Measuring discharge at a tradtitional small scale irrigation scheme; A personal report on the operation of the traditional irrigation scheme of Leza 1

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Personal Report on the Operation of the Traditional Irrigation Scheme Leza 1
February – July - November 2016
SMIS – SMALL SCALE & MICRO IRRIGATION SUPPORT PROJECT
Bahir Dar, Amhara Region, Ethiopia
MEASURING DISCHARGE AT A TRADITIONAL SMALL SCALE
IRRIGATION SCHEME

This report is a pilot study which
researches the irrigation scheme of Leza 1.
One of the pilot irrigation schemes of
SMIS project. The research focuses on
how data is being collected in Ethiopia
when measuring the water discharge, and
the possible different ways of measuring
discharge in irrigation schemes in
Ethiopia. This is done by researching
traditional methods, and by trying to gain
an impression of the efficiency of these
existing traditional measuring method in
comparison with other possible
measurement tools and methods.

Executed by: Joy Jamilla Pengel
Master student at Wageningen University:
International Land and Water
Management
&
Landscape Architecture
Special thanks to:
All the Colleagues of SMIS Amhara
Abbay Basin Authority
Bureau of Agriculture
District Agents (DA’s) of Leza 1
Farmers of the irrigation scheme Leza 1
Bureau of Water Resources in Bahir Dar
Engineering Department, University of
Bahir Dar
Koga (Durabilis) Farm
LIVES Project

Table of Contents
Introduction ............................................................................................................................................1
Situation Description ..........................................................................................................................1
SMIS Project........................................................................................................................................1
Missing Knowledge .................................................................................................................................2
My Role ...............................................................................................................................................2
Methodology Part 1................................................................................................................................3
Hypothesis...............................................................................................................................................4
Results.....................................................................................................................................................5
Measurements....................................................................................................................................5
Total data combined.......................................................................................................................5
Data per Measuring Tool ................................................................................................................5
Data per point of measuring...........................................................................................................6
Data set in Graphs...........................................................................................................................9
Controlled flume channel in the hydraulics lab, University Bahir Dar..........................................11
Correction Factor and its Influence ..................................................................................................11
Semi-Structured Interviews ..............................................................................................................11
Observation.......................................................................................................................................15
Methodology 2 (Extra measurement work July 2016). ........................................................................19
Fieldwork...........................................................................................................................................20
The method we used in the field ..................................................................................................20
Outcome Data Experiment 1 ........................................................................................................21
Possible Problems.........................................................................................................................21
Outcome Data Experiment 2 ........................................................................................................23
Conclusion.............................................................................................................................................25
Discussion and Reflection .................................................................................................................25
Recommendations............................................................................................................................26
References ............................................................................................................................................28
Annex 1 ....................................................................................................................................................i
1.1 Methodology..................................................................................................................................i
1.1.1 Methods used to calculate the water flow in the irrigation scheme......................................i
1.1.2 Interviews.............................................................................................................................. iv
1.1.3 Observations.......................................................................................................................... v
1.2 Data Sheet Current Meter ........................................................................................................... vi
1.3 Data sheet Floating Method ....................................................................................................... vii
Annex 2 ................................................................................................................................................ viii

Measurements taken on point 1: Main River.................................................................................. viii
Measurements taken on point 2: After first natural river................................................................ xii
Measurements taken on point 3: After both natural rivers in the main channel ............................ xv
Measurements taken on point 4: Secondary channel.....................................................................xvii
Measurements taken on point 5: More downstream of the main channel...................................xviii
Measurements taken in the hydraulic laboratory at the Bahir Dar University .................................xx
Annex 3 ...............................................................................................................................................xxiii
EC Meter River Flow Measurement: Dilution-Gauging Methods...................................................xxiii
Annex 4 ..............................................................................................................................................xxvii
Electric Conductivity (Dilution-Gauging) field Measurements taken near Bahir Dar Airport........xxvii
Electric Conductivity (Dilution-Gauging) field measurements taken at a stream called Infiranz on
the road from Bahir Dar to Zege...................................................................................................xxviii
Appendix 1 ..........................................................................................................................................xxix
List of contacts................................................................................................................................xxix

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Figure 1: Children herding a cow
Introduction
Situation Description
Ethiopia is a federal democratic republic. In every region public institutions are mandated to
manage the development, design, and construction of small scale irrigation schemes, and promote
the quality use of micro irrigation technologies at the household level. The effectiveness of this work
relies on well-resourced organizations that are led by skilled leaders and staffed with competent
individuals.
The irrigation sector is the responsibility of a number of public and private organizations at all
administrative levels. Development partners have responded to the GOE’s articulated priorities, and
are providing significant support to the sector through large-scale programs and projects.
The region this report will be focused on is the Amhara Region, with an in-depth analysis of the
scheme Leza 1 near Finote Selam. In this area there are usually 2 irrigation periods and 1 rain fed
agriculture period creating 3 potential harvest times in a year. Nevertheless, this is not always
feasible due to lack of rainfall or a late or early rain season. Also the amount of water available to
the scheme during the two irrigation periods may not be sufficient, which means that certain
farmers may not be able to irrigate their fields, or in the case that the water is being distributed
equally to each farmer the amount of water is not enough for any of them. From interviews
conducted during the study it seemed that when this phenomenon would occur the farmers usually
decide to only irrigate the perennial crops. There are also many other issues which may occur inside
an irrigation scheme, as there are numerous interventions to help and support the local farmers.
SMIS Project
The SMIS project, in support of the SSI Capacity Building Strategy and the Household Irrigation
Working Strategy, is designed to address specific aspects of organizational and technical capacity in
relation to the work of SSI and MI. Together with other initiatives, programs and projects such as
ATA, AGP-1, AGP-2 and LIVES, the SMIS project will support those public, and to a lesser extent,
private institutions responsible for SSI and MI to become high performing organizations with staff
that are ready to take on this challenge.

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Figure 2: Pepper plant affected by lice in one of the farms in Leza 1
Missing Knowledge
There has been quite some work done by SMIS, and its counterparts, to gather information on the
pilot schemes. Henceforth to get a better understanding of how they are being managed, irrigated,
the type of crops grown, etcetera. There is however still a limited understanding of the scheme
water flow during the dry season. Additionally there is no knowledge as to how different
measurements are being done.
My Role
There are three different aspects I will focus on and which hopefully will start some discussion and
additional research.
1. Trying to find out as much as possible on the Leza 1 irrigation scheme near Finote Selam.
 Calculating the amount of water that is available for the scheme.
 The type of crops grown.
 A rough calculation if the amount of water is enough for the crop production.
 Type of irrigation practised by the farmers.
 How the water is distributed.
 How decisions are being made if changes need to happen in the irrigation scheme.
 What are certain aspects that should be addressed and changed to ensure that
productivity of the farms increases?
 How is all this data being collected?
2. Using different measurement tools to measure the amount of water that flows into
schemes, to gain a better understanding which measurement tools would work best in
Ethiopia. Specifically to measure the traditional irrigation schemes. This is very important as
one needs to gather that data before designing a modern irrigation scheme.
 What is the traditional method being used to identify the amount of water that
flows into the irrigation scheme?
 What are other methods that could be used to measure the amount of water that
goes into the irrigation scheme?
 Which one is more accurate?
3. Through my own observations and discussions with experts, I will try to identify certain
aspects which in my own opinion need to be addressed to increase the production capacity
of the farmers.
 What are the main problems that I encountered?
 What are possible solutions towards these obstacles?

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Methodology Part 1
There are different types of methodology which are being used during this research to ensure that
the data collected is as accurate as possible, as there are different objectives. To find out what is the
most effective way to measure the discharge inside the irrigation channels of Ethiopia, different
measurement methods will be used. The methods that we are going to use are the traditional
floating method and a current meter. For the floating method we are using different materials to
find out which is the most suitable. These materials will be: an orange, water bottle, wine bottle, and
a leaf.
In addition to these research methods, interviews with the farmers (figure 3) and (traditional) water
board members will take place to gain an even clearer understanding of the irrigation scheme we
are looking into plus how the data collection usually takes place. To this our own observations will
be added as this will give even better and more accurate information as to what is actually going on
within the irrigation scheme; this may also guide the interviews. More details about the
methodology is given in annex 1.
Figure 3: Farmers being interviewed during field visit

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Hypothesis
There are different outcomes that could occur during my research. The aim to find out as much as
possible on the Leza 1 irrigation scheme near Finote Selam for instance does not have a clear picture
yet as to what will be the outcome. Especially as every place is different and therefore the structure
of the irrigation scheme is not so easily predicted except for its geographical aspects.
For the different measurement tools which are being used some hypothesis may be made. The
floating method is the most commonly used method in Ethiopia. However, I expect that the
methodology as to how they do the measurements is not very precise; the way that I have explained
the methodology (see Annex 1) is probably not the way that it is done during fieldwork. I also predict
that the current meter will be the most accurate method to calculate the amount of water in the
scheme as the corrections of the method are most likely more accurate.
As for my own observations during the fieldwork about what are problems related to irrigation
within the Leza 1 scheme I encounter, and solutions to certain problems: these are not aspects
which I can already predict as I have not been to the irrigation scheme yet.
Figure 4: The corn/maize harvest

