam. Only practical policies are considered. My initial analysis was restricted to a class of policies that depends only on the content of the first dam. The steady state of the system can be determined for each particular control policy. To determine the steady state I have used Gaussian elimination to reduce the problem of solving a large set of linear equations to a much smaller set. The steady state is an invariant measure that determines the long-term expected overflow. The systematic state reduction procedure subsequently allowed me to consider more complex policies that depend on the content of both dams. One such policy that I analyse in detail is to pump to fill the second dam. Though it is not yet proven this policy is possibly the optimal policy from among the classes considered. I also extend the discrete state model to a system of two connected dams with continuous input into the first dam. The stochastic matrices are replaced by integral operators on a space of bounded probability measures. / An alternative general analysis is described for the policy of pumping to fill the second dam. By using the characteristic pattern of the steady state equations I can define new variables and equations to reduce the problem to a much smaller system of equations. This method was also applied to policies in which I overfill or underfill the second dam. All three solutions are closely related. Yet another method uses a set of superstates. Each superstate is a set of states for which the particular control policy defines a common outcome. Once again the invariant measure is found by solving a reduced order matrix equation. I have also illustrated this method in a particular example. It is entirely possible that my various solution methodologies can be directly related. Although no analysis has yet been done further research into general reduction procedures would be certainly worthwhile. / For each class of controls a computer simulation was used to confirm the theoretical results. The simulation of the two dam system was extended to a system with many dams that is similar to the one proposed at Mawson Lakes. Future investigations include the development of mathematical models and theoretical solutions for the recently revised stormwater storage system at Mawson Lakes. / Thesis (PhDMathematics)--University of South Australia, 2004.