Geophysical site characterization investigations at fuel spill sites have been generally guided by a working hypothesis Ž . which assumes that the light non-aqueous phase liquids LNAPL are a fully saturating phase of intrinsically very high electrical resistivity. Using observations from other related sciences, and contrary geophysical observations, a different model is developed which treats t...

At the regional scale, vadose-zone processes are recognized for controlling both short-term dynamics in watershed hydrology and long-term water balances of hydrologic basins. In this paper we explore the various conceptual and mathematical models that have been proposed or could be considered to represent water fluxes in the vadose zone at the catchment, watershed or regional scale. Such models...

Leaking underground concrete sumps used to store produced water have contaminated groundwater with gas condensate hydrocarbons at a gas production site near Ft. Lupton, Colorado. The source of contamination has been removed; however, a plume of hydrocarbon contamination extends some 46 m from the original source location. This is an agricultural area and the water table is rather shallow (about...

Barometric pressure changes can induce airflow in an open borehole or well screened in the vadose zone, thereby ventilating the soil surrounding the borehole. This paper presents an analytic model of the induced airflow and compares the predictions of the model with experimental measurements. This model may be useful for the design of passive soil vapor extraction as applied to the remediation ...

Soil nitrate is important for crop growth, but it can also leach to groundwater causing nitrate contamination, a threat to human health. Here, we report a significant accumulation of soil nitrate in Chinese semi-humid croplands based upon more than 7000 samples from 141 sites collected from 1994 to 2015. In the 0-4 meters depth of soil, total nitrate accumulation reaches 453 ± 39, 749 ± 75, 119...

Long-term dewatering of groundwater is a necessary operation for mining safety in open-pit coal mines, as extensive might cause ecological problems due to dramatic changes moisture movement the soil, especially ecologically fragile areas. In order evaluate impact on vadose zone and vegetation, this paper presents quantitative methodology takes Baorixile mine study example. A long-term situ expe...