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Results
Measurements
In this chapter you can find all the results gathered from the fieldwork. For the raw data and
calculations of each discharge measurement see Annex 2.
Total data combined
Table 1: Total Data Combined
Measurement point:
Mean Depth
(m)
Total Area
(m2
)
Mean Velocity
(m/s)
Total Discharge
(m3
/s)
Point 1.1 Current meter 0.06 0.18 0.11 0.060
Point 1 Float Orange 0.169/0.1/0.06 Aver. 0.392 Aver. 0.28 0.109
Point 1 Float Bottle 0.169/0.1/0.06 Aver. 0.392 Aver. 0.26 0.101
Point 2 Float Orange 0.412/0.40 Aver. 2.220 Aver. 0.06 0.126
Point 2 Float Wine 0.412/0.40 Aver. 2.220 Aver.0.05 0.115
Point 2 Float Bottle 0.412/0.40 Aver. 2.220 Aver. 0.05 0.122
Point 3 Current meter 0.16 0.392 0.04 0.028
Point 3 Float Wine 0.184/0.16 Aver. 0.151 Aver. 0.13 0.019
Point 3 Float Leaf 0.184/0.16 Aver. 0.151 Aver. 0.17 0.026
Data per Measuring Tool
Table 2: Data Current Meter
Measurement point:
Mean Depth
(m)
Total Area
(m2
)
Mean Velocity
(m/s)
Total Discharge
(m3
/s)
Table 3: Data Floating Method Orange
Measurement point:
Mean Depth
(m)
Total Area
(m2
)
Mean Velocity
(m/s)
Total Discharge
(m3
/s)

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Table 4: Data Floating Method Water Bottle
Measurement point:
Mean Depth
(m)
Total Area
(m2
)
Mean Velocity
(m/s)
Total Discharge
(m3
/s)
Point 3 Float Bottle 0.184/0.16 Avter. 0.151 Aver. 0.15 0.023
Table 5: Data Floating Method Wine Bottle and Leaf
Measurement point:
Mean Depth
(m)
Total Area
(m2
)
Mean Velocity
(m/s)
Total Discharge
(m3
/s)
Data per point of measuring
Table 6: Point 1 Measurements Combined
Measurement point:
Mean Depth
(m)
Total Area
(m2
)
Mean Velocity
(m/s)
Total Discharge
(m3
/s)
Figure 5: Photo of the site of point 1. Figure 6: Photo of how the current meter measurements where conducted.
Notes: There were some waves in the water which might have affected the data. We couldn’t
find a part of the river that was completely straight so that might also have influenced the data.
Also with the current meter 1.1 the propeller was a bit out of the water while conducting the
measurement; this may have caused some disturbance in results. However, when looking at the
outcomes of both current meter tests they are nearly the same so the disturbance will probably
have been minimal. It is interesting to see that the orange and bottle indicate a much lower
velocity than the current meter.

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Measurement point:
Mean Depth
(m)
Total Area
(m2
)
Mean Velocity
(m/s)
Total Discharge
(m3
/s)
Measurement point:
Mean Depth
(m)
Total Area
(m2
)
Mean Velocity
(m/s)
Total Discharge
(m3
/s)
Figure 7: Photo point 2 when using a wine bottle for the floating method. Figure 8: Photo boy measuring
the depth of the water.
Figure 9: Photo point 3 main channel downstream from the
two natural rivers.
Figure 10: Photo of measurement being taken through
current meter.
Notes: The boy moved a bit during the floating method this might have caused a bit of a
disturbance. Also there was not enough flow to use the current meter. It is interesting to see that
the wine bottle was faster than the orange and the water bottle as it was heavier and deeper in
the water.
Notes: A lot of vegetation growing inside the channel and other floating materials. Also as you
can see in the photos the water was carrying quite some sediment. With these measuring
method the wine bottle again measured a much faster velocity than the other methods used.

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Measurement point:
Mean Depth
(m)
Total Area
(m2
)
Mean Velocity
(m/s)
Total Discharge
(m3
/s)
Measurement point:
Mean Depth
(m)
Total Area
(m2
)
Mean Velocity
(m/s)
Total Discharge
(m3
/s)
Figure 11: Photo point 4. Figure 12: Photo when using the
current meter.
Figure 13: Photo of the vegetation
growth in the secondary channel.
Figure 15: Photo of the use of the current meter.Figure 14: Photo point 5.
Notes: A lot of vegetation inside the channel. Because the farmer was actually not supposed to
irrigate (there was no irrigation that day) we couldn’t test the floating method. The width of the
intake was 19.5 cm and the depth of the water passing through was on average 9.2 cm
Notes: There was hardly any wind. More sediment in the water. Also there was quite some
vegetation growth in the water. When we were doing the floating method we noticed that the
bottle seemed to first always go to the right side and then bend back to the left, never exactly
straight. The current meter measured quite a higher velocity than when using the floating method
of the orange and the water bottle.

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Data set in Graphs
Figure 16: Column graph showing all the data combined.

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Figure 17: Column graph of the final three points we measured.

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Controlled flume channel in the hydraulics lab, University Bahir Dar
Table 11: table showing measurements done in the controlled flume channel
Measurement Tool:
Mean Depth
(m)
Total Area
(m2
)
Mean Velocity
(m/s)
Total Discharge
(m3
/s)
Current meter 0.27 0.04 0.05 0.012
Float Orange 0.27 0.081 Aver. 0.22 0.018
Float Water Bottle 0.27 0.081 Aver. 0.21 0.017
Float Wine Bottle 0.27 0.081 Aver. 0.22 0.018
Flume measurements 0.27 0.081 - 0.025
Figure 18: Photos of the flume channel used in the hydraulics laboratory of the University of Bahir Dar.
Correction Factor and its Influence
Throughout this process there where different measurement systems used which of themselves had
their own correction factors. The correction factor used for the floating method was 0.65. This was
applied as this is the correction factor used in the traditional schemes in Ethiopia to ensure that the
distortion of the measurement through the flow distribution across the channel, as show in Annex
1.1.1, can become as minimal as possible. For the current meter a correction factor or 0.10 was
used.
Semi-Structured Interviews
To gain a better understanding of the whole irrigation scheme of Leza 1 several interviews were
conducted. With the farmers, DA of the scheme, and with the Woreda Agriculture Office. By talking
to all these people it was possible to gain a picture of the scheme, how the scheme is being
monitored and how it functions.
Notes: As it was inside there was no wind or other effects which could influence the data
collected. There were some problems in the beginning as the measuring tool for the flume was
not working. There was some dirt in the measuring tool which we first needed to clean up.
Another factor which might have influenced the outcome of the flume measurements is that the
formula which was used to calculate the discharge inside the flume was incorrect. Usually you
would just enter the level in an excel sheet which would then calculate the flow, or you would
have a table of which you can read the answer. This wasn’t available for this flume. We used the
formula given by the University of Bahir Dar.

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1. What type of irrigation is being used? (furrow, wild flooding, sprinkler, drip, etc.?)
All people interviewed gave the same answer to this question. The main irrigation method being
practiced in this scheme is furrow and wild flooding. There is also quite some water fetching
(especially for the fields or home gardens where they cultivate for personal use). However, whether
they actually do proper furrow irrigation remains questionable. Some of the fields that we visited
where we looked at the type of irrigation used
didn’t seem to be furrow irrigated areas even
though the farmers claimed that they were
using the furrow method for irrigation.
2. What is the amount of water that goes
into the irrigation scheme?
There was no knowledge about the amount of
water that goes into the irrigation scheme. The
farmers have a fixed amount of time to irrigate
their fields and then they have to close the
secondary channel again. Meaning that if the
water level is low within the main channel they
will get less water than when the channel is
high, regardless of what they need at the time. However, if there is a serious shortage of water they
may decide that the water is only used for the perennial crops (coffee, fruit trees, sugarcane) as
those will create a larger loss if they should die and need to be replanted.
a. How accurate are the fixed measurement structures?
There are no fixed measurement structures to measure how much water goes into the channels.
3. How much land is being irrigated now?
At this moment about 75 percent of the available land within the command area was being
cultivated through irrigation.
a. Is it possible to indicate this area on a map?
The areas where irrigation took place where mainly the start of the irrigation scheme and close to
the main channel. The potential irrigation areas further downstream are mainly used during the
rainy season1
. Hence not all the land was being cultivated. But even during the rainy season usually
less than 100 percent of the available land is cultivated. There are different reasons for this. One is
because of lack of incentive; for instance they don’t get extra income if they cultivate more as they
can’t get the crop to the large markets.
b. Is the amount of water that goes into the irrigation scheme still the same as
answered with the above question?
They do not know the amount that goes into the irrigation scheme so they cannot tell if there is a
difference in the amount of water during the different irrigation seasons.
1
The map that was drawn is not available anymore
Figure 19: Interviewing the farmers of Leza 1. Letting the
farmers draw where certain crops are grown and how much
land is being irrigated during the two irrigation seasons.

