Browsing by Author "Longenbaugh, R. A. (Robert A.), author"

Now showing 1 - 9 of 9

Open Access
A data manager looks at the development of the Colorado Water Data Bank
(Colorado State University. Libraries, 1973-06) Longenbaugh, R. A. (Robert A.), author; McMillin, Norval E., author; Colorado State University, publisher
Open Access
Artificial aquifer recharge in the Colorado portion of the Ogallala Aquifer
(Colorado State University. Libraries, 1984-11) Longenbaugh, R. A. (Robert A.), author; Miles, Donald, author; Hess, Earl, author; Rubingh, James, author; Colorado Water Resources Research Institute, Colorado State University, publisher
Open Access
Computer estimates of natural recharge from soil moisture data, High Plains of Colorado
(Colorado State University. Libraries, 1975) Longenbaugh, R. A. (Robert A.), author; Krishnamurthi, Narayanaswamy, author; Environmental Resources Center, Colorado State University, publisher
The research described briefly in this completion report has shown that transient soil moisture data observed at vertical positions at one station can be used as descriptors of natural groundwater recharge to evaluate its time distribution at that station. Hydraulic properties of the soil and initial and boundary conditions must be known before applying the mathematical model developed in this study to other locations. The model developed in this study assumed that the moisture content of unsaturated soil below the zone of influence of evapotranspiration varies in the linear range of the soil water characteristic curve. The parameters of the model characterize the hydraulic properties of the soil and their spatial variability. They were estimated by a linear statistical model. The mathematical model was solved by a Finite-Difference technique adopting the Crank-Nicholson scheme. The model was verified with an analytical solution and the agreement for the case of homogeneous soil was very good. Field data collected during a drainage cycle were used to verify the model for non-homogeneous soil. The verification was also found to be satisfactory in the latter case. The model was then applied to estimate recharge rates from data collected by the USGS and ARS at the Great Plains Field Experiment Station near Akron, Colorado. Estimated monthly recharge rates varied from a low of 0.02 inches to a high of 1.42 inches. Comparison of the Akron recharge estimates with other data indicates the values were acceptable. An average annual recharge of 4 inches was computed for the Akron site. This result was compatible with the observed rise in the local water table of 3 feet during the same time period.
Open Access
Evaluation of hydrologic and geologic parameters for consideration of designated ground water basins water
(Colorado State University. Libraries, 1966) Duke, Harold R. (Harold Ray), 1940-, author; Longenbaugh, R. A. (Robert A.), author; Colorado State University, publisher
Open Access
Evaluation of irrigation pumping plant efficiencies and costs in the high plains of eastern Colorado
(Colorado State University. Libraries, 1968-12) Miles, Donald L., author; Longenbaugh, R. A. (Robert A.), author; Colorado State University Experiment Station, publisher
Open Access
Evaluation of the method to compute volumes of water pumped from power records
(Colorado State University. Libraries, 1970-04) Longenbaugh, R. A. (Robert A.), author; Colorado State University, Civil Engineering Department, publisher
Open Access
Evaluation of water resources in Kiowa and Bijou Creek basins, Colorado
(Colorado State University. Libraries, 1966-05) Duke, Harold R. (Harold Ray), 1940-, author; Longenbaugh, R. A. (Robert A.), author; Civil Engineering Department, Colorado State University, publisher
This report describes the water resources of the Kiowa and Bijou Creek drainages in northeastern Colorado. These intermittent tributaries to the South Platte River drain some 2130 square miles lying within six counties. The area has a semi-arid climate with an average annual precipitation slightly over 15 inches, most of which falls during the summer months. Since the streams within the study area flow only during storm periods and since there is no water imported into the area, the principle source of water for irrigation is from ground water. It was estimated that the alluvial aquifer contained 2,373,000 acre-feet of water in 1965, and that it receives 55,800 acre-feet of water annually through natural recharge of precipitation. The Fox Hills sandstone formation was considered to be the only bedrock aquifer capable of supplying moderate quantities of water to wells within the study area. This formation contains an estimated 2,000,000 acre-feet of recoverable water within the area, and could be an important future water source. The first significant pumping in the area began in the 1930's, and the annual withdrawal has increased to a maximum of 130,000 acre-feet from about 700 wells for the year 1964. This development has caused ground water level declines as great as 45 feet in some areas. Based upon present management practices, it is anticipated that water levels will continue to decline in the study area, with resultant decreases in the amount of water pumped. Within fifty years, it is expected that the aquifer will be depleted to the point that only recharge water is available for pumping. By this time, however, technology will likely develop such methods as artificial recharge and weather modification to feasibly increase the useable water resources of the area.
Open Access
Ground-water resources in northeastern Colorado
(Colorado State University. Libraries, 1963) Longenbaugh, R. A. (Robert A.), author; Rocky Mountain Association of Geologists, publisher
Open Access
Mathematical simulations for better aquifer management
(Colorado State University. Libraries, 1967) Bittinger, Morton W., author; Longenbaugh, R. A. (Robert A.), author; Duke, Harold R. (Harold Ray), 1940-, author; International Association of Hydrological Sciences, publisher
Manipulation of groundwater storage in conjunction with surface water supplies often requires simultaneous consideration of varied aquifer hydraulic and geometric characteristics, highly variable pumping patterns in time and space, imperfectly connected bodies of surface water and non-deterministic natural recharge. In addition, legal, economic and social conditions impose constraints which must be considered in aquifer operation and management. This paper describes mathematical modeling and computer analysis techniques that allow consideration of the many varied and changing factors mentioned above. Application is made to specific aquifer management problems.