ASBOG Exam with Accurate Solutions
Aquifer - correct Answer-water bearing geological formation that can store and transit
usable amounts of water. high porosity, and permeability
aquitard - correct Answer-somewhat restricts water movement
aquiclude - correct Answer-layer that completely prevents water movement
unconfined aquifer - correct Answer-top is water table, recharged by local rainfall,
generally freshwater, cheap to drill wells, easily contaminated, potentiometric
surface=water table
confined aquifer - correct Answer-top is a confining layer, can be artesian wells,
potentiometric surface is generally above the physical top, in or above confining layer,
recharged by distant water
b - correct Answer-saturated thickness
s (drawdown) - correct Answer-change in potentiometric surface in response to
pumping a well
porosity (phi) - correct Answer-amount of empty space in a solid object (n=Vvoid/Vtotal)
porosity equations - correct Answer-Vv/Vt, Vt-Vs/Vt, 1- Vs/Vt, 1-
drybulkdensity/particledensity
porosity depends on - correct Answer-packing, grain shape, grain size, grain size
distribution, structure, density, moisture content, effective porosity, permeability, specific
yeild
specific gravity - correct Answer-density of substance/density of water
bulk density - correct Answer-overall density of rock including water in it. always less
than density of rock because water density is less
gravimetric moisture content (w) - correct Answer-weight h20/ weight solids
volumetric water content (theta) - correct Answer-volume h20/vol total
saturation (S) - correct Answer-volume water/volume voids
, effective porosity - correct Answer-porosity available for fluid flow. always less than total
porosity
permeability - correct Answer-measures the transmission property of the media and
interconnection of the pores
Dupuit assumption - correct Answer-when the slope of water table is negligibly small,
assume equipotentials are vertical, flowlines are horizontal. workes with shallow
unconfined flow
heterogeneity - correct Answer-hydraulic conductivity is not the same in different spots
of the aquifer
3 types of heterogeneity - correct Answer-random(finescales), structured(river deltas),
layered(sed basin)
horizontal hydraulic conductivity - correct Answer-arithmetic mean: Keff= sum of
(kib)/sum of b
vertical hydraulic conductivity - correct Answer-harmonic mean: Keff = sum of b/ sum of
(b/Ki)
snells law - correct Answer-k1/k2 = tan(α1)/tan(α2)
lines closer together on contour maps - correct Answer-lower K
lines further apart on contour maps - correct Answer-higher K
anisotropy - correct Answer-hydraulic conductivity is different in different directions
anisotropy causes - correct Answer-layering at a scales less than interested in;
preferential orientation of effective porosity
types of wells - correct Answer-dug, driven, bored(used as storage), drilled
drawdown over time - correct Answer-increases
effect of lower transmissivity on drawdown - correct Answer-narrower, deeper cone of
depression
effect of lower storativity/specific yeild on drawdown - correct Answer-shifts whole cone
deeper. confined usually have bigger cones bc Ss << Sy
specific yeild (Sy) - correct Answer-volume fraction of water that drains from a saturated
rock under influence of gravity
Aquifer - correct Answer-water bearing geological formation that can store and transit
usable amounts of water. high porosity, and permeability
aquitard - correct Answer-somewhat restricts water movement
aquiclude - correct Answer-layer that completely prevents water movement
unconfined aquifer - correct Answer-top is water table, recharged by local rainfall,
generally freshwater, cheap to drill wells, easily contaminated, potentiometric
surface=water table
confined aquifer - correct Answer-top is a confining layer, can be artesian wells,
potentiometric surface is generally above the physical top, in or above confining layer,
recharged by distant water
b - correct Answer-saturated thickness
s (drawdown) - correct Answer-change in potentiometric surface in response to
pumping a well
porosity (phi) - correct Answer-amount of empty space in a solid object (n=Vvoid/Vtotal)
porosity equations - correct Answer-Vv/Vt, Vt-Vs/Vt, 1- Vs/Vt, 1-
drybulkdensity/particledensity
porosity depends on - correct Answer-packing, grain shape, grain size, grain size
distribution, structure, density, moisture content, effective porosity, permeability, specific
yeild
specific gravity - correct Answer-density of substance/density of water
bulk density - correct Answer-overall density of rock including water in it. always less
than density of rock because water density is less
gravimetric moisture content (w) - correct Answer-weight h20/ weight solids
volumetric water content (theta) - correct Answer-volume h20/vol total
saturation (S) - correct Answer-volume water/volume voids
, effective porosity - correct Answer-porosity available for fluid flow. always less than total
porosity
permeability - correct Answer-measures the transmission property of the media and
interconnection of the pores
Dupuit assumption - correct Answer-when the slope of water table is negligibly small,
assume equipotentials are vertical, flowlines are horizontal. workes with shallow
unconfined flow
heterogeneity - correct Answer-hydraulic conductivity is not the same in different spots
of the aquifer
3 types of heterogeneity - correct Answer-random(finescales), structured(river deltas),
layered(sed basin)
horizontal hydraulic conductivity - correct Answer-arithmetic mean: Keff= sum of
(kib)/sum of b
vertical hydraulic conductivity - correct Answer-harmonic mean: Keff = sum of b/ sum of
(b/Ki)
snells law - correct Answer-k1/k2 = tan(α1)/tan(α2)
lines closer together on contour maps - correct Answer-lower K
lines further apart on contour maps - correct Answer-higher K
anisotropy - correct Answer-hydraulic conductivity is different in different directions
anisotropy causes - correct Answer-layering at a scales less than interested in;
preferential orientation of effective porosity
types of wells - correct Answer-dug, driven, bored(used as storage), drilled
drawdown over time - correct Answer-increases
effect of lower transmissivity on drawdown - correct Answer-narrower, deeper cone of
depression
effect of lower storativity/specific yeild on drawdown - correct Answer-shifts whole cone
deeper. confined usually have bigger cones bc Ss << Sy
specific yeild (Sy) - correct Answer-volume fraction of water that drains from a saturated
rock under influence of gravity