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4. What type of crops are grown and what is the approximate area of each crop in comparison
with the area of land being irrigated? (%)
The data that we gathered from this was so unclear that it was a hard to know if it was really
accurate. The way they knew how much they had was just through guessing what they harvested, or
by looking what the amount was last year and then increasing it. Also no one really had the data we
were looking for as the BoA of Finote Selam only had the sum of the whole area they are in charge of
and didn’t have the data per irrigation area, (which was the data that was needed). Eventually the
Kebele of Leza 1 gave us some data, but it was still unclear how this data was gathered. The main
crops grown in this area however where: sugarcane, onions, potato, maize, and coffee. It seems like
if you really need this information you have to calculate and collect the data yourself.
a. Is it possible to indicate the area for perennial and annual crops? (If they have both
types.)
They couldn’t give us the exact location of the perennial and annual crops. This could be gathered by
visiting all the sites but there was no time for it. It seemed that the perennial crops where mainly
situated close to the main channel.
b. Do they use crop rotation?
They use crop rotation, but only for the annual crops. With crop rotation they also have a year when
beans are planted which don’t give a large harvest, but this will improve the soil so the crops that
are grown afterwards get an increase in yield. This is something that the DA of the area tries to teach
the farmers.
c. How is the access for cash crops (perennial crops)?
The access to cash crops is quite okay. The only problem that the farmers face was that they first
need to gather the money to be able to afford the seeds. When they have perennial crops they get
priority with irrigation when the water level is too low to let all the farmers irrigate all their land.
Only the fields where the perennial crops are grown are then irrigated. However the connection to
the market is in some cases a bit hard which means that the farmers do not get as much profit as
could be possible if this was improved.
5. How is the water being distributed between al the farms?
The water is being distributed between the farmers by every village individually. The amount of
water that the village gets has to do with the number of residents inside the village. Each farmer gets
half an hour of irrigation water, regardless of the size of his field or the type of crops being grown.
The villages then decide the rotational scheme as to what time the fields are being irrigated. They
irrigate 24 hours a day, meaning that some farmers have to irrigate during the night. In some villages
female farmers have the privilege that they only get time slots to irrigate during the day, because of
safety reasons, but this is not the case in all the villages.
a. Is this with time slots or by amount of cubic meters?
The amount of irrigated water is for every farmer only half an hour, regardless of his or her field size,
crop or anything else.
6. How are these decisions being made about the irrigation scheme and the amount of water
each farmer gets?
a. Who makes the decision how much water each person gets?

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Figure 20: Some farmers of Leza 1 irrigation scheme who were interviewed
This has been decided by the water boards of the different villages a long time ago and hasn’t
changed. This might change when the new irrigation scheme is established.
b. and what happens if someone takes more or less? Who checks?
They get a large fine. The villagers themselves check each other and would bring people to the water
board if they take water when it is not their turn. However, we are told that apparently there are
hardly ever people who steal water. It is not clear if this is truly the case or if they were referring to
the situation now, when there is enough water.
c. What happens if the water availability is limited (e.g. If there is not enough water in
the reservoir?)
When this happens they decide to give priority to the perennial crops.
7. What type of help do you give/get from the farmers/water board/BoA office (DA)?
a. Do you feel like something is missing?
They give workshops on different topics, how to cultivate certain crops, how to protect plants
against diseases etc. The only aspect which could be improved is the support for identifying the
diseases and pesticides. Now there is only one expert for a whole region, which isn’t enough. He can
never reach all the farmers and check their fields.
8. What are in your opinion the restrictions/problems that should be solved to increase the
efficiency of the irrigation scheme?
According to the farmers, lining of the channels would ensure that there is less seepage. Also more
access to pesticide/herbicides and fertilizers would help, and an increase in the education of all the
farmers in the way of learning what is the most efficient way of irrigation. How for instance they can
calculate the Crop Water Requirement. These are the possible solutions that the farmers gave.

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Observation
When walking along the river and the main channel there were various activities that took place in
or around the water. At several occasions we observed that livestock used the water of the river and
channel to drink (figure 21-1). There did not really seem to be specific places which were allocated
for the animals to use for watering. Washing clothes and themselves is also an activity which people
do in the river upstream of the main channel. This could mean that the water used for irrigation has
some chemicals which may damage the crops. Another reason why this may be dangerous is
because the water is also being used as drinking water. Figure 21-4 shows how a boy was taking
some water from the river, downstream of where they were cleaning clothes.
11 12
1
3
14
Figure 21: The different activities occurring in this irrigation scheme. 1- Livestock Watering. 2- Water Fetching for farming
purposes. 3- Washing clothes and body. 4- Fetching water.

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Throughout the irrigation scheme one could find areas where seepage was occurring. This could be a
problem in periods when there is not enough water for all the irrigated land. The seepage is
happening due to channels not being constructed properly and water leaking through the sides
(figure 28 – 2) or due to the fact that there is hardly any current through the main channel (figure
22-1).
Another problem causing seepage is with the dams created before the main channel starts (figure
22-4). These two dams should direct the water towards the channel, but this is not the case. Also
some of the distribution structures are broken and let through a lot of water (figure 22 – 3). Every
time the farmers downstream have to irrigate they first need to close this with bags of sand.
However, the farmer installed these structures themselves and it does show initiative to try and
decrease seepage.
11
1
5
16
13 14
12
Figure 22: Water seepage problems and solutions. 1- Overflow, no clear bed of the main channel. 2- Seepage into secondary
channel. 3- Broken intake causing a lot of water seepage. 4- Natural rivers. 5- Plastic to control the amount of seepage. 6- A
properly maintained weir decreasing the amount of seepage.

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There are already measures being taken by individual farmers to decrease the amount of seepage
inside the main channel, such as using plastic sheets inside the channel through which the water
can’t infiltrate (figure 22- 5). Or well-maintained weirs that are not broken and will only be opened
when the farmer is irrigating his or her land.
When walking past the irrigation scheme there were also some other aspects which caught my
attention, which could have an effect on the water flow of the channel. There was quite some
floating material in the channel which could decrease the flow of the channel (figure 23 – 1). Also
there were only a few places where you could pass the main channel, and the bridges that were
constructed where mainly only for people. Animals have to go through the channel. This could cause
damage to the side slopes of the channels (figure 23 – 2). Not only animals pass through the channel,
but at some places you could see that vehicles had to pass through the channel causing damage
1
3
1
5
1
4
12
1
1
Figure 23: Extra observations. 1- Obstacles in the main channel. 2- Traditional bridges over the main channel. 3- The new
irrigation channel used to expand the irrigated area. 4- How data is being archived in the Woeda Bureau of Agriculture
connected to Leza 1 and 5- The main channel and the dam made to divert the water from the river to the main channel.

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Figure 24: Adding fertilizer to the crops.
(figure 23 – 3). It was also said that the main channel started at the first dam, but when we walked a
bit further you could find another place where another dam was created to ensure that the water
didn’t go back into the natural river (figure 23 – 5).
When we went to the Woreda Bureau of Agriculture connected to Leza 1 it was shocking to see how
the data was archived. Figure 23 – 4 shows how this was done. Hardly anything was saved digitally.
The problem with this is that it becomes quite hard to know if the data that they have is actually
accurate and quite often if you want to know something they could not find the information that
you were asking for. It could also help to ensure that if something happens, such as a fire, they do
not lose all their data. And at the same time it becomes easier to actually do something with the
data afterwards, for instance identify trends. However, for this to actually have any great
consequence the way that data gathering and validation, verification and management is being
conducted should become more transparent and accurate.

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Methodology 2 (Extra measurement work July 2016).
When my first assignment (January-February 2016) at SMIS Bahir Dar was finished, I still really
wanted to use the Dilution-Gauging method with an EC Meter to measure the river flow. The reason
why this was still on my “to do list” was because during the field work it became evident that certain
rivers/channels were really hard to use the Current Meter or the floating method. The reason for
this was for instance because there were a lot of rocks constantly distributing the water, and low
water discharge. Such a river could be seen in figure 25. It was not possible to calculate this
discharge due to the fact that both the current meter and the floating method could not be applied.
It would have been nice to be able to calculate this discharge measurement as the river flow
measurements right before and after the diversion dam in front of this river were already
conducted. However, there were no hand-held EC (Electric Current) meters which I could use to
measure the discharge during my first stay in Bahir Dar. When I came back in July we brought an
Electric Conductivity meter so I could do my experiment.
Figure 25: River after first dam at the Leza 1 Scheme.

