Typically, when a new subsurface flow and transport problem is first being considered, very simple models with a minimal number of parameters are used to get a rough idea of how the system will evolve. For a hydrogeologist considering the spreading of a contaminant plume in an aquifer, the aquifer thickness, porosity, and permeability might be enough to get started. If the plume is buoyant, aqu...

A rule of thumb is presented to determine where variations in the discharge of a pumping well have a significant influence on the flow in an aquifer. The rule of thumb relates the period of the variation of the discharge to the distance from the well beyond which the transient effect on the flow in the aquifer is insignificant. For example, when an irrigation well pumps intermittently during th...

The release of colloids to groundwater was investigated in situ in an ironoxyhydroxide-rich, sandy aquifer. Groundwater amended with various solutes was injected into and immediately withdrawn from the shallow aquifer. Turbidity and colloid composition were monitored in the retrieved injectate. The response of the aquifer material to the amendments generally mimicked that observed in an earlier...

A head loss concept, new to the stream-aquifer interaction, is introduced for modeling laboratory observations. Using this concept, the equation applicable to fully penetrating streams is modified to account for the head loss at the entrance. The modified model is able to explain and fit the observed laboratory data correctly. Equations are proposed to calculate the hydraulic diffusivity of aqu...

Horizontal Permeability kh m 1.5×10 [10] 9×10 [10] 10 [1] Specific Storage SS m 5×10 [8] 2.7×10 [9] 10 [1] Aquifer Head h@t=0 m 0 [6] 130 [6] 5×10 [18] Aquifer Depth D m 55 [7] 2000 [6] 5×10 [1] Aquifer Thickness H m 16 [5] 3×10 [6] 5×10 [18] Kinematic Viscosity ν m/s 0.658×10 [2] 1.78×10 [2] 1.5×10 [18] Fissure Width w m N/A N/A 2.0 [1] Manning’s Number n None 0.012 [2] 0.05 [2] 0.04 [15] PARA...

A laboratory experiment was conducted to demonstrate the behavior of dense nonaqueous phase liquid (DNAPL) 1,1,1-trichloroethane (TCA) in a complex aquifer system. The system simulated consists of two unconfined aquifers separated by a low permeable bedrock perching layer that contains a fracture. In contrast to previous work by other researchers of DNAPL migration in hydrostatic conditions, in...

Near surface groundwater contamination is a widespread problem. The potential for contamination of deep aquifers in such areas depends on the vertical hydraulic gradient as well as the extent and location of interconnection between the upper and lower aquifers. In alluvial~ sedimentary environments, the geologic units are typically weakly connected lenses or layers of high or low conductivity w...

Compartmentalisation, the subdivision of an aquifer into discrete and relatively isolated units, may be of critical importance for the protection of groundwater although it has been largely ignored in the groundwater literature. The Lower Triassic Sherwood Sandstone, in north west of England, UK, may be a good example of an aquifer that has been compartmentalised by numerous high angle faults w...

Background The presence of nitrate is one of the factors limiting the quality of groundwater resources, particularly in arid and semi-arid climates. Therefore, the knowledge about the distribution of nitrate in groundwater and its source has an effective role in protecting health. The study aimed to optimize an interpolation method to predict the nitrate concentration and assessment of aquifer ...