نتایج جستجو برای: surficial aquifer
تعداد نتایج: 9219 فیلتر نتایج به سال:
Peat and organic soils commonly occur as extremely soft, unconsolidated surficial deposits that are an integral part of the wetland systems. They may also occur as strata beneath other surficial deposits. These soils are problematic as they are very highly compressible and are of very low shear strength. In countries like Malaysia, peat and organic soils are found in abundance. Utilization of t...
Initial sampling results of emerging contaminants at the Llobregat delta deep aquifer (Barcelona, Spain) are presented. Among micro contaminants selected are 82 pharmaceuticals (antibiotics, lipid regulation agents, analgesic/anti-inflammatory drugs, etc), 18 personal care products (sunscreen agents, preservatives and disinfectants/antiseptics), 4 metals, 44 pesticides, 6 volatile priority poll...
An approximation is obtained for the recession of a sloping aquifer. The analytical approximation can provide a useful tool to analyze data and obtain physical properties of the aquifer. In contrast to the case of a horizontal aquifer, when plotting the time derivative of the flux versus the flux on a log scale, the result shows that the flux derivative reaches a minimum value and that the curv...
Regional nitrate and pesticide trends in ground water in the eastern San Joaquin Valley, California.
Protection of ground water for present and future use requires monitoring and understanding of the mechanisms controlling long-term quality of ground water. In this study, spatial and temporal trends in concentrations of nitrate and pesticides in ground water in the eastern San Joaquin Valley, California, were evaluated to determine the long-term effects of agricultural and urban development on...
Transmissivity is an important hydraulic parameter to determine the amount of water passed horizontally across a given saturated thickness of an aquifer. The techniques to quantify this parameter, such as grain size analyses or pumping tests, can have limitations of time/spatial scale, viability, or economically. One technique that can be used, but little adopted, is the capture zone analysis. ...
[1] The Martian outflow channels were carved by the eruption of catastrophic floods from groundwater aquifers. This study models the time evolution of a typical outflow channel flood originating within a chaos region. The flood initiates when superlithostatic pore pressures within a confined aquifer lead to the propagation of hydrofractures through the confining cryosphere to the surface. The p...
A shallow aquifer with different redox zones overlain by intensive agricultural activity was monitored for the occurrence of 1,2-dichloropropane (DCP) to assess the fate and origin of this pollutant. DCP was detected more frequently in groundwater samples collected in aerobic and nitrate-reducing zones than those collected from iron-reducing zones. Simulated DCP concentrations for groundwater e...
The conditions in which groundwater inflow occurs boreal peatlands and its contribution to peatland water balance are still poorly understood. objectives of this research were quantify the hydrological connectivity between a surficial aquifer peatland, identify controlling factors north-central Quebec (Canada). instrumented with piezometers levels monitored during two growing seasons. Hydraulic...
A field investigation of a TCE plume in a surficial sand aquifer shows that groundwater-surface water interactions strongly influence apparent plume attenuation. At the site, a former industrial facility in Connecticut, depth-discrete monitoring along three cross-sections (transects) perpendicular to groundwater flow shows a persistent VOC plume extending 700 m from the DNAPL source zone to a m...
Depletion and consequently reduction in groundwater storage results in numerous harmful environmental effects such as reduction in yields of wells, land subsidence, lowering of water quality and also reduction in storage of surface water bodies having hydraulic relation with aquifers. In this research, groundwater depletion in the Najafabad subcatchment aquifer located in the GavKhouni basin, I...
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