Poster prepared by Gizaw Desta, Menelik Getaneh and Amare Tsigie at the Nile Basin Development Challenge (NBDC) Science Workshop, Addis Ababa, Ethiopia, 9–10 July 2013

1. • The advance time of irrigation was
recorded at different furrow gradients
and discharge rates. Four furrow
gradients (0.5 %, 1 %, 2 %, and 2.5
%) were chosen at different sites. The
furrow discharges were selected out of
the recommended discharge sizes in the
feasibility study. Three discharges (0.3
l/s, 0.6 l/s and 0.8 l/s) were considered.
• Three adjacent furrows of length 90-
110 m are prepared. The central furrow
was used as an experimental furrow
while the two adjacent furrows
receiving equal discharge with the
center furrow were used as buffers.
• Two measuring RBC flumes were placed
at the beginning and end of each center
furrow. The application was terminated
when the stream flow through the
furrow outlet remains at steady flow.
• The travel time of water advancing
through the furrow (advance time) was
recorded at 10 m interval for the whole
furrow length using stopwatch. The
advance time was examined in two
irrigation cycles, first irrigation period
(February) and second irrigation period
(April).
• The advance time vary greatly among the
discharge rates when the furrow length
increases. For longer furrow lengths (90-110m)
the advance time was very slow and become
difficult to establish appropriate irrigation
operation rule and optimize the irrigation
management for the whole scheme. However,
in most of the test sites, the advance time was
more or less similar within 30-40 m furrow
lengths except at 0.3l/s.
• In the 1st irrigation, the respective advance
time to cover 30 and 40 m length was on
average 17-28 min and 28-56 min per furrow
at 0.6 l/s and 16-18 min and 25-30 min at 0.8
l/s discharge rate (Fig. 1).
• In the 2nd irrigation, the advance time to cover
30 and 40 m length became short, ranging
from 14-18 min and 24-32 min per furrow at
0.6 l/s and 14-18 min and 20-28 min per
furrow at 0.8 l/s discharge rate (Fig. 2).
• Therefore the discharge rate that requires
shorter application time is preferable as far as
its erosive capacity is low. It is thus feasible to
suggest 0.6-0.8 l/s application rate for slopes
up to 2-2.5 %.
• The advance time of water to cover 90-110
m furrow length at 0.5, 1.0, 2.0, and 2.5 %
field slopes was 213, 173, 150, and 369 min
at 1st irrigation, and 134, 182, 221, and 97
min at 2nd irrigation respectively (Fig. 3).
• The effect of slope results in great variation
of advance time at any point along the
furrow length.
• The inconsistency of advance time against
field slope was due to the irregularity of the
field and non-uniform surface roughness, for
instance, at 2.5% field slope, the advance
time is extremely slow at 1st irrigation.
• Comparing the 1st and 2nd irrigation cycles,
the advance time become shorter when the
field gets smoother as a result of further
tillage operation in the 2nd irrigation cycle.
• The existing operational furrow length at
Koga is extremely long which lead to very
low application efficiency
•With the given furrow length, irrigation
application time per furrow is long and
under such design it is difficult to establish
appropriate irrigation operation rules among
users for the whole scheme.
•The advance time by furrow length graphs
revealed that optimum furrow length at
different sites can only be possible at short
advance or application time.
•In order to maximize application efficiency
and minimize the losses, examining and
determining an optimum furrow length
before the operation of the whole scheme is
essential
•Irregular surfaces significantly affect the
furrow length, optimum discharge, the
application time and then application
efficiency. It implies that land leveling work
needs due attention so as to improve the
overall efficiency of the irrigation scheme.
Gizaw Desta Gessesse1 (desta.gizaw@yahoo.com), Menelik Getaneh1, and Amare Tsigie2
1Amhara Region Agricultural Research Institute (ARARI), 2Adet Agricultural Research Center
Introduction
Results
Furrow irrigation is the recommended
method for the distribution of water to the
fields at Koga irrigation scheme, found in
Western Gojam, Mecha wereda. However,
most surface irrigation systems have
inherent inefficiencies due to deep
percolation on the upper end and runoff at
the lower end of the field. A properly
managed surface system can attain
efficiencies of 60% or better. In a study
conducted by Kassa (2003) at Melka Werer,
with a furrow length of 200 m and different
inflow rates, the maximum attainable
application efficiency is 62 to 64%.
