Technical and Special Reports
These technical and special reports contain the results of TWRI-funded research.
Recent Submissions
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Adams, J. W.; Jones, L. L.; Beattie, B. R.; Coffman, W. S. (Texas Water Resources Institute, April 1976)[more][less]
URI: http://hdl.handle.net/1969.1/6295 Files in this item: 0
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Lacewell, R. D.; Patton, W. P. (Texas Water Resources Institute, September 1977)[more][less]
Abstract: Agriculture uses large quantities of energy to pump groundwater for irrigation. This means the cost of energy has important implications for the industry in terms of costs and profitability. Increases in the prices of energy sources such as natural gas, electricity, liquid petroleum gas and diesel can cause economic hardship for irrigators, particularly if those increases are unanticipated. The purpose of this paper is to briefly summarize important trends in the current domestic energy situation that could have significant impacts on the future cost and availability of energy, and to show what the implications of those trends are for irrigated agriculture. The primary focus of this study will be on trends in natural gas, since natural gas is the major fuel used for irrigation in the Great Plains states. URI: http://hdl.handle.net/1969.1/6294 Files in this item: 0
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Beattie, B. R.; Foster, H.S. (Texas Water Resources Institute, May 1978)[more][less]
Abstract: This research was undertaken to specify and estimate a model relating household demand for urban water to its principal determinants. Four specific tasks were accomplished: 1. An appropriate economic demand model for urban-residential water supplies was postulated. An improved specification of the rainfall variable was developed to account for turf maintenance demand. The price of water was specified in exponential form making its elasticity price dependent. 2. Parameters of the model were estimated based on pooled data representing a cross-section of U.S. cities. 3. Parameters were estimated for a regionalized version of the model by incorporating sets of dummy variables. Tests for statistical differences among key economic coefficients were made to ascertain regional differences, if any. 4. Parameters were estimated for a model disaggregated by size-of-city categories again by incorporating dummy variable sets. Tests for statistical differences among key economic coefficients were made to ascertain differences among size-of-city categories, if any. The demand models were fitted using 1960 and 1970 data and ordinary least squares regression techniques. Explanatory variables included price, income, precipitation (during the defined growing season) and number of residents per meter in addition to sets of dummy variables on the constant factor and price and income coefficients. The results suggest that size of city is not statistically significant in determining the residential demand for urban water. However, regional differences are significant. For the regional model, price, income, and residents per meter were significant at the 1 percent level for the 1960 data; price and precipitation were significant at the 1 percent level for the 1970 data. R2-values were .74 and .71 for the 1960 and 1970 data, respectively. Income and price elasticities are presented for all regions at the mean price level and for one standard deviation above and below this price level. Mean price level elasticities ranged between -.30 and -.82 and between -.33 and -.67 for the 1960 and 1970 data, respectively, suggesting an inelastic residential water demand at present price levels. The elasticity estimates derived from the regional coefficients of this study compare favorably with those of earlier more micro-level analyses. URI: http://hdl.handle.net/1969.1/6293 Files in this item: 0
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Ruesink, L. E. (Texas Water Resources Institute, May 1977)[more][less]
Abstract: A readership survey conducted in May 1977 found that readers of Texas Water Resources find it useful, attractive and informative. The bulletin is published by the Texas Water Resources Institute to generate public awareness and understanding of water resources issues. The 31 percent response rate from the survey was evidence that the publication is well received. Results indicate that each copy is read by an average of three individuals. Ninety-eight percent of all responses were in favor of the publication. URI: http://hdl.handle.net/1969.1/6292 Files in this item: 0
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Smeins, F. E. (Texas Water Resources Institute, March 1977)[more][less]
Abstract: Water requirements for the United States will triple by the year 2000 (Water Resources Council, 19689. In Texas and many western states about 75% of the total water used is from ground water and this source in many areas is rapidly being depleted. To meet future demands water will have to come from other sources (Runkles, 1972). A possible source is increased water yield from watersheds. The quantity and quality of this surface runoff is influenced by many factors which include precipitation pattern, vegetation-type, soil-type and land use. If surface runoff from watersheds is to be a potential water source, the impact of these factors on water quality and yield must be evaluated. Forests, grasslands and shrublands cover vast watersheds in Texas and North America. Many watershed studies have been conducted in forested regions, but rangeland areas have received only limited attention, particularly in Texas. The significance of these latter types cannot be overlooked since 40% of the land surface in the United States and 60% of Texas support this type of vegetation. The major use of rangeland is domestic livestock and wildlife production. The impact of this use on water yield and nutrient and sediment loss from watersheds requires investigation. The influence of various grazing systems and intensities must be determined in order to coordinate ranching practices with increased high quality runoff. The effect of brush control on runoff yield and quality has not been thoroughly investigated. The purpose of this study was to determine the influence of vegetation characteristics, grazing systems and precipitation on surface runoff from rangeland on the Edwards Plateau region of Texas. Water yield, organic-N, N03-N, NH4-N, N02-N, total and ortho-P, Ca, Mg, K, pH, conductivity, total and calcium hardness, turbidity and suspended sediment load were quantitively evaluated. Field sampling was conducted on small-gauged watersheds on the Texas A&M Agricultural Research Station at Sonora, Texas. These gauged watersheds, which have been established over the past 13 years by the Agricultural Research Service (ARS), represent a variety of grazing systems ranging from continuous heavy grazing with poor vegetation cover to fourpasture and seven-pasture deferred rotation systems with good cover. In addition several different techniques have been used for woody plant control on the watersheds. The Sonora Research Station, with over 25 years of grazing management research, provides a unique area for study of the effects of grazing management and brush control on surface runoff, nutrient load and sediment yield. URI: http://hdl.handle.net/1969.1/6291 Files in this item: 0
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