Equus Beds Research Articles

Development of a Model for Simulation of Solute Transport in a Stream–Aquifer System

A model for simulation of solute transport in a dynamic stream–aquifer system is developed by integrating four existing sub-models. Interface packages are created to link the sub-models. The developed model is successfully used to simulate chloride transport in the stream–aquifer system of the Arkansas River and the Equus Beds Aquifer in Kansas and demonstrates that chloride concentration in the aquifer decreases in the vicinity of the simulated channel over time.

Modern geostatistics: computational BME analysis in the light of uncertain physical knowledge - the Equus Beds study

This paper is concerned with a computational formulation of the Bayesian maximum entropy (BME) mapping method, which can handle rigorously and efficiently spatiotemporal applications of considerable practical importance. BME is a method of modern geostatistics that can integrate and process physical knowledge that belongs to two major bases: general knowledge (i.e., obtained from general principles and laws, summary statistics and background information), and specificatory knowledge (i.e., obtained through experience with the specific situation). BME allows considerable flexibility regarding the choice of an appropriate spatiotemporal map, offers a complete assessment of the mapping uncertainty and contributes to the scientific understanding of the underlying natural phenomenon. Valuable insight is gained by studying a spatiotemporal data set representing water-level elevations at the Equus Beds aquifer (Kansas). Numerical results show that, as was expected in theory, classical geostatistics analysis is obtained as a special case of the considerably more general BME approach. Moreover, modern geostatistical analysis in terms of BME offers more accurate and informative results in practice, by incorporating various sources of physical knowledge that cannot be processed by the classical methods.

IRP: a case study from Kansas

Recharging a depleted aquifer is an integral part of the resource plan in Wichita, Kan.Because current supplies will not adequately meet its needs beyond 2010, the city of Wichita, Kan., applied the integrated resource planning (IRP) process to develop a long‐term water resource plan. The plan is environmentally, socially, and economically acceptable to the community and holistically uses the city's local water resources on an “as‐available” basis. Key elements of the plan in addition to water conservation and watershed management are use of trichloroethylene‐remediated and high‐chloride groundwater, above‐base (excess) flow from the Little Arkansas River, expansion of a local wellfield, and recharge of a primary existing water source called the Equus Beds Wellfield. Overpumping by irrigators, industries, and municipalities during the last 40 years caused a drawdown storage volume in the Equus Bed Wellfield, which can hold 100 bil gal of water. Recharging the aquifer replenishes groundwater storage and minimizes flow of chloride‐contaminated water into the wellfield.

VELOCITY CONTROL AS A TOOL FOR OPTIMAL PLUME CONTAINMENT IN THE EQUUS BEDS AQUIFER, KANSAS1

ABSTRACT: A ground‐water‐management model was developed to investigate the best management options for the containment of an oil‐field‐brine plume in the Equus Beds aquifer in south‐central Kansas. The main purpose of the management model was to find the optimal locations and minimum rates of pumpage of a set of plume‐interception wells, to successfully reverse the velocity vectors at observation wells located along the plume front, and also to satisfy freshwater demands from supply wells. The effects of the calculated minimum withdrawals from the interception wells on the migration of contaminants throughout the ground‐water system were evaluated utilizing a solute‐transport model. This latter analysis was carried out to ensure the containment of the plume. Whereas application of the management model to the study area achieves the management objectives, the implementation of the results is believed to be impractical and expensive. This is because a considerable amount of water must be pumped out to reverse the velocity vectors in the vicinity of the plume. In general, the proposed technique of pollutant containment may be effective when applied to aquifers having low hydraulic gradients and/or to aquifers with hazardous plumes whose containment is not subject to economic constraints.

Groundwater-flow parameter estimation and quality modeling of the Equus Beds aquifer in Kansas, U.S.A.

The salinity problems created in the Burrton area as a result of poor oil-field brine disposal practices of the past continue to be a major concern to the area depending on the Equus Beds aquifer for water, including the City of Wichita, Kansas. In this paper, an attempt is made to predict where and how fast the brine plume will move in this area, and what the average chloride concentrations in different parts of the aquifer are. In order to make such predictions, it was necessary to get a calibrated model of the groundwater-flow velocity field. Multiple regression analysis is used for parameter estimation of the steady-state groundwater-flow equation applied in the most critical area of the Equus Beds aquifer. Results of such an analysis produced a correlation coefficient of 0.992 between calculated and observed values of hydraulic head. A chloride transport modeling effort is then carried out despite some serious data deficiencies, the significance of which are evaluated through sensitivity analysis. Thus, starting with the quasi steady-state conditions of the early 1940's, it was possible to match the present chloride distribution satisfactorily. Chloride concentration predictions made for the year 2000 indicate that the quality of the Wichita well-field waters will not generally deteriorate from their present condition by that time.