The strategies to improve furrow irrigation
efficiencies is by reducing runoff and deep
percolation losses. These losses depend on
furrow length, furrow gradient, discharge,
and cutoff time which need to be optimized
by irrigators to improve efficiency. This
paper presents the advance time of furrow
irrigation based on field data from Koga
under different discharge rates and furrow
gradients.
Methods
Effect of furrow gradient on advance time
NBDC Science Workshop, 9-10 July, 2013, Addis Ababa, Ethiopia
Examining Advance Time of Furrow Irrigation at Koga
Irrigation Scheme, Ethiopia
Conclusion and Recommendation
• The average advance time to cover
110 m furrow length at respective
discharge rates of 0.3, 0.6, and 0.8 l/s
range from,
• 195-435 min, 107-370 min, and 90-
300 min during 1st irrigation; and
• 70-380 min, 80-180 min, and 50-213
min during 2nd irrigation cycle.
Effect of discharge on advance time
Acknowledgment
We acknowledge Koga consultancy office for granting the research
0
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0 10 20 30 40 50 60 70 80 90 100110
Advancetime(min)
Furrow length (m)
Chona (0.5%)
0.3l/s
0.6l/s
0.8l/s
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400
450
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Advancetime(min)
Furrow length (m)
Laci 2 (1.0%)
0.3l/s
0.6l/s
0.8l/s
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200
250
300
350
400
450
0 10 20 30 40 50 60 70 80 90 100110
Advancetime(min)
Furrow length (m)
Laci 1(2.0%)
0.3l/s
0.6l/s
0.8l/s
0
50
100
150
200
250
300
350
400
450
0
10
20
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Advancetime(min)
Furrow length (m)
Kudmi (2.5%)
0.3l/s
0.6l/s
0.8l/s
Figure 1. Graph of advance time against furrow length,
1st irrigation
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350
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Advancetime(min)
Furrow length (m)
Chona (0.5%)
0.3l/s
0.6l/s
0.8l/s
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350
0
10
20
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Advancetime(min)
Furrow length (m)
Laci 2 (1%)
0.3l/s
0.6l/s
0.8l/s
0
50
100
150
200
250
300
350
0 20 40 60 80 100
Advancetime(min)
Furrow length (m)
Laci 1(2.0%)
0.3l/s
0.6l/s
0.8l/s
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100
150
200
250
300
350
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Advancetime(min)
Furrow length (m)
Kudmi (2.5%)
0.3l/s
0.6l/s
0.8l/s
Figure 2. Graph of advance time against furrow length,
2nd irrigation
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Advancetime(min)
Furrow length (m)
0.3 l/s
Chona Laci 2
Laci 1 Kudmi
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500
10 20 30 40 50 60 70 80 90 100 110
Advancetime(min)
Furrow length (m)
0.3 l/s
Chona Laci 2
Laci 1 Kudmi
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300
400
500
10 20 30 40 50 60 70 80 90 100 110
Advancetime(min)
Furrow length (m)
0.6 l/s
Chona Laci 2
laci 1 Kudmi
0
100
200
300
400
500
10 20 30 40 50 60 70 80 90 100 110
Advancetime(min)
Furrow length (m)
0.6 l/s
Chona Laci 2
laci 1 Kudmi
0
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200
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10 20 30 40 50 60 70 80 90 100 110
Advancetime(min)
Furrow length (m)
0.8 l/s
Chona Laci 2
Laci 1 Kudmi
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200
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500
10 20 30 40 50 60 70 80 90 100 110
Advancetime(min)
Furrow length (m)
0.8 l/s
Chona Laci 2
Laci 1 Kudmi
Figure 3. Relationship of advance time and furrow length
at different furrow gradients and discharge rates: 1st
irrigation (left) and 2nd irrigation (right). Chona = 0.5%;
Laci 2= 1%; Laci 1= 2%; and Kudmi=2.5%
References
Kassa and Fekadu (2003). Evaluation of the Performance of Surface
Irrigation Methods in Melka Werer, Middle Awash Valley. Arba Minch
University
This document is licensed for use under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License July 2013