"Three-dimensional Bayesian geostatistical aquifer characterization at the Hanford 300 Area using tracer test data" (2012). US Department of Energy Publications. Paper 309. [1] Tracer tests performed under natural or forced gradient flow conditions can provide useful information for characterizing subsurface properties, through monitoring, modeling, and interpretation of the tracer plume migrat...

[1] Most analytical and numerical models developed to analyze pumping test data focus on saturated flow below the water table. Traditionally the soil above the initial water table prior to pumping has been thought to have little influence on the test results and has usually been ignored. It is hypothesized that, if the unsaturated zone is capped by low-permeability soil, airflow in the unsatura...

The Afghanistan population living far from rivers relies upon groundwater delivered from karezes (sub-horizontal tunnels). Karezes exploit unconfined groundwater in alluvial fans recharged largely by snowmelt from the Hindu Kush, the central mountain range of the country. Since the multi-year drought that began in 1998, many karezes have stopped flowing. This study characterizes the hydraulics ...

Hydrologic changes associated with the 17 January 1995 Kobe Earthquake occurred in Awajishima Island very close to the epicenter. These included: (1) large drop of water table in the mountainous area; (2) rapid increase of discharge along active faults; and (3) change of chemistry of discharged water. A simple horizontal flow model was constructed to explain the observed changes; and optimal se...

We present a methodology to account for the stochastic nature of hydraulic conductivity during the design of pump-and-treat systems for aquifer cleanup. The methodology (I) uses a genetic algorithm to find the global optimal solution and (2) incorporates a neural network to model the response surface within the genetic algorithm. We apply the methodology for a real example and different optimiz...

A combination of subsurface borehole imaging data and drilling logs were used to characterize the fractures and lithology in 40 bedrock wells at the fractured-rock research site in the Mirror Lake area in Grafton County, New Hampshire. The purpose of the research was to determine whether subsurface lithology and fractures have an effect on the hydraulic conductivity of the crystalline-rock aqui...

SEAWAT and the Sea Water Intrusion (SWI) Package for MODFLOW were used to simulate hypothetical aquifer storage and recovery (ASR) scenarios under constantand variable-density conditions. To test the codes, both models were used to represent two-dimensional axisymmetric groundwater flow near an ASR well. The models were “tricked” into representing axisymmetric flow by multiplying the input valu...

Leakage rates are evaluated for a landfill barrier system having a compacted clay liner (CCL) underlain by a vadose zone of variable thickness. A numerical unsaturated flow model SEEP/W is used to simulate the moisture flow regime and steady-state leakage rates for the cases of unsaturated zones with different soil types and thicknesses. The results of the simulations demonstrate that harmonic ...

The characterization of a heterogeneous aquifer involves a wide spectrum of high resolution direct measurements of the characteristic parameters, defined in itinere according to the various approaches used. This information is usually obtained from the pumping tests and the relative measurements of the drawdown induced. Unfortunately, these methods are intrusive and the hydrological system is p...

background: groundwater nitrate pollution is an important environmental problem in water resources management. in this regard, specific measures aiming at prevention of water pollution will be helpful to managers and decision-makers. identification of aquifers’ vulnerable areas and determination of groundwater protection zones using most widely used models, such as drastic and cd, are one of th...