Soil Science 150 mcq
sandy soils typically have low porosity, high saturated hydraulic conductivity
clay soils have strong suction (large magnitude of matric head)
field capacity is defined at matric head -340 cm
around
wilting point is defined at matric head -15000
around
porosity is highest in clay
which soil has the higher saturated sand
hydraulic conductivity
hydraulic conductivity decreases most sand
sharply w/ drying in
suction head becomes more negative water content decreases
as
a soil at field capacity is finished draining gravitationally
matric head in unsaturated zone is negative
, Soil Science 150 mcq
as water content becomes saturated θ matric head approaches 0
→ θs (soil becomes wet), how does
matric head change
as soil dries, how does hydraulic hydraulic conductivity (K) decreases
conductivity change
what does the brooks corey parameter curve steepness
b control
where does this equation come from piezometric head decomposition
ψ(z) = h(z) − z
if matric head becomes more negative water content decreases upward
w/ height in column, how does water
content change
water moves from higher water content to lower water content
capillary forces drive flow from wet to dry
If hydraulic head gradient dh/dz = 0 q = 0 (darcy's flux)
High suction gradients (large |ψ|) are upward flow
needed for:
before ponding, infiltration rate equals P (precipitation)
sandy soils typically have low porosity, high saturated hydraulic conductivity
clay soils have strong suction (large magnitude of matric head)
field capacity is defined at matric head -340 cm
around
wilting point is defined at matric head -15000
around
porosity is highest in clay
which soil has the higher saturated sand
hydraulic conductivity
hydraulic conductivity decreases most sand
sharply w/ drying in
suction head becomes more negative water content decreases
as
a soil at field capacity is finished draining gravitationally
matric head in unsaturated zone is negative
, Soil Science 150 mcq
as water content becomes saturated θ matric head approaches 0
→ θs (soil becomes wet), how does
matric head change
as soil dries, how does hydraulic hydraulic conductivity (K) decreases
conductivity change
what does the brooks corey parameter curve steepness
b control
where does this equation come from piezometric head decomposition
ψ(z) = h(z) − z
if matric head becomes more negative water content decreases upward
w/ height in column, how does water
content change
water moves from higher water content to lower water content
capillary forces drive flow from wet to dry
If hydraulic head gradient dh/dz = 0 q = 0 (darcy's flux)
High suction gradients (large |ψ|) are upward flow
needed for:
before ponding, infiltration rate equals P (precipitation)