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Fieldwork
When we went to collect the data we encountered several problems which resulted in the need to
change our methodology. One of these was that the electric conductivity measuring stick that we
used could not save the data automatically. This meant that the data was not as accurate as wished.
Also this meant that the sampling location was not precisely the centre of the channel (in the middle
and halfway down in the stream). But more of this will be discussed in the conclusion. Figure 26
shows the stream used for experiment 1.
The method we used in the field
The method we used was different than intended due to the lack of certain materials. The method
we used is:
1. Taking plastic cups and numbering them.
2. Measuring the salinity of the stream and writing this down.
3. Gathering 1.5 liter of stream water in a water bottle.
4. Adding 2 tea spoons of salt into the water bottle.
5. Mixing the salt and the water until it completely dissolved.
6. Measuring the salinity of the water bottle with salt.
7. Marking the start and the end of the trial river (at least 20 meters long).
8. At the same time of adding the salted water in the water bottle to the stream take the first
cup of water from the end position of the stream (cup number 1).
9. Every 5 seconds take a cup of water from the stream (going from cup number 1, 2, 3, etc.).
10. When all the water is taken measure the salinity in each cup and write down the results.
NOTE!: after each measurement properly clean the measuring tool with the stream water to
neutralize it.
11. Measure the depth at different intervals of the stream length, plus the width of the channel
at different places.
The methodology I used can be found in Annex 3. It is based on the Gooseff Hydroecology Science &
Engineering Lab at Colorado State University.
Figure 26: The stream used for experiment 1

Page | 21
Outcome Data Experiment 1
In the graph below (graph 1), you can see that there is no clear line showing the change in the
salinity which is found within the river flow (Annex 4). This is not how the graph should have looked.
Graph 2 shows how the graph is supposed to look like to ensure that the data collected was correct.
With this graph it becomes very hard, or not possible, to calculate a true discharge. This tells me that
something went wrong with this experiment.
Possible Problems
There are different aspects which could have caused the data to not be as expected. The first reason
that I will mention is that we did not use enough salt for this particular stream. This seems to be the
most logical answer to what went wrong. Looking back at the experiment one can calculate that we
added 40 times less salt than the prescribed amount! This is definitely not enough and would
account for the seeming lack of extra salinity in the stream. Therefore, because there was not a lot
of salt added to the water it might be that the difference of salinity measured by the EC meter of the
water of the stream did not change that much as it spreads throughout the whole stream. It needs
extremes to be able to measure the peak flow of the salinized water and hence calculate the stream
discharge.
The second reason could be that we didn’t measure long enough and that therefore our data didn’t
go back to zero yet. This is clearly visible in graph 1, where you can see that the outcome does not go
back to the base line. Also if you look at the results in the table shown in annex 3 you see that the
last input of data was suddenly again relatively more saline than the rest. However, I do not believe
that this was the case. As to ensure that this would not be a problem again it would be smart to first
do a quick floating test to see how fast the leaf goes from the intake towards the measuring location
Graph 2: Data output of experiment 1. The amount of salt inside the river at a certain time.
Graph 1: How the graph is supposed to look like.

Page | 22
so that you have a rough estimation as to how long you at least have to conduct your
measurements.
A third reason why the data wasn’t as accurate could have to do with communication. It seemed
that the team didn’t understand me in the beginning when I tried to explain to them when and how
they should take the cups of water from the river. This made the data in the first three cups a bit
inaccurate. Another problem with the sampling of the water for the measurements was that we did
not take the water exactly from the middle of the stream, and only from the top part of the stream.
Even though the measurements should be made from the middle of the stream, halfway into the
stream. This could have caused problems with the outcome of the data.
The final reason why the data may not be as accurate as hoped for is because the EC measurement
tool was not accurate enough, and it could not log the results automatically at a given time interval.
It might be that the conductivity measurement tool that we have used in this text experiment is
actually not suitable for this type of measurements. In the experiment done in Iceland (Annex 3) an
Onset HOBO U24-001 Conductivity Logger was used, this might be a better tool to use than the one
that we have used (EC/TDS hydrotester model COM-80).

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Outcome Data Experiment 2
Figure 27: The infiranz river.
To try to solve the problem with the data collected the first time using the EC meter as measuring
device, the same experiment was repeated at the natural stream called Infiranz the way to Zege
(figure 27). However, this time we used significantly more salt than the previous time. 1 kg of salt
was mixed with 12 liter of stream water. Another aspect which was done differently was to first test
how fast the river flow was. This was done using the floating method to see how fast it took to travel
the distance of 10 meters which had been set out. This took about one minute. Therefore the
measuring started after one minute. For the rest we kept the same procedure of first measuring the
natural conductivity of the water, which was 94ppm. Then dissolving all the salt in the 12 liter of
stream water, and adding the whole content and rinsing the material afterwards to ensure that all
the salt went into the stream.
Graph 3: Data output of experiment 2. The amount of salt inside the river at a certain time.
As you can see from graph 3 there does now seem to be a very clear peak in the measured ppm of
the river flow. This gives us the feeling that the data collected is more accurate. Also the discharge
measured which is 705.362 L sec-1
seems to be more accurate than with experiment 1. This gives the
impression that the reason why experiment 1 did not work was because of the little amount of salt
added to the water.
monitor point: 10 m
injection point: 0 m
ec probe: EC_04
slug in: 13:55:00 HH:MM:SS
1st arrival: 13:55:00 HH:MM:SS
background: 94.00 mS cm-1
peak time: 13:55:12 HH:MM:SS
peak cond: 149.00 mS cm-1
peak conc: 74.50 mg L-1
end monitoring: 14:07:58 HH:MM:SS
modal v: 0.833 m sec-1
slug mass: 992.1 g
0th moment: 1406.497 mg L-1
sec
discharge: 705.362 L sec-1
t adv 00:00:12 HH:MM:SS

Page | 24
One aspect which makes the data gathered a bit strange are the two sudden peaks occurring when
the ppm measurement was going down (see graph 3). I do not really know why this occurred and
what the actual reason for this was, though a lack of full mixing could be responsible. This might be
checked and confirmed if more of these experiments using this method are carried out. Repeating
the measurement will help to give a clearer picture as to the end results. Especially if unexpected
disturbances occur like the cows who came to drink from the stream (figure 27).
An aspect which might help to improve this data collection method even more would be if the time
laps between the measurements taken of the ppm inside the river flow was done closer together to
ensure that the outcome of especially the peak period would have been more precise. Also it would
have helped if the measurements would have started a bit before the one minute after the salty
water was added to the stream as the ppm measurement now taken started at 97 ppm (annex 3).
The neutral measurement of the ppm was 94 ppm. This means that already some of the salted water
might have passed through before the one minute laps times. Thirdly, repeating the experiment at
least three times will ensure that the data collected is as accurate as possible and will decrease the
chance of uncertainty. Finally, it might be useful to measure the ppm inside the cups during the
sampling already, to ensure that the data seems to be accurate or not.
Figure 28: How the samples were collected. Figure 29: Measuring the ppm inside each sample.
Figure 30: Writing down the results

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Conclusion
Looking at the outcome of all the data it shows once again that the information gathered is not
always what you expect. It is really hard to find a correlation as to which method is the most
accurate as the difference between the methods is constantly changing. One aspect which seemed
to be constant the whole time is that the Current Meter has usually the lowest m³/s. except at point
3. There are various possible reasons for this change, but one reason for this might be because the
channel was not that deep at that point so when using the floating method it was a bit harder for the
materials to float an not be disturbed by the vegetation in the channel.
In addition, if you look at the numbers it seems as if there is no seepage of water from point 3 until
point 5. This is quite interesting as it would suggest that something has changed from these two
measurement areas. However, you need to look at the numbers and the discharge difference is only
0.0002 increase of discharge from measuring point 3 to measuring point 5, so it might also just be a
measurement error. To ensure that this is really not the case it is important to repeat the
measurements and check whether there is a similar difference again.
Correspondingly the controlled method inside the university flume had some problems as explained
in the chapter about results. This means that this method should ideally be repeated to ensure that
the data collected is more accurate and that we can actually say something about the outcome of
the measurement. This is something for future research.
From the interviews and the observations in the field it became clear that it is very important to
work together with the farmers within the scheme, to check how they are using the irrigation
channels now, and hence what functions the channel should need in the future. This is a strong
aspect of the SMIS project. Also it showed that not only lining the channels and modernizing the
irrigation scheme is needed. It also indicates that farmers within Leza 1 irrigation scheme need more
education on how to irrigate their land properly (CWR), how to identify pests and diseases, what to
do when they occur, how to prevent them, etc. With this knowledge the yield gap would decrease
creating a larger and better quality harvest and an increase in income for the farmers.
As for the EC meter method for calculating the water discharge, there are still follow-up steps which
need to be taken to ensure that the data collected using this method is more reliable and
understandable. The use of this method of conducting this research would be very interesting and
useful, especially for all the streams which are not suitable for the float or current meter method.
Discussion and Reflection
There are certain limitations towards my research and eventually the results. One of these is that it
would have been better if I could have visited the irrigation scheme beforehand to decide where I
would do the discharge measurements. This would have ensured that I would have had more time to
do the actual measurements in the field. This was also the case when conducting the EC meter
method as finding the right channel/river/stream close to Bahir Dar for this type of experiment was
harder than was expected beforehand.
This brings me to the second aspect. Due to the lack of time in the field the total amount of field
research was limited; it would have been better if there was more time for the measurements. For
future research on this topic I would really recommend to increase the amount of time available for
field work.
Thirdly, the results from the measurements done in the flume at the university do not seem to be
correct. It is still unclear what went wrong, but I would like to have repeated the research as this

