University of Dohuk Final Examination Subject: Irrigation systems
College of Agricultural 1st semester
Engineering Sciences 2023 - 2024 Class : Forth
Dept. of Soil & water sciences Type B Time : 3 hours
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QI)
a. What are the most common benefits of water reservoirs?
b. There are two important basic requirements which should be fulfilled
to obtain high surface irrigation efficiency, Explain them.
(10 degree for each branch)
QII)
a. Demonstrate the Disadvantages of Basin irrigation as a method of
surface irrigation( 7 degree)
b. A sprinkler system irrigates turf grass on a clay loam soil on a 5%
slope in a 10 mph South wind. The sprinklers are 5/32”, single-
nozzle sprinklers with a 23° trajectory angle operating at 40 psi.
The sprinklers are arranged in a 30 ft x 50 ft rectangular spacing
with the laterals running East-West.(the following data help you to
solve the question, sprinkler 5/32” at 40 psi. their qs= 4.5 gpm, Dw
= 88 ft, for 8-12mph wind Sl max.=40% Dw , Sm max.=60% Dw.
for Turf, Recommended Max. Ar = 0.15-0.35 in/hr. Determine the
following requirements:
1.Is the sprinkler system design satisfactory for these conditions?
2.How many hours should the system operate in one zone? Assume
that dn=0.9 and Ea=0.80. ( 7 degree)
c. Mention (briefly) to the applications of Micro Irrigation. ( 6 degree)
QIII )
a. Illustrate the concealed problems at using the modern mechanized
system of Drip irrigation? (just five) ( 10 degree)
a. Write about the features of group II (YELLOW ) based on the
suitability of soil for irrigation( 10 degree)
QIV )
a. One aspect of SI is associated with the need to irrigate a larger area
in a short time during a drought spell. This conflicts with the
objective of minimizing costs. To overcome this problem there are
many strategies may be adopted, list there. ( 8 degree)
a. Calculate the number of dripper for orange tree planted with interval
(distance) of 5*5 in light soil (sandy soil) assume that the wetted area
ratio of (0.33)? And if you know that the maximum water
requirement is 125 L/day and the discharge of each emitter is 8 L/hr.
Determine the needed time for irrigation? ( 12 degree)
QV )
a. Illustrate with proper diagram the following:.
1- Components of impact sprinkler
2- Motion of water over border strip ( 6 degree)
a. A 1300 feet long lateral move system(Linear Pivot) has a minimum
travel time of 14 hrs at 100 % setting over its travel of 2640 feet and
is supplied of 600 gpm, what is the depth of application at a 17%
speed setting? ( 7 degree)
c. Illustrate the Advantages of Subsurface Drip Irrigation?( 7 degree)
Good Luck
Dr Akram A. Khalaf
Assist.Prof.
