CE 403 Optional FE Review:
Hydraulics and Hydrologic Systems
Chris Rehmann
Hydraulics and hydrologic systems
A. Basic hydrology (e.g., infiltration, rainfall,
runoff, detention, flood flows, watersheds)
B. Basic hydraulics (e.g., Manning equation,
Bernoulli theorem, open-channel flow,
pipe flow)
C. Pumping systems (water and wastewater)
D. Water distribution systems
E. Reservoirs (e.g., dams, routing, spillways)
F. Groundwater (e.g., flow, wells, drawdown)
G. Storm sewer collection systems
Basic hydrology: Example 1
A 5-acre catchment experiences a 2-h storm
with a rainfall depth of 1 in. If the runoff
coefficient is 0.4, the runoff in ft3/s is most
nearly
A.
B.
C.
D.
0.4
1.0
2.0
2.5
Basic hydrology: Example 2
A storm sewer is to be designed for an urban
catchment with area 2000 m2 and runoff coefficient of
0.8. The catchment has a time of concentration of 30
min, and rainfall data is shown below. The runoff in
m3/s is most nearly
A.
B.
C.
D.
8.9 x 10-3
1.1 x 10-2
8.9 x 10-1
3200
Basic hydrology: Example 3
A 5-acre catchment experiences a 2-h storm
with a rainfall depth of 3 in. If the curve number
is 50, the runoff in inches is most nearly
A.
B.
C.
D.
0.1
0.2
3.0
375
Basic hydrology: Example 4
A.
B.
C.
D.
0.0003
0.28
1.00
3.33
Flow (cfs)
A watershed with area 12,000 ft2 has the hydrograph
below. The value of the peak flow (in cfs) that makes it
a unit hydrograph (corresponding to 1 in of rainfall)
most nearly is
?
0
2
0.5
Time (h)
Basic hydraulics: Çengal & Cimbala #20.2
Basic hydraulics: White #FE10.5
Consider an open rectangular channel 3 m wide laid on a 1° slope.
If Manning’s roughness factor is 0.02 and the flow is 24.6 m3/s,
what is the normal depth?
a.
b.
c.
d.
e.
1m
1.5 m
2m
2.5 m
3m
Basic hydraulics: White #FE10.6
Consider an open rectangular channel 3 m wide laid on a 1° slope.
If Manning’s roughness factor is 0.02 and the flow is 24 m3/s, what
is the critical depth?
a.
b.
c.
d.
e.
1m
1.26 m
1.5 m
1.87 m
2.0 m
Basic hydraulics: Ç&C #13.1
Basic hydraulics: White #FE6.6
A smooth 8-cm-diameter pipe, 200 m long, connects two
reservoirs, containing water at 20°C, one of which has a surface
elevation of 700 m and the other with its surface elevation at 560
m. If minor losses are neglected, the expected flow rate through
the pipe is
a.
b.
c.
d.
e.
0.048 m3/h
2.87 m3/h
134 m3/h
172 m3/h
385 m3/h
Pumping systems: Example 5
A pump delivers water at 0.1 m3/s with a head of 20 m. The power
required is 28,000 W. The efficiency of the pump is most nearly
A.
B.
C.
D.
60%
65%
70%
75%
Pumping systems: Gupta ex. 11.18
21
26
32
42
1 hp = 33,000 ft lb/min
1 gal = 0.134 ft3
150
140
130
120
110
100
90
80
70
60
50
40
30
20
10
0
Efficiency
70
60
Pump characteristic
curve
50
40
30
System curve
20
10
0
0
200 400 600 800 1000 1200 1400 1600 1800
Flow rate (gpm)
Efficiency (%)
A.
B.
C.
D.
Head (ft)
The characteristic curve and efficiency for a pump are shown below
with the system curve for water. The power required in hp is most
nearly
160
80
Water distribution systems: Ex. 7
Two concrete pipes flow in parallel. Both are 200 m long. Pipe 1 has
a diameter of 0.3 m and a roughness length of 3 mm, while pipe 2
has a diameter of 0.45 m and a roughness length of 0.9 mm. The
head loss between the two junctions is 0.5 m. The fraction of the
total flow carried by pipe 1 is most nearly
A.
B.
C.
D.
11%
22%
44%
66%
Reservoirs: Example 8
The outlet structure for a basin with a width of 30 m is a 90° Vnotch weir. When the head is 0.5 m over the weir, the discharge in
m3/s is most nearly
A.
B.
C.
D.
0.25
0.45
3.13
19.5
Groundwater: FE SRH 3
A confined aquifer of width 750 m and thickness
20 m has a conductivity of 1 m/d. Piezometers
spaced 340 m apart yield heads of 35 m and 33
m. What is the flow in this aquifer?
a.
b.
c.
d.
88 m3/d
93 m3/d
15,000 m3/d
29,920 m3/d
FE SRH = F.E. Supplied Reference Handbook (2008)
Groundwater: Example 9
A confined aquifer of width 750 m and thickness 20 m
has a conductivity of 1 m/d and porosity of 0.25.
Piezometers spaced 340 m apart yield heads of 35 m
and 33 m. The travel time between the piezometers in
years is most nearly
a.
b.
c.
d.
0.04
3.9
40
158
Groundwater: FE SRH 4
A pump test in an unconfined aquifer is conducted,
and the well is pumped at 150 m3/d. Drawdowns
measured 50 m and 100 m from the well are 5 m
and 1.5 m, respectively. The water table before
pumping is 36 m above the aquifer bottom. What is
the hydraulic conductivity?
a.
b.
c.
d.
0.02 m/d
0.14 m/d
0.52 m/d
1.81 m/d
Storm sewers: Example 10
If the roughness coefficients are assumed to be
constant, maximum flow in a pipe will occur when
the depth is most nearly what fraction of the
diameter?
A.
B.
C.
D.
80%
92%
100%
110%