Page | 26
dataset is quite important to identify the accuracy of the different measurement methods we used.
When I returned on my second visit I was told that the flume was not accurate and that using the
floating method would be more accurate than the flume. This directly gives a idea as to the
assumptions of university staff on how accurate the flume is.
Finally, using the EC meter to calculate the discharge was something new for me and something that
I had not tried before or had seen done. This ensured that I virtually needed to start from scratch. As
this was the case, the first time doing the experiment was very clumsy and not as accurate as I had
hoped for. In addition the measurements were done during the rainy season. Which meant that
getting to the rivers/streams was quite hard and also finding the right type of river/stream seemed
to be a challenge.
Recommendations
There are a lot of aspects which I would recommend for additional research. As I hardly had enough
time to do my research properly I would recommend that there is further and more thorough
research being done on discharge measurement tools in order to get an idea which one is the most
accurate an precise to use for the irrigation schemes in Ethiopia.
Furthermore it would be really interesting to measure the discharge of the Leza River throughout
the entire dry season. For instance to do measurements each month at the same locations. This
would give a better idea of the possibilities of the irrigation scheme, the water availability. The
farmers now said in the beginning that the river nearly always has the same amount of discharge.
Yet, at the same time they do tell that when the water from the river is low they only irrigate the
perennial crops. This then seems to indicate that there is a difference in the amount of water
available from the river.
The above could be facilitated by installing a simple V-notch weir in the main channel, at which it
would be comparatively simple to measure the discharge. This would also allow comparison with the
various other methods in a more straightforward manner.
It would have also been really interesting to create a map of how the traditional irrigation scheme is
now. Especially because the farmers say that there are different places where spring water comes in
and joins the main channel ensuring that the water discharge increases again. Now it is unknown
where these springs exactly are and if they are actually within the Leza 1 irrigation scheme or only at
the end of the irrigation scheme. This would be interesting especially as it seemed as if there was an
increase in water towards the end of the main channel. This could be because of inaccuracy of the
measurements. But it is also possible that there is inflow of groundwater. If this is the case then the
irrigation channel should not be lined at those areas.
Fourthly I would recommend to study how and even if knowledge, of which there is a lot of in
Ethiopia, reaches the famers. Not only in the context as to how the governmental institutes are
operating, but also how they choose to give which trainings. There is already a quite vast
explanation as to the dissemination of information within Ethiopia. However, it is not clear in what
cases this process is going well and where there may be room for improvements. It would also be
interesting to find out the attitude of the farmers towards those DA’s working for the Bureau of
Agriculture.
As for the Dilution-Gauging method with an EC Meter there are also various studies which should be
done to get a better understanding of this relatively new and rather unknown way of calculating
discharge. These possible research topics are:

Page | 27
• Try the same experiment with even more salt.
• Increase the frequency of sampling, especially around the peak of the salinity, to capture
this peak more accurately
• Measure the water salinity for a longer period of time.
• Take the measurements of the salinity in the centre of the channel.
• If possible try to get an EC meter which saves the data automatically at given time intervals.
• Try the same experiment with two EC meters and keeping them inside the water and every
time the seconds have passed click on hold take that EC meter out of the water and write
down the salinity of the water. At the same time put the other EC meter into the water so
that when the next measurement needs to be done the measurement is stable.
• Try the methodology on different irrigation channels, streams, etc.
These are the different studies which I believe should really be done to ensure that there is a more
thorough understanding of this method and to see whether this method is applicable in Ethiopia,
and if yes, under which circumstances.
Figure 31: The main channel of Leza 1

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References
Environmental field techniques: Stream Discharge measurement I: Float and Velocity-Area Methods
<http://www.colorado.edu/geography/courses/geog_2043_f01/lab 01_2.html> date of :
11/07/2016
New, D., (2005) Measuring Head and Flow. <http://www.homepower.com/articles/microhydro-
power/design-installation/intro-hydropower-part-2> 01/02/2016
Michaud, J. P. & Wierenga. M., (2005) ESTIMATING DISCHARGE AND STREAM FLOWS: A Guide for
Sand and Gravel Operators. Washington State Development of Ecology.
Wlostowski, A. N., Smull, E. M., Gooseff, M.N., (2012). Measuring Discharge With Conservative
Trachers.<https://goosefflab.wordpress.com/2012/07/26/measuring-discharge-with-conservative-
tracers/> the Gooseff Hydroecology Science & Engineering Lab at Colorado State University

Page | i
Annex 1
1.1 Methodology
1.1.1 Methods used to calculate the water flow in the irrigation scheme
Where to conduct the measurements in an irrigation scheme
When conducting the measurements it is important to choose
the right spot. There are different guidelines for choosing the
right spot, but for this research measurements will be taken, if
possible, at each change of flow within the irrigation scheme.
Thus, where the irrigation scheme starts, the main channel,
the secondary channel, etc.
To get the best results it would be recommended to do the
measurements at three points at each of these changes (see
the sketch in figure 32). That way you can find out how
accurate your measurements are. For instance, the sum of the
water discharge at point 2 and 3 should equal the water
discharge at point 1.
Floating method:
To use the floating method it is very important that you
choose a good and representative part of the irrigation
scheme to do the measurements. Conditions that you should keep in mind when selecting the
gauging site are:
o The reach should be straight.
o Channel width should be relatively uniform along the reach.
o Channel cross section shape should be relatively uniform along the reach.
o Flow direction should be parallel with the channel sides along the reach, with no eddies or
stones or stagnant (‘dead’) water.
o The channel should be clear and unobstructed by trees, aquatic growth or other obstacles.
o Sites subject to backwater effects by downstream obstacles should be avoided.
o All of these conditions mentioned should be valid for at least a length of 5 meters from the
different locations of the irrigation channel that you want to measure.
After this has been done you first start with measuring the geometry of the reach (see figure 33):
1. Measure the length of the reach in meters between the upstream and the downstream cross
sections using a surveyors measuring tape. The length of the reach should be a minimum of
3 meters and may be up to 10-15 meters longer if the channel conditions are constantly the
same.
2. Measure the width of the irrigation channel by recording the width of the water surface with
a measuring tape at different verticals alongside the reach of your experimental area.
3. At each of those points, measure the depth at regular verticals across the channel using a
steel tape and calculating an average depth. Use a board that can span across the whole
channel and mark it at 0.2 m verticals. Lay the board across the stream, and measure the
stream depth at each 0.2 m interval. To compute the average depth, add all of your
measurements together and divide by the number of measurements you made.
4. The cross section area is measured multiplying the width by the mean depth.
5. Enter the geometry data into the excel file.
Figure 32: Where to do the measurements

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Figure 33: Floating method
When all the geometry measurements have been completed the calculations for the velocity of the
water will be executed. This will be done through the following steps:
1. Use a weighted float that can be clearly seen—an orange or grapefruit works well.
2. Place it well upstream of your measurement area, and use a stopwatch to time how long it
takes to travel the length of your measurement section. Start the stopwatch when the float
crosses the upstream cross section. This can be signalled by spanning a string across the
water at the upstream cross section to ensure that the data will become more accurate (see
figure 33). Do the same for the downstream cross section.
3. Repeat this several times. Minimum of 3, but if the data collected varies a lot keep on
repeating the measurement until there is not too much variation between the different
values. The stream speed probably varies across its width, so measure the time for different
locations spaced at regular verticals across the channel
4. Calculate the average water velocity by dividing the length of the reach by the average travel
time. Note that this figure is an average velocity for the water at the surface at the stream.
Velocity decreases with depth to the stream bed. Therefore an average stream velocity
should be computed by multiplying the average surface velocity by a velocity coefficient. The
velocity coefficient may be assumed to take the value 0.65. Note that the velocity coefficient
may be computed by measuring actual average stream velocity with a current meter and
dividing this by the surface velocity measured with the float.
5. Enter the velocity data into the field form in the excel file.
http://www.homepower.com/sites/default/files/articles/ajax/docs/08_HP104_pg42_New-4.jpg
Extracted on: 01/02/2016

