groundwater midterm

example of unconsolidated porous

sand, gravel, silt, clay, fluvial, marine, aeolian

consolidated media

fractured rock (limestone, metamorphic)

total porosity

void volume over total volume

particle mass density equation

mass of solid divided by volume of solids (Ms/Vs)

bulk density equation

mass of solids divided by total volume (Ms/Vt)

unsaturated zone volumetric moisture content

thetaw < nT

saturated media moisture content

thetaw = nT

definition of porous media

a matrix of solid or unconsolidated material consisting of interconnected pores through which liquid or gas may travel

pressure head

from perforated pipe to top of water in pipe

hydraulic head

pressure head plus elevation

hydraulic gradient

determines the rate of flow and direction of flow

three elements that control flow in a GW system

climate, topography, and geology

darcy’s experiment found

linear trend between flow, Q, and gradient

hydraulic conductivity is a property of

media and fluid

average linear velocity is used for

calculation of travel time of dissolved substances

above water table, thetaw and Pw

thetaw < n, pw<0

at water table

p = 0

below water table

thetaw = n, p>0

in a heterogenous aquifer

intrinsic permeability (k) and hydraulic conductivity (K) varies with space

in a homogenous aquifer

intrinsic permeability and K is uniform and considered a constant with respect to space

hydraulic conductivity distribution

statistical measures are used to scale observed K values in heterogeneous aquifers

transmissivity def

aquifer property for quantifying the volumetric rate of horizontal or radial flow

transmissivity equation

full thickness of aquifer x hydraulic conductivity

vertical K tends to be ____ ___ than horizontal K

much less

anisotropic aquifer def

intrinsic permeability (k) and hydraulic conductivity (K) are dependent on direction

isotropic aquifer def

intrinsic permeability and K is the same in all directions

hydraulic conductivity based on grain size distribution equation

Kozeny-Carmen from Bear (1972), and Shepard (1989)

layered media average K assumptions

each layer homogenous and isotropic, flow perpendicular to layers is constant and uniform, flow parallel to layers is different in each layer but hydraulic gradient is the same in each layer

volumetric moisture content equation

Volume of water / Total volume of soil (including solids and air pores) (Vwater/Vt), always less than or equal to nT

slope of darcy’s graph (flow vs gradient)

hydraulic conductivity

total porosity equation

1 - (bulk density/particle mass density)

void volume equation

total volume - volume of solids (Vt - Vs)