What factors in the vadose zone might influence the movement of contaminants?
The migration times and concentrations of the groundwater contaminants are also affected by the convection, dispersion, adsorption and biodegradation of the contaminants in the vadose zone. The pollution sources and contaminants should be factored into the groundwater specific vulnerability.
What is vadose zone filled with?
The vadose zone has low water content relative to the saturated zone below the water table and is therefore commonly referred to as the unsaturated zone. Above the capillary fringe, vadose-zone pore spaces are generally air-filled, with thin water films coating solid particles.
Is vadose zone saturated?
The vadose zone is the undersaturated portion of the subsurface that lies above the groundwater table. The soil and rock in the vadose zone are not fully saturated with water; that is, the pores within them contain air as well as water.
What is the function of vadose zone?
The vadose zone is known to play a critical role within the biosphere: (1) as a storage medium to supply water to the plants and atmosphere, and (2) as a controlling agent in the transmission of recharging water as well as contaminants from the land surface to groundwater (Nimmo 2005).
Is vadose zone unsaturated?
The vadose zone, also termed the unsaturated zone, extends from the top of the ground surface to the water table. The word Vadose means “shallow” in Latin.
Why does groundwater discharge to Earth’s surface?
the water table would not exist. Why does groundwater discharge to Earth’s surface? Earth’s surface is irregular, and permeability decreases with depth within Earth.
What is meant by vadose water?
Vadose water is subsurface water between the land surface and the saturated zone below the water table. The vadose (or unsaturated) zone includes soil water, which is immediately available to the biosphere.
Where does groundwater discharge naturally?
Groundwater discharge is the term used to describe the movement of groundwater from the subsurface to the surface. There is natural discharge which occurs into lakes, streams and springs as well as human discharge, which is generally referred to as pumping.
What are the 3 zones of groundwater?
Water beneath the surface can essentially be divided into three zones: 1) the soil water zone, or vadose zone, 2) an intermediate zone, or capillary fringe, and 3) the ground water, or saturated zone.
What is the correct term for the boundary between vadose water and groundwater?
The boundary between the vadose zone and the saturated zone is not a uniformly distinct one, because the water table can rise or fall depending on rainfall events. The area that makes up this somewhat diffuse boundary is called the capillary fringe (Figure 4.3).
What is vadose water?
What is the relationship between groundwater pollution and the vadose zone?
There is an intimate connection between the pollution of groundwater and the vadose zone. Special attention is given here to calculations of overall mass budgets and flux balance of pollutants for the evaluation of phreatic aquifer contamination due to its use as a source of water for human populations.
What is a vadose zone?
Definition of the Vadose Zone. The vadose zone is the Earth’s terrestrial subsurface that extends from the surface to the regional groundwater table.
What is the law of vadose?
The law is used to mathematically describe the flow of groundwater and infiltration through the vadose zone ( Bowen, 1986 ). Sampling groundwater and water in the vadose zone is more technically demanding than sampling streams or lakes. To sample water from the va-dose zone, lysimeters are used ( Fig. 4.6 ).
How does evaporation affect residual gasoline in the vadose zone?
The effect of evaporation on residual gasoline in the vadose zone occurs in a predictable manner that is largely a function of the vapor pressure of each compound and the temperature (see Gasoline Weathering section).