Page | iii
The traditional method that is mainly being used in the field in Ethiopia is the floating method. For
this method one usually finds something that can
float, for instance a piece of bamboo or a leaf (these
are most commonly used). However, these methods
are not the most accurate as it will ensure that you
only measure the top part of the whole channel. And
because these objects float directly on the surface
they will be influenced more by other elements such
as the wind (figure 34).
To identify if there really is a difference in calculating
the water discharge into the channel using other
materials than the traditionally used ones, the
floating method will be conducted and different
floating materials will be used to find out if the
outcome varies between the different floating
materials.
The materials that will be used are:
o An orange
o A plastic water bottle
o A wine bottle
o A leaf
Not all of these methods will be tested at each place
as not all the methods may be possible to do due to
the conditions of the channels.
Current meter:
Wading method:
The wading method involves having the hydrographer stand in the water
holding a wading rod with the current meter attached to the rod. The
wading rod is graduated so that the water depth can be measured. The rod
has a metal foot pad which sits on the channel bed. The current meter can
be placed at any height on the wading rod and is readily adjusted to another
height by the hydrographer while standing in the water (see figure 35).
1. First the width of the channel is being calculated perpendicular to
the flow direction from one edge of the water to the other one.
2. Depending on the width, different numbers of verticals will be
measured. Table 12 shows the different number of verticals in
correspondence with the width of the channel.
Table 12: How to decide the number of verticals
Channel width (meters) 0-0.5 0.5-1 1-3 3-5 5-10 >10
Number of verticals 3-4 4-5 5-8 8-10 10-20 >20
3. At each interval point the depth is being measured and written down (see annex 1a).
4. Depending on the depth of the channel the calculations for how high the propeller needs to
be situated will need to be calculated. If the depth is lower than 0.5 meter then you simply
http://www.colorado.edu/geography/courses/geog_2043_f01/lab01_2.html
Figure 34: Different velocity in a channel
Figure 35: How to put the
current meter inside the water

Page | iv
multiply the measured depth with 0.4. If it is deeper than 0.5 meter then you should
multiply the measured depth with 0.2 and 0.8. The velocity of the water then needs to be
calculated at two different heights at the same interval.
5. When these calculation are done and written down, the hydrographer standing in the water
will use measuring tape strapped from one side of
the channel to the other side of the channel as
reference point as to where he needs to place the
rod with the current meter attached to it.
6. BEFORE placing the wading rod in the water, adjust
the height of the propeller so that it is the exact
height as calculated.
7. The hydrographer stands 5-10 cm downstream from
the measuring tape that is strapped across the
channel and approximately 50 cm to one side of the
wading rod.
8. During the measurement, the rod needs to be held
in a vertical position and the current meter must be
parallel with the flow direction.
9. When everything is in proper position the hydrographer can star the measuring and the
results will be written down on the sheet.
10. Step 5 up to 9 will be repeated for each vertical measurement in the channel.
11. All data will be inserted in the excel sheet to calculate the exact discharge.
Controlled research of the different methods.
When the measurements have been done in the field the exact measurement methods will be done
again in a controlled environment. This will be at the University of Bahir Dar, in the hydraulics
laboratory. As there will hardly be any other forces which may influence the outcome this test will
give us a clearer understanding about the accuracy of each measuring method. Hence, helping us
answer the research question which method is the most accurate.
1.1.2 Interviews
The interviews will be semi structured interviews. The questions that I would like to raise are:
1. What type of irrigation is being used? (Furrow, wild flooding, sprinkler, drip, etc?)
2. What is the amount of water that goes into the irrigation scheme?
a. How accurate are the fixed measurement structures, if any?
3. How much land is being irrigated now?
a. Is it possible to indicate this area on a map?
b. Is the amount of water that goes into the irrigation scheme still the same as
answered with the above question?
4. What type of crops are being grown and what is the approximate area of each crop in
comparison with the area of land being irrigated? (in %, rough estimate)
a. Is it possible to indicate the area for perennial and annual crops? (If they have both
types.)
b. Do the farmers use crop rotation?
c. How is the market access for cash crops?
5. How is the water being distributed between al the farms?
a. Is this with time slots or by volume (cubic meters)?
http://geographyfieldwork.com/Qmes.sch2.gif
Figure 36: Sketch of midsection: how to
collect the data for the current meter

Page | v
6. How are decisions being made about the irrigation scheme and the amount of water each
farmer gets?
a. Who makes the decision how much water each person gets
b. and what happens if someone takes more or less? Who checks?
c. What happens if the water availability is limited (e.g. If there is not enough water in
the reservoir?)
7. What type of help do you give/get from the farmers/water board/BoA office (DA)?
a. Do you feel like something is missing?
8. What are in your opinion the restrictions/problems that should be solved to increase the
efficiency of the irrigation scheme?
9. Is there anything else that you feel that I have left out and that you would like to tell me?
This is already quite elaborate. However, I do not need precise answers for each of these questions.
During the interview I will start by asking them to explain how the irrigation scheme works and from
what they then explain to me I decide which follow up questions to ask. This way the interview will
gather the most interesting information as it will ensure that you get a clear understanding what the
person you are interviewing really thinks and knows about certain topics. From that topic you then
go to the next topic. Through this method you eventually go through all the different questions as
stated in the above, and maybe some more questions will be answered.
1.1.3 Observations
Observations will be done throughout the whole process. As I do not know a lot about Ethiopia and
how things are done here, it is important to stay alert and constantly look around and make notes
and photos of aspects that catch my interest.
This observation study will also be done when doing the floating and current meter method for
finding the amount of water passing through the channel. I will try to gain an understanding what
the normal procedure is for gathering this data and ask why the measurements are done in a certain
way. Through this I hope to be able to trigger the experts to become more critical in their own
research.
Also just walking through the irrigation scheme will be very useful to gather information as to the
state of the scheme and what kind of problems it might face. Seeing how a farmer irrigates its land
will also be very useful as it will directly give a first-hand experience to see how well they know how
to irrigate their land. For example: if a farmer says he uses furrow irrigation, to check if it is really
furrow irrigation or if it is more like wild flooding.

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1.2 Data Sheet Current Meter
Monitoring Location: Measuring time: 60 sec
Date/time: GPS data: N. S. El.
Staff gauge (m)
Vertical/
sub
section
Distance on
tape (vertical)
(m)
Depth at
vertical
(m)
Observational
depth (0.4D)
(m)
No. of rev’s in
measured
period.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Notes:

Page | vii
1.3 Data sheet Floating Method
Date: Time start-end:
Start from left bank,
divide stream into 5-
10 equal sections.
DEPTH at Cross Section Profile
(upstream cross section)
(middle stream cross section)
(downstream cross section)
Total with (m): Total with (m): Total with (m):
0 cm (left bank)
(Edge right bank)
Distance from LB
(cm)
Water depth
(cm)
Distance from LB
(cm)
Water depth
(cm)
Distance from LB
(cm)
Water depth
(cm)
Float Measurements Velocity measurement 1
(upstream cross section)
Velocity measurement 1 (middle
stream cross section)
Velocity measurement 1
(downstream cross section)
Length of reach (m)
Section (as per
above)
Distance from LB
(m)
Time (s) Distance from LB
(m)
Time (s) Distance from LB
(m)
Time (s)
Notes:

Page | viii
Annex 2
Measurements taken on point 1: Main River
Date Amharic: 24/5/2008 Time at start: 10:48 Staff Gauge at start: none
Date Gregorian: 01/02/2016 Time at end: 03:36 Staff Gauge at end: none
Station: Leza ant (+/- 150 meters Upstream of the tradtional intace (orange)) Name of site manager: kabele DA (name?)
Start from left bank, divide stream into 5-10
equal sections
Total Width (metres): 3.4 Total Width (metres): 4 Total Width (metres): 3.6
Distance from LB (cm) Water Depth (cm) Distance from LB (cm) Water Depth (cm) Distance from LB (cm) Water Depth (cm)
0 cm (Left bank) 0 0 0 0 0 0
50 25 50 10 50 4
100 26.5 100 14.5 100 7
150 30 150 14.5 150 9
200 27 200 13 200 9
250 18 250 12 250 9
300 8.5 300 9 300 6
350 0 350 5 350 3
(Edge right bank)
Mean depth (m): 0.169 0.10 0.06
Area of Cross section profile (m2): 0.57 0.39 0.21
FLOAT MEASUREMENTS
Length of reach (metres): 8.2 8.2 8.2
Section (as per above) Distance from LB (m) Time (seconds) Distance from LB (m) Time (seconds) Distance from LB (m) Time (seconds)
0 cm (Left bank) 0 0 0 0
50 50 50
100 100 100
150 22.59 150 22.59 150 22.59
200 20.52 200 20.52 200 20.52
250 20.6 250 20.6 250 20.6
300 300 300
350 350 350
(Edge right bank)
Average no of seconds over the reach: 16 21 21
Average velocity for measurement 1 (m/s): 0.51 0.39 0.39
CALCULATION OF DISCHARGE (m3/s) OBSERVATIONS (weather, flow conditions, difficulties experienced during measurement)
Average cross section area: 0.392
Average measured velocity (m/s): 0.43
Velocity coefficient: 0.65
Average channel velocity (m/s): 0.28
Discharge (Flow) (m3/s): 0.109
DEPTH at Cross Section Profile 1 (upstream cross
section)
DEPTH at Cross Section Profile 2 (middle cross
section)
DEPTH at Cross Section Profile 3 (downstream
cross section)
VELOCITY MEASUREMENT 1 VELOCITY MEASUREMENT 2 VELOCITY MEASUREMENT 3

