• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 993
  • 331
  • 35
  • 11
  • 6
  • 6
  • 6
  • 6
  • 6
  • 5
  • 4
  • 4
  • 3
  • 3
  • 3
  • Tagged with
  • 1437
  • 1437
  • 1437
  • 981
  • 802
  • 755
  • 749
  • 384
  • 238
  • 211
  • 198
  • 196
  • 108
  • 77
  • 76
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
571

Land Use Planning for the San Tiburcio Watershed

Armijo, Roberto, Bulfin, Robert 13 April 1979 (has links)
From the Proceedings of the 1979 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 13,1979, Tempe, Arizona / Land use planning, within the context of socio-economic development, is characterized by many conflicting objectives. This paper defines ojectives for the San Tiburcio watershed in northern Mexico. A mixed multiobjective programming model is developed. The model serves as an aid to a group of decision makers in choosing a "satisficing" feasible set of non-mutually exclusive land use alternatives. The paper concludes with a discussion of possible solution techniques.
572

The Impact of Socioeconomic Status on Residential Water Use: A Cross-Section Time-Series Analysis of Tucson, Arizona

Billings, R. Bruce, Acthe, Donald E. 13 April 1979 (has links)
From the Proceedings of the 1979 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 13,1979, Tempe, Arizona / The impact of a selected set of socioeconomic variables on residential water consumption per household is examined using a combined cross-section time-series analysis by census tract for Tucson, Arizona for 1974, 1975, 1976 and 1977. The estimated income elasticity of demand for water is .23, which means that a 10-percent increase in income produces a 2.3 percent increase in water use. Additionally, the number of persons per household and the percent of households with head age 65 or more also are shown to have a strong positive relationship to water use. New residential units are shown to have a strong tendency to utilize less water than older units, presumable because of a shift away from water using yards. Both Black and Spanish-surnamed dominated areas tend to consume a lower than expected amount of water for their income and family size characteristics, but the coefficients on these variables are not sufficiently strong to accept this relationship.
573

A Multi-Objective Approach to River Basin Planning

Gershon, Mark, McAniff, Richard, Duckstein, Lucien 12 April 1980 (has links)
From the Proceedings of the 1980 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 11-12, 1980, Las Vegas, Nevada
574

Evaluation of Water Management Systems for the Sonoita Creek Watershed

Robotham, Hugh B. 13 April 1979 (has links)
From the Proceedings of the 1979 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 13,1979, Tempe, Arizona
575

Irrigation Management and Water Policy: Opportunities to Conserve Water in Arizona

Ayer, Harry W., Hoyt, Paul G. 12 April 1980 (has links)
From the Proceedings of the 1980 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 11-12, 1980, Las Vegas, Nevada
576

Prediction of the Chemical Quality of Streamflow by an Interactive Computer Model

Rasmussen, William O., Ffolliott, Peter F. 12 April 1980 (has links)
From the Proceedings of the 1980 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 11-12, 1980, Las Vegas, Nevada
577

Origin, Development, and Chemical Character of a Perched Water Zone, Harquahala Valley, Arizona

Graf, Charles G. 12 April 1980 (has links)
From the Proceedings of the 1980 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 11-12, 1980, Las Vegas, Nevada
578

Sediment Production from a Chaparral Watershed in Central Arizona

Hook, Thomas E., Hibbert, Alden R. 13 April 1979 (has links)
From the Proceedings of the 1979 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 13,1979, Tempe, Arizona / Sediment production from two chaparral watersheds in central Arizona during a period of heavy winter rainfall in 1978 was compared with sediment production over a 14-year period (1964-78). Results indicate sediment production from chaparral is primarily the result of seasonal periods of heavy precipitation and runoff and not from ephemeral summer rainstorms. Sediments from 300 acres (122 ha) above a newly constructed stock watering tank were produced within a few days time in the late winter of 1978 at an accelerated annual rate of 41.1 ft /acre (2.9 m /ha). The sediments came mostly from cutting in channel alluvium in upstream tributaries where the sediments are presumed to have accumulated from downslope creep, dry ravel, and overland flow produced by ephemeral, convective rainstorms. The accelerated rate of sediment production was more than 4 times the average annual rate of 9.8 ft /acre (0.7 m /ha) determined from 14 years of cumulative sediment deposits in a stock tank constructed in 1964.
579

An Exchange System for Precise Measurements of Temperature and Humidity Gradients in the Air Near the Ground

Gay, L. W., Fritschen, L. J. 13 April 1979 (has links)
From the Proceedings of the 1979 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 13,1979, Tempe, Arizona / Small differences can be very accurately measured with two sensors if precautions are taken to periodically interchange the sensors between observations. The Bowen ratio model of evapotranspiration requires measurements of air temperature and humidity gradients near the evaporating surface. The gradients are in the order of only 0.1 °C/m or 10 Pa/m. Precision in excess of 0.01 °C/m or 1 Pa/m can be obtained only through laborious calibration and replication of instruments, or through periodic interchange. The design of a simple system for interchanging psychrometers is described. The system will exchange sensors between two levels one meter apart at selected time intervals. The vertical exchange path of this design maintains a constant orientation of the sensors and has important advantages over rotating systems used elsewhere. The principles apply to a variety of measurement problems.
580

A Multiattribute Approach to the Reclamation of Stripmined Lands

Brinck, Fritz H., Duckstein, Lucien, Thames, John L. 13 April 1979 (has links)
From the Proceedings of the 1979 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 13,1979, Tempe, Arizona / A multiattribute utility function is used to model preferences on outcomes of alternative reclamation schemes for stripmined lands, using Arizona and Wyoming examples. Each scheme should at least help restore land to its premining value, and is composed of three sets of actions: mining operations, preparations for postmining land use, and mitigating actions. Grazing and runoff augmentation are examples of postmining land use goals, and mitigating actions may be measures to protect the environment like pollution control in runoff or infiltration. Conflicting objectives are involved, including the maintenance of sufficient coal production, the alleviation of detrimental environmental effects, and the minimization of loss. Since the environmental effects are fraught with uncertainty, a multiobjective decision-making scheme under uncertainty is set up to analyze the problem. The decision model ranks alternative reclamation schemes on the basis of the preference function of a group decision maker, each member of which assessing a separate subset of single attribute utility functions.

Page generated in 0.075 seconds