Engineering Commons^™

Preliminary Evaluation Of The Effects Of A Pumping Well On Existing Surface Water Resources Located In T. 12n, R. 2e, Sec. 23, Cache And Box Elder Counties, Denny J. Johnson, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

This report contains the results of a preliminary study of the impact of pumping a well located in T. 12N, R. 2E, sec. 23, Cache and Box Elder Counties, Utah. A semianalytical capture zone analysis was performed to determine if pumping at the well is likely to reduce flow in Willow Creek or any of three springs in the surrounding area. The well has been used from 1974 to present and is sometimes pumped at 90 gallons per minute (gpm) (verbal communication, Veibell, 1996).

On Hack's Law, Riccardo Rigon, Ignacio Rodriguez-Iturbe, Amos Maritan, Achille Giacometti, David G. Tarboton, Andrea Rinaldo

Civil and Environmental Engineering Faculty Publications

Hack's law is reviewed, emphasizing its implications for the elongation of river basins as well as its connections with their fractal characteristics. The relation between Hack's law and the internal structure of river basins is investigated experimentally through digital elevation models. It is found that Hack's exponent, elongation, and some relevant fractal characters are closely related. The self-affine character of basin boundaries is shown to be connected to the power law decay of the probability of total contributing areas at any link and to Hack's law. An explanation for Hack's law is derived from scaling arguments. From the results we …

Software For Optimizing Groundwater Or Conjunctive Water Management, Richard C. Peralta, Alaa H. Aly

Civil and Environmental Engineering Faculty Publications

US/REMAX is a computer program designed to assist water managers in developing optimal groundwater and/or surface water strategies for a wide range of management problems. It employs response matrix, regression and other methods adapted for nonlinear systems. US/REMAX performs deterministic or reliability-based, single- or multi-objective optimization. Decision variables are ground-water extraction/injection and/or surface water diversion. State variables include water flows, stages and concentrations. Hard coded objective functions and constraints are linear, nonlinear, integer or mixed integer. Special constraints can be added to address unusual situations.

A Spatially-Distributed Hydrologic Model For A Small Arid Mountain Watershed, Thomas H. Jackson, David G. Tarboton, Keith R. Cooley

Civil and Environmental Engineering Faculty Publications

A distributed water balance model was developed as a part of an intensive-field study to simulate the snowmelt-driven hydrologic response of a small mountain watershed using measured values of solar radiation, wind speed, air temperature, relative humidity and precipitation as input.

Snowmelt and evapotranspiration were modeled with point energy balances, written in terms of the snow surface and soil surface temperatures, respectively, corrected for local topographic characteristics and snow drifting. Meltwater was routed to the basin outlet as topography-driven, saturated subsurface flow, with all flow in excess of local transmissivity taken as surface runoff.

The model was calibrated with 1985-6 …

Toward A Balanced Strategy To Address Contaminated Groundwater Plumes At The Massachusetts Military Reservation, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

This document contains the findings and recommendations of the Technical Review and Evaluation Team (TRET) for the plume containment project at the Massachusetts Military Reservation (MMR). The findings and recommendations are in response to the 60 Percent Plume Containment Design, submitted by Operational Technologies (OpTech) in January 1996. In short, the TRET recommends the MMR depart substantially from the strategy of simultaneous, 100 percent containment and treatment that was assigned to OpTech for design in accordance with the Record of Decision (ROD) for Interim Action. This strategy guided the course of the plume containment project over the past two years

Geometric Stiffness Effects On Data Recovery Of An Idealized Mast/Blanket Model, Paul A. Bosela, D. R. Ludwiczak

Civil and Environmental Engineering Faculty Publications

The photovoltaic arrays for the international space station consist of a pre-tensioned blanket of solar collectors and a deployable mast. NASA uses the MSC/NASTRAN finite element program for modeling the dynamic response of the structure due to various loading conditions, such as plume impingement during shuttle docking. This finite element program uses the updated stiffness matrix (elastic plus geometric, or initial stress stiffness matrix) in determining the natural frequencies and mode shapes, as well as the dynamic response, of a pre-loaded structure. However, during the data recovery phase, when the moment and shear at the supports, and internal stresses are …

A Nonparametric Wet/Dry Spell Model For Resampling Daily Precipitation, Upmanu L. Lall, Balaji Rajagopalan, David G. Tarboton

Civil and Environmental Engineering Faculty Publications

A nonparametric wet/dry spell model is developed for resampling daily precipitation at a site. The model considers alternating sequences of wet and dry days in a given season of the year. All marginal, joint, and conditional probability densities of interest (e.g., dry spell length, wet spell length, precipitation amount, and wet spell length given prior to dry spell length) are estimated nonparametrically using at-site data and kernel probability density estimators. Procedures for the disaggregation of wet spell precipitation into daily precipitation and for the generation of synthetic sequences are proffered. An application of the model for generating synthetic precipitation traces …

Effect Of Subsurface Heterogeneity On Free-Product Recovery From Unconfined Aquifers, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

Free-product record system designs for light-hydrocarbon-contaminated sites were investigated to evaluate the effects of subsurface heterogeneity using a vertically integrated three-phase flow model. The input stochastic variable of the areal flow analysis was the log-intrinsic permeability and it was generated using the Turning Band method. The results of a series of hypothetical field-scale simulations showed that subsurface heterogeneity has a substantial effect on free-product recovery predictions. As the heterogeneity increased, the recoverable oil volume decreased and the residual trapped oil volume increased. As the subsurface anisotropy increased, these effects together with free- and total-oil contaminated areas were further enhanced. The …

Optimal Pumping Strategies To Maximize Dissolved Tce Extraction At Mather Afb, California, Richard C. Peralta, Alaa H. Aly

Civil and Environmental Engineering Faculty Publications

USU first estimated the future TCE concentrations that would result if no pumping strategy were implemented (Figure 5, Scenario AO). Then USU used the procedure of Appendix B with the model formulation of Appendix C to compute optimal pumping strategies. In computing optimal strategies USU cycled until an arbitrary three percent contaminant mass convergence criterion was satisfied.

A New Pre-Loaded Membrane Geometric Stiffness Matrix With Full Rigid Body Capabilities, Paul A. Bosela, D. R. Ludwiczak

Civil and Environmental Engineering Faculty Publications

Space structures, due to economic considerations, must be light-weight. Accurate prediction of the natural frequencies and mode shapes is critical for determining the structural adequacy of components, and designing a control system. The total stiffness of a member, in many cases, includes both the elastic stiffness of the material as well as additional geometric stiffness due to pre-load (initial stress stiffness). The pre-load causes serious reservations on the use of standard finite element techniques of solution. In particular, a phenomenon known as ''grounding'', or false stiffening, of the stiffness matrix occurs during rigid body rotation. The author has previously shown …