問題一覧
1
the ratio of the cross-sectional area of fluid flow, A, to the length of the wetted perimeter.
hydraulic radius
2
what are the two standard laboratory tests that are used to determine the hydraulic conductivity of soil.
constant-head test and falling-head test
3
it controls the amount of fluid discharge of a channel and its ability to move sediments. This is a measure of channel flow efficiency.
hydraulic radius
4
The total volume of water collected may be expressed as:
done
5
factors affecting flow of permeability: page 13
done
6
the total head at a point in water under motion can be given by the sum of the pressure, velocity, and elevation heads. the total head at a point in water under motion can be given by the sum of the pressure, velocity, and elevation heads.
bernoulli’s equation
7
In ____, Darcy published a simple equation for the discharge velocity of water through saturated soils, which may be expressed as ____.
1856, v=ki
8
typical values of hydraulic conductivity of saturated soils.
done
9
indicates that adjacent paths of water particles are parallel, even when changing direction, and the paths never cross.
laminar flow
10
it is the study of the groundwater phase of the hydrologic cycle (both surface and subsurface) related to the effects of geophysical features of soil and rock formations.
hydrogeology
11
is a physical property which measures the ability of the material to transmit fluid through pore spaces and fractures in the presence of an applied hydraulic gradient.
hydraulic conductivity
12
read the importance of hydrogeology
done
13
may be either relatively stationary or mobile (that is, underground flow is occurring)
groundwater
14
tends to reflect the surface topography of the area, being at higher elevation where the ground surface is high and at a lower elevation where the ground surface is low.
water table or phreatic surface
15
Soils are _____ due to the existence of interconnected voids through which water can flow from points of high energy to points of low energy.
permeable
16
the ability of water (or other fluid) to flow through a soil by traveling through the void spaces.
permeability
17
In this type of laboratory setup, the water supply at the inlet is adjusted in such a way that the difference of head between the inlet and the outlet remains constant during the test period.
constant-head test
18
Water from a standpipe flows through the soil. The initial head difference h1 at time t = 0 is recorded, and water is allowed to flow through the soil specimen such that the final head difference at time t = t2 is h2.
falling-head test
19
One of the major physical parameters of a soil that controls the rate of seepage through it is hydraulic conductivity,
permeability
20
it is the cycle of changes and movements that surface water and shallow groundwater repeatedly passes through.
hydrologic cycle
21
snow or rain that reaches the earth's surface tends to either flow over the ground surface as dictated by gravity or to infiltrate into the ground.
precipitation
22
formula of hydraulic radius, Rh
done
23
The rate of flow of the water through the specimen at any time t can be given by:
done
24
soil zone above the phreatic surface, pore water pressure is negative.
vadose zone
25
hydraulic conductivity depends on several factors: page 11
done
26
infiltrating water that continue to migrate due to gravity effects is drawn to the underground zone.
infiltration
27
Most soils are not isotropic with respect to permeability. In a given soil deposit, the magnitude of _ changes with respect to the direction of flow.
k