A new inverse method is developed to simultaneously estimate heterogeneous hydraulic conductivities, source/sink rates, and unknown boundary conditions for steadystate flow in an unconfined aquifer. Unlike objective function-based techniques, the new method does not optimize any data-model misfits. Instead, its formulation is developed by honoring physical flow principles as well as observation...

withdrawal of oil and gas from reservoirs causes a decrease in pore pressure and an increase in effective stress which results to a reservoir compaction. reservoir compaction will result in surface subsidence through the elastic response of the subsurface. usually in order to determine the subsidence above a hydrocarbon field, the reservoir compaction must be first calculated and then the effec...

Proposed withdrawal of groundwater from the surficial aquifer system confined zone, or the upper and lower Brunswick aquifers in eastern Camden County, Georgia, could result in drawdown extending beneath the Cumberland Sound and potentially could affect groundwater levels and natural resources at Cumberland Island National Seashore. Using a nonequilibrium formula, estimated drawdown after 5 yea...

Modeling and calibration of natural aquifers with multiple scales of heterogeneity is a challenging task due to limited subsurface access. While computer modeling plays an essential role in aquifer studies, large uncertainty exists in developing a conceptual model of an aquifer and in calibrating the model for decision making. Due to uncertainties such as a lack of understanding of subsurface p...

A novel methodology for the interpretation of pumping tests in leaky aquifer systems, referred to as the double inflection point (DIP) method, is presented. The method is based on the analysis of the first and second derivatives of the drawdown with respect to log time for the estimation of the flow parameters. Like commonly used analysis procedures, such as the type-curve approach developed by...

The Abbotsford-Sumas Aquifer is a shallow, predominantly unconfined aquifer that spans regions in southwestern British Columbia, Canada and northwestern Washington, USA. The aquifer is prone to nitrate contamination because of extensive regional agricultural practices. A 22-month ground water nitrate assessment was performed in a 10-km2 study area adjacent to the international boundary in north...

Three indigenous groundwater bacterial strains and Pseudomonas putida harboring plasmids TOL (pWWO) and RK2 were introduced into experimentally contaminated groundwater aquifer microcosms. Maintenance of the introduced genotypes was measured over time by colony hybridization with gene probes of various specificity. On the basis of the results of colony hybridization quantitation of the introduc...

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. iii Figures 1-4. Maps showing: 1. Study area, regions within the study area, and all well...

Understanding the mechanisms of DNA compaction is becoming increasingly important for gene therapy and nanotechnology DNA applications. The kinetics of the compaction velocity of single DNA molecules was studied using two non-protein condensation systems, poly(ethylene glycol) (PEG) with Mg(2+) for the polymer-salt-induced condensation system and spermine for the polyamine condensation system. ...

Soil compaction by machine used in forest harvesting operation caused negative impacts for regeneration and tree growth. This research was intended to analyze the effectiveness of using slash to decrease soil compaction, to analyze soil compaction at various soil depths, and to measure rut depth at soil surface. Valmet 860.1 forwarder was used in this research. Soil compaction was measured thro...