In hydrogeology, groundwater flow is defined as the "...part of streamflow that has infiltrated the ground, has entered the phreatic zone, and has been discharged into a stream channel, via springs or seepage water". It is governed by the groundwater flow equation. Groundwater is water that is found underground in cracks and spaces in the soil, sand and rocks. An area where water fills these spaces is called a phreatic zone or saturated zone. Groundwater is stored in and moves slowly through the layers of soil, sand and rocks called aquifers. The rate of groundwater flow depends on the permeability (the size of the spaces in the soil or rocks and how well the spaces are connected) and the hydraulic head (water pressure).
- Subsurface flow
- Groundwater energy balance
- Preferential Flow
Preferential Flow Study
Vertical flow of solute in porous media (preferential flow) is studied and compared with Darcy's flow. The methodology used for the study is experimental. The laboratory model used is similar to Darcy apparatus with slight modification. The study has compare measured velocity of first reach of solute with average velocity of flow in porous media. The laboratory model consists of 150 mm diameter High density Polyethylene pipe of 750 mm height filled uniform sand. Nine sets of experiment is conducted with 3 types of sand (D10= 0.6 mm and Cu1.42, D10= 0.11 mm and Cu1.55, D10= 0.3 mm and Cu1.4) and 3 types of brine concentration (5%, 10%, 20% by weight brine solution). Brine solution is found to be 1.13 to 1.84 times faster than average velocity of flow as a result of preferential flow.
- Chorley, R.J., 1978. Glossary of Terms. In: M.J. Kirkby (Ed), Hillslope Hydrology, John Wiley and Sons, Chichester, U.K.: 1-42