Page | ix
Date Gregorian: 01/02/2016 Time at end: 03:36 Staff Gauge at end: none
Station: Leza ant (+/- 150 meters Upstream of the tradtional intace (water bottle)) Name of site manager: kabele DA (name?)
equal sections
Total Width (metres): 3.4 Total Width (metres): 4 Total Width (metres): 3.6
0 cm (Left bank) 0 0 0 0 0 0
50 25 50 10 50 4
100 26.5 100 14.5 100 7
150 30 150 14.5 150 9
200 27 200 13 200 9
250 18 250 12 250 9
300 8.5 300 9 300 6
350 0 350 5 350 3
(Edge right bank)
Mean depth (m): 0.169 0.10 0.06
FLOAT MEASUREMENTS
Length of reach (metres): 8.2 8.2 8.2
0 cm (Left bank) 0 0 0 0
50 50 50
100 100 100
150 25.45 150 25.45 150 25.45
200 21.75 200 21.75 200 21.75
250 21.54 250 21.54 250 21.54
300 300 300
350 350 350
(Edge right bank)
section)
section)
cross section)

Page | x
Monitoring location: Leza ant 1.1 (+/- 150 meters Upstream ofGPS data
Date: 2/01/2016 Northing:10.424793
Time: 11 am (5 ethiopian time) Easting:37.372881
Staff gauge (m): None Elevation: 1882 m above sea level
Measuring Period (seconds): 60
Vertical Dist on Width of Depth Area Observational No. of No. of Velocity Mean Vert. Mean Sub. Discharge Observations, including
/ Sub- Tape Sub-section at Vertical Subsection Depth (0.4D etc) Revs in Revs / sec at point Velocity Sect. Velocity sediment samples
Section m m m m2 m Meas. Period n m/s m/s m/s m3/s
1 0 0.50 0.00 0.01 0 0 0.00 0.00 0.00 propellor partially above the water
0.00 0.00
2 0.5 0.50 0.04 0.03 0.025 50 0.83 0.43 0.22
0.00 0.00
3 1 0.50 0.07 0.04 0.028 52 0.87 0.45 0.22
0 0.00 0.00
4 1.5 0.50 0.09 0.05 0.036 62 1.03 0.53 0.27
0 0.00 0.00
5 2 0.50 0.09 0.05 0.036 72 1.20 0.62 0.31 the depth measured changed
0 0.00 0.00 because of the waves in the water.
6 2.5 0.50 0.09 0.04 0.036 86 1.43 0.74 0.37 propellor partially above the water
0 0.00 0.00
7 3 0.50 0.06 0.02 0.024 62 1.03 0.53 0.27 propellor partially above the water
0 0.00 0.00
8 3.5 -3.50 0.03 -0.05 0.025 0 0.00 0.00 0.00
0 0.00 0.00
9 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
10 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
11 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
12 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
13 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
14 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
15 0.00 0.00 0 0.00 0.00 0.00
0.00 0.00
16 0.00 0.00 0.00
0.00 0.00
TOTAL MEAN TOTAL MEAN TOTAL Carry over to another sheet if
WIDTH DEPTH AREA VELOCITYDISCHARGEnecessary. Repeat Vertical No. 16
m m m2 m/s m3/s at top of next sheet.
TOTAL 0.00 0.06 0.18 0.11 0.060
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.32 0.012
0.13 0.003
0.00 0.000
0.25 0.010
0.29 0.013
0.34 0.015
0.11 0.001
0.22 0.006

Page | xi
Monitoring location: Leza ant 1.2 (+/- 150 mGPS data
Date: 2/01/2016 Northing:10.424793
Time: 11 am (5 ethiopian time) Easting:37.372881
Measuring Period (secon 60
Vertical Dist on Width of Depth Area bservation No. of No. of VelocityMean VertMean SubDischargeObservations, including
/ Sub- Tape Sub-sectioat VerticaSubsectiopth (0.4D eRevs inRevs / secat point Velocity Sect. Velocity sediment samples
Section m m m m2 m eas. Perio n m/s m/s m/s m3/s
1 0 0.50 0.00 0.03 0 0 0.00 0.00 0.00
0.00 0.00
2 0.5 0.50 0.10 0.06 0.04 26 0.43 0.23 0.12 More stagnant water (visually)
0.00 0.00 then measurement 1
3 1 0.50 0.15 0.07 0.058 32 0.53 0.28 0.14 More stagnant water (visually)
0 0.00 0.00 then measurement 1
4 1.5 0.50 0.15 0.07 0.058 36 0.60 0.31 0.16
0 0.00 0.00
5 2 0.50 0.13 0.06 0.052 39 0.65 0.34 0.17 More stagnant water (visually)
0 0.00 0.00 then measurement 1
6 2.5 0.50 0.12 0.05 0.048 42 0.70 0.36 0.18
0 0.00 0.00
7 3 0.50 0.09 0.04 0.036 41 0.68 0.35 0.18
0 0.00 0.00
8 3.5 0.50 0.05 0.01 0.025 30 0.50 0.26 0.13 Propellor a lot out of the water
0 0.00 0.00
9 4 -4.00 0.00 0.00 0 1 0.02 0.02 0.01
0 0.00 0.00
10 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
11 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
12 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
13 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
14 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
15 0.00 0.00 0 0.00 0.00 0.00
0.00 0.00
16 0.00 0.00 0.00
0.00 0.00
WIDTHDEPTH AREA VELOCITSCHARGnecessary. Repeat Vertical No. 16
TOTAL 0.00 0.09 0.39 0.07 0.058
0.06 0.001
0.13 0.008
0.15 0.011
0.16 0.011
0.18 0.011
0.18 0.009
0.15 0.005
0.07 0.001
0.01 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000

Page | xii
Measurements taken on point 2: After first natural river
Date Gregorian: 02/01/2016 Time at end: Staff Gauge at end: none
Station: Leza Ant (Measurement 2, after frist natural river dam (with Orange)) Name of site manager: none
equal sections
Total Width (metres): 5.71 Total Width (metres): 5.2 Total Width (metres):
0 cm (Left bank) 0 0 0
50 19 50 34
100 27 100 50
150 58 150 51
200 63 200 52
250 67 250 54
300 65 300 52
350 67 350 49
400 61 400 46
450 52 450 37
500 36 500 16
550 21 520 0
571 0
(Edge right bank)
Mean depth (m): 0.412 0.40 #DIV/0!
Area of Cross section profile (m2): 2.35 2.08 #DIV/0!
FLOAT MEASUREMENTS
Length of reach (metres): 10 10 10
0 cm (Left bank) 0 0 0 0 0 0
50 50 50
100 100 100
150 150 150
200 200 200
250 152.02 250 152.02 250 152.02
300 143.85 300 143.85 300 143.85
350 162.62 350 162.62 350 162.62
400 400 400
450 450 450
500 500 500
550 550 550
(Edge right bank) 571 571 571
Average measured velocity (m/s): 0.09 The boy who helped with the measurements was in the water and the moved once. This might have caused a little bit of disturbance.
section)
section)
cross section)

Page | xiii
equal sections
50 19 50 34
100 27 100 50
150 58 150 51
200 63 200 52
250 67 250 54
300 65 300 52
350 67 350 49
400 61 400 46
450 52 450 37
500 36 500 16
550 21 520 0
571 0
(Edge right bank)
Mean depth (m): 0.412 0.40 #DIV/0!
FLOAT MEASUREMENTS
0 cm (Left bank) 0 0 0 0 0 0
50 50 50
100 100 100
150 150 150
200 200 200
250 166.03 250 166.03 250 166.03
300 178.75 300 178.75 300 178.75
350 158.32 350 158.32 350 158.32
400 400 400
450 450 450
500 500 500
550 550 550
Average measured velocity (m/s): 0.08 The boy who helped with the measurements was in the water and the moved once. This might have caused a little bit of disturbance.
section)
section)
cross section)

Page | xiv
Station: Leza Ant (Measurement 2, after frist natural river dam (with Water Bottle) Name of site manager: none
equal sections
50 19 50 34
100 27 100 50
150 58 150 51
200 63 200 52
250 67 250 54
300 65 300 52
350 67 350 49
400 61 400 46
450 52 450 37
500 36 500 16
550 21 520 0
571 0
(Edge right bank)
Mean depth (m): 0.412 0.40 #DIV/0!
FLOAT MEASUREMENTS
0 cm (Left bank) 0 0 0 0 0 0
50 50 50
100 100 100
150 150 150
200 200 200
250 145.98 250 145.98 250 145.98
300 181.16 300 181.16 300 181.16
350 147.07 350 147.07 350 147.07
400 400 400
450 450 450
500 500 500
550 550 550
Average cross section area: 2.220 The boy who helped with the measurements was in the water and the moved once. This might have caused a little bit of disturbance.
section)
section)
cross section)

