Geol 454

hydraulic conductivity

measure the ease of water flow through a porous medium analogous to resistance

hydraulic head

the total mechanical potential energy per weight of water

piezometer

well with very short screen used to measure hydraulic head and collect water samples

homogeneous

k is the same in all locations

heterogeneous

k varies in all locations

isotropic

k is the same in all directions

anisotropic

k varies with direction

heterogeneity & anisotropy

results in the environment of deposition of a geologic unit and all post-depositional processes which modified the unit

limits to darcy's law

1. measured k is not represented
2. breaks down at extremely high and low flow rates
3. k representative averaged over and area & reynolds number

aquifer

geologic unit which can store & transmit water to a pumping well

aquitard

layer of very low permeability material which can store & transmit water slowly from one aquifer to another