Sampling design optimization for spatial functions

A new procedure is presented for minimizing the sampling requirements necessary to estimate a mappable spatial function at a specified level of accuracy. The technique is based on universal kriging, an estimation method within the theory of regionalized variables. Neither actual implementation of the sampling nor universal kriging estimations are necessary to make an optimal design. The average standard errorand maximum standard error of estimationover the sampling domain are used as global indices of sampling efficiency. The procedure optimally selects those parameters controlling the magnitude of the indices, including the density and spatial pattern of the sample elements and the number of nearest sample elements used in the estimation. As an illustration, the network of observation wells used to monitor the water table in the Equus Beds of Kansas is analyzed and an improved sampling pattern suggested. This example demonstrates the practical utility of the procedure, which can be applied equally well to other spatial sampling problems, as the procedure is not limited by the nature of the spatial function.

Wichita's Past, Present, and Future Water Supply

This article begins by providing a brief overview of the water supply of Wichita, Kansas, and the development of the Equus Beds water supply. The Cheney Reservoir water supply project is discussed, particularly water management considerations.

Westward Extension of the Kansas "Equus Beds"

A well-developed early Pleistocene terrace which extends along the valley of the Smoky Hill River through Ellis, Russell, and Ellsworth counties, Kansas, is described. An abandoned high-level valley-the Wilson Valley-which carried the drainage of the early Pleistocene upper Saline River, enters the Smoky Hill Valley at the high-terrace level in northwestern Ellsworth County. Several invertebrate faunules and associated vertebrate remains are listed from these Pleistocene deposits. On the basis of physiographic data the terrace deposits and the sediments underlying the floor of Wilson Valley are considered as equivalent, in part, to the McPherson formation (restricted) of the Equus beds area of central Kansas. The described terraces and abandoned valley constitute new data pertaining to the Pleistocene drainage history of central and northern Kansas.

Stratigraphy and Paleontology of a New Middle and Upper Pliocene Formation of South-Central Kansas

The stratigraphy of the Emma Creek formation, a newly differentiated Middle and Upper Pliocene formation of south-central Kansas, is described. The lithology of the formation and its origin, source areas, and physiographic history are discussed. The vertebrate fossils of this formation, the younger McPherson formation (restricted), and the early controversy over the dating of the "McPherson Equus Beds" are discussed.

Geology and ground-water resources of the "Equus beds" area in south central Kansas

This paper summarizes the results of a detailed investigation by the U. S. Geological Survey in cooperation with the Kansas State Geological Survey, Kansas State Board of Health, and the City of Wichita. The geology of the area has been remapped, and several new formations have been established, including the Emma Creek formation of middle and upper Pliocene age, and a thick loess deposit. The hydrologic studies involved extensive test drilling and resulted in the development of a new groundwater supply for the City of Wichita.

Vertebrate Fossils from McPherson Equus Beds

Vertebrate Fossils from McPherson Equus Beds

Vertebrate Fossils from McPherson Equus Beds

This report is supplementary to a report by H. H. Nininger: Pleistocene Fossils from McPherson County, 1921 to 1924, paper 40 of the 1924 meeting at McPherson. Trans. K. A. S. 31:96; and H. J. Harnly, Vertebrate Fossils From McPherson Equus Beds, Trans. K. A. S. 35:209. The fossils here reported were found in the gravel on the Hammann farm, 11/ miles west and 41/2 miles north of Conway, and were presented to the McPherson College Museum by John Akers. The determinations have been made by H. H. Lane. 1. Equus leidge: A. Complete typical tooth. B. Several fragments. 2. Smilodon sp? (Sabre-tooth cat) probably fatalis or nebraskensis. A. A complete cranium. B. Three front teeth from different sand pits. 3. Fragmented tusk of Elephas sp?

A Fossil Tusk Found in the Equus Beds in McPherson County

A Fossil Tusk Found in the Equus Beds in McPherson County

The McPherson Equus Beds

The McPherson Equus Beds

Shufeldt on Fossil Birds from Oregon A Study of the Fossil Avifauna of the Equus Beds of the Oregon Desert R. W. Shufeldt

Shufeldt on Fossil Birds from Oregon A Study of the Fossil Avifauna of the Equus Beds of the Oregon Desert R. W. Shufeldt