Page | xv
Measurements taken on point 3: After both natural rivers in the main channel
Station: Leza Ant (Measurement 3 near the second natural river dam (with Orange)) Name of site manager: none
equal sections
0 cm (Left bank) 0 0 0 0 0 0
20 19 20 18
40 29 40 24
60 30 60 26
80 28 80 27
100 24 100 20
120 17 120 0
140 0
(Edge right bank)
Mean depth (m): 0.184 0.16 0.00
FLOAT MEASUREMENTS
20 21 20 21 20 21
40 21.81 40 21.81 40 21.81
60 20.5 60 20.5 60 20.5
80 20.01 80 20.01 80 20.01
100 21.29 100 21.29 100 21.29
120 22.02 120 22.02 120 22.02
140
(Edge right bank)
Average measured velocity (m/s): 0.24 Some grass
Velocity coefficient: 0.65 a lot of other leafs and other materials floating in the water.
section)
section)
cross section)
Station: Leza Ant (Measurement 3 near the second natural river dam(With Wine Bottle Name of site manager: none
equal sections
0 cm (Left bank) 0 0 0 0 0 0
20 19 20 18
40 29 40 24
60 30 60 26
80 28 80 27
100 24 100 20
120 17 120 0
140 0
(Edge right bank)
Mean depth (m): 0.184 0.16 0.00
FLOAT MEASUREMENTS
20 26.4 20 28.4 20 28.4
40 25.86 40 25.86 40 25.86
60 24.25 60 24.25 60 24.25
80 24.45 80 24.45 80 24.45
100 25.56 100 25.56 100 25.56
120 27.96 120 27.96 120 27.96
140
(Edge right bank)
Average cross section area: 0.151 Some grass
Average measured velocity (m/s): 0.19 a lot of other leafs and other materials floating in the water.
section)
section)
cross section)

Page | xvi
Station: Leza Ant (measurment 3, near the second natural river dam (with Water Bottl Name of site manager: none
equal sections
0 cm (Left bank) 0 0 0 0 0 0
20 19 20 18
40 29 40 24
60 30 60 26
80 28 80 27
100 24 100 20
120 17 120 0
140 0
(Edge right bank)
Mean depth (m): 0.184 0.16 0.00
FLOAT MEASUREMENTS
20 25.32 20 25.32 20 25.32
40 19.63 40 19.63 40 19.63
60 18.35 60 18.35 60 18.35
80 18.16 80 18.16 80 18.16
100 19.68 100 19.68 100 19.68
120 24.8 120 24.8 120 24.8
140
(Edge right bank)
Average measured velocity (m/s): 0.24 Some grass
Velocity coefficient: 0.65 a lot of other leafs and other materials floating in the water.
section)
section)
cross section)
Station: Leza Ant (Measurment 3, near the second natural river dam (with Leaf)) Name of site manager: none
equal sections
0 cm (Left bank) 0 0 0 0 0 0
20 19 20 18
40 29 40 24
60 30 60 26
80 28 80 27
100 24 100 20
120 17 120 0
140 0
(Edge right bank)
Mean depth (m): a 0.184 0.16 0.00
FLOAT MEASUREMENTS
20 20 20
40 19.01 40 19.01 40 19.01
60 18.9 60 18.9 60 18.9
80 17.76 80 17.76 80 17.76
100 18.84 100 18.84 100 18.84
120 18.85 120 18.85 120 18.85
140
(Edge right bank)
Average cross section area: 0.151 Some grass
Average measured velocity (m/s): 0.27 a lot of other leafs and other materials floating in the water.
section)
section)
cross section)

Page | xvii
Measurements taken on point 4: Secondary channel
Monitoring location: Leza ant 3. (point 3 main channel after sGPS data
Date: 3/01/2016 Northing:10.720966
Time: 10 am Easting:37.362718
1 0 0.20 0.00 0.02 0 0 0.00 0.00 0.00
0.00 0.00
2 0.2 0.20 0.18 0.04 0.072 21 0.35 0.19 0.09 Grass on the side effected the
0 0.00 0.00 outcome
3 0.4 0.20 0.24 0.05 0.096 33 0.55 0.29 0.14
0 0.00 0.00
4 0.6 0.20 0.26 0.05 0.104 33 0.55 0.29 0.14
0 0.00 0.00
5 0.8 0.20 0.27 0.05 0.108 33 0.55 0.29 0.14
0 0.00 0.00
6 1 0.20 0.20 0.02 0.08 28 0.47 0.25 0.12
0 0.00 0.00
7 1.2 -1.20 0.00 0.00 0 1 0.02 0.02 0.01
0 0.00 0.00
8 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
9 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
10 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
11 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
12 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
13 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
14 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
15 0.00 0.00 0 0.00 0.00 0.00
0.00 0.00
16 0.00 0.00 0.00
0.00 0.00
TOTAL 0.00 0.16 0.23 0.04 0.028
NOTES: There where quite some leaves and other floating materials in the water
Observer Date
0.05 0.001
0.12 0.005
0.14 0.007
0.14 0.008
0.13 0.006
0.07 0.001
0.01 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000

Page | xviii
Measurements taken on point 5: More downstream of the main channel
Station: Leza Ant (Measurment 5, down the main channel 1 km from point4 (Orange)) Name of site manager: none
equal sections
Total Width (metres): 1.3 Total Width (metres): 1.6 Total Width (metres): 1.5
0 cm (Left bank) 0 0 0 0 0 0
20 9 20 6 20 11
40 11 40 9 40 11
60 13 60 10 60 12
80 13 80 11 80 10
100 13 100 13 100 9
120 8 120 12 120 8
130 0 140 9 140 5
(Edge right bank) 160 0 150 0
Mean depth (m): 0.084 0.08 0.07
FLOAT MEASUREMENTS
20 30.84 20 30.84 20 30.84
40 30.51 40 30.51 40 30.51
60 29.52 60 29.52 60 29.52
80 26.89 80 26.89 80 26.89
100 26.91 100 26.91 100 26.91
120 30 120 30 120 30
140 30.71 140 30.71 140 30.71
Average cross section area: 0.114 the bottle first goes to the left and then to the right the first 4 times this might be because of the turn before the place of measurement
Average measured velocity (m/s): 0.34 a lot of grass
Velocity coefficient: 0.65 hardnly any wind
section)
section)
cross section)
Station: Leza Ant (Measurment 5, down the main channel 1 km from point4 (water bottle))
equal sections
Total Width (metres): 1.3 Total Width (metres): 1.6 Total Width (metres): 1.5
0 cm (Left bank) 0 0 0 0 0 0
20 9 20 6 20 11
40 11 40 9 40 11
60 13 60 10 60 12
80 13 80 11 80 10
100 13 100 13 100 9
120 8 120 12 120 8
130 0 140 9 140 5
(Edge right bank) 160 0 150 0
Mean depth (m): 0.084 0.08 0.07
FLOAT MEASUREMENTS
20 27.19 20 27.19 20 27.19
40 26.63 40 26.63 40 26.63
60 26.71 60 26.71 60 26.71
80 25.97 80 25.97 80 25.97
100 25.93 100 25.93 100 25.93
120 26.86 120 26.86 120 26.86
140 29.99 140 29.99 140 29.99
Average measured velocity (m/s): 0.37 the bottle first goes to the left and then to the right the first 4 times this might be because of the turn before the place of measurement
Velocity coefficient: 0.65 a lot of grass
Average channel velocity (m/s): 0.24 hardnly any wind
section)
section)
cross section)

Page | xix
Monitoring location: Leza Ant 5 (first secondary channel fromGPS data
Date: 03/01/2016 Northing: 10.721026
Time: 12.00 Easting: 37.362543
1 0 0.16 0.00 0.01 0 0 0.00 0.00 0.00
0.00 0.00
2 0.16 0.16 0.08 0.01 0.032 23 0.38 0.21 0.10
0 0.00 0.00
3 0.32 0.16 0.11 0.02 0.042 18 0.30 0.16 0.08
0 0.00 0.00
4 0.48 0.16 0.12 0.02 0.048 23 0.38 0.21 0.10
0 0.00 0.00
5 0.64 0.16 0.11 0.01 0.044 26 0.43 0.23 0.12
0 0.00 0.00
6 0.8 -0.80 0.00 0.00 0 1 0.02 0.02 0.01
0 0.00 0.00
7 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
8 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
9 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
10 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
11 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
12 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
13 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
14 0.00 0.00 0 0.00 0.00 0.00
0 0.00 0.00
15 0.00 0.00 0 0.00 0.00 0.00
0.00 0.00
16 0.00 0.00 0.00
0.00 0.00
TOTAL 0.00 0.07 0.07 0.03 0.006
NOTES: a lot of grass growht, the size of the intake was 19.5 cm. The depth of the water flowing into it varied and was: 8, 10, 11, 9, 8 cm deep.
Observer Date
So the average depth of the water passing through was: 9.2 cm
0.05 0.000
0.09 0.001
0.09 0.002
0.11 0.002
0.06 0.001
0.01 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000
0.00 0.000

Measuring discharge at a tradtitional small scale irrigation scheme; A personal report on the operation of the traditional irrigation scheme of Leza 1

Measuring discharge at a tradtitional small scale irrigation scheme; A personal report on the operation of the traditional irrigation scheme of Leza 1

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