UNESCO-NIGERIA TECHNICAL & VOCATIONAL

EDUCATION REVITALISATION PROJECT-PHASE II

YEAR I- SE MESTER I.

NATIONAL DIPLOMA IN

CIVIL ENGINEERING TECHNOLOGY

INTRODUCTORY HYDROLOGY COURSE CODE: CEC102

TABLE OF CONTENT

WEEK ONE: Measurement of discharge

WEEK TWO: Continuation of measurement of discharge. Results

were obtained

WEEK THREE; Metrological instruments were introduced to the

students in the laboratory

WEEK FOUR: Infiltration measurement in the laboratory

WEEK FIVE: Observation of the flow of run-off in open drain and

assessment of run-off relation with drain capacity

WEEK SIX: Field observation of clouds and recording of beginning

and ending of rainfall

WEEK SEVEN; Visit to old Kaduna airport to see weather forecast

equipments.

WEEK EIGHT; Visit to Kaduna International Airport to see new

weather forecast equipment

WEEK NINE: Measurement of pressure using U-tube manometer in

Chemical engineering laboratory

WEEK TEN: Visit to weather station at the National Water

Resources Institute, Mando Kaduna

WEEK ELEVEN: Another visit to old Kaduna Airport for

immediate measurement of rainfall using rain gauge.

WEEK TWELVE: Visit to a site of construction of rectangular open

drainage

WEEK THIRTEEN: Visit to another site for the construction of

trapezoidal shape open drain

WEEK FOURTEEN: Visit to Kaduna Water Board Headquarters to

see how hydrological data are kept and use.

WEEK FIETEEN: Visit to a bridge along Kaduna- Zaria road for

stage measurement

PRACTICALS

WEEK ONE

TITLE: MEAUREMENT OF DISCHARGE

AIM: To introduce the students to the apparatus and how to measure the discharge

in a channel and pipe.

APPARATUS

1. Stop watch

2. Shovel

3. Pegs

4. Measuring tape

5. Ruler

6. Venturimeter

THEORY

In order to measure the rate of flow (discharge) in the laboratory, a venturimeter is

used. But there are other methods that are used in the field, in order to measure the

discharge. Among the methods are the following:

1. Area-velocity method

2. Slope-area method 4

3. Salt-concentration (or trace) method

4. Moving boat method

5. Indirect method

6. Electromagnetic method and ultra-sonic method

The theory of pipe flow is that the flow that enters the pipe must be the same with

what will leave the pipe provided there is no leakage. Using the discharge equation

for pipe flow, we have:

Q = A x V

Where Q is the discharge

A is the area

V is the velocity

In considering the continuous flow nature of water flow in a pipe, continuity

equation is applied as follows:

Q = A1V1 = A2V2

PROCEDURE

1. Initially the channel section where the experiment will be conducted was

identified.

2. The length of the channel was measured and divided into segments of various

lengths. 5

3. The length was measured to be 12 m and it was divided into four segments of 3

m each.

4. All the things that will bring obstacles were removed to prevent obstructions.

5. The width, height of channel as well as depth was measured.

6. The class was divide into various groups.

7. Two floating bodies were dropped at a known point and the time is noted. By

the time the floats reach the end point, another time is also recorded.

Due to time factor, the students stopped here for this week.

6

Wind

Evaporation from

Falling Rain

Solar

Radiation Falling Rain Falling Rain

Transpiration

Run-Off

Evaporation

Sea Lake Storage Percolation

Infiltration

Stream Flow Ground H2O

Fig 1.1 Hydrological Cycle Diagram

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Clouds

1.4 Hydrology as applied in engineering

To the practicing engineer concerned with the planning and building of hydraulic

structures, hydrology is an indispensable tool. For example, a community or city is

rapidly increasing in population, and there is need to expand the existing water supply.

The engineer first looks for sources of supply, having perhaps found a clear uninhabited

mountain catchment area, he must make an estimate of its capability of supplying water.

How much rain will fall on it? How long will dry periods be and what amount of storage

will be necessary to even out the flow? Would a surface storage scheme be better than

abstraction of the groundwater flow from wells nearer the city?

The questions do not stop there. If a dam is to be built, what capacity must the spillway

have? What diameter should the supply pipelines be? Would afforestation of the

catchment area be beneficial to the scheme or not?

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PRACTICALS

WEEK TWO

The practical continued from where we stopped last week

RESULTS

Position Time

t1(sec)

Time t2

(sec)

Depth of

flow

(mm)

Distance

(m)

Width of

channel

(m)

Depth of

channel

Example of a case of a rectangular section channel that has the following at position

1:

Length = 0.019 m

Breadth = 0.73 m

Average velocity = 0.2143 + 0.2143 = 0.2143 m / sec

2

Area of the channel = Length x Breadth

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= 0.019 x 0.73 = 0.013 m2

Discharge = A x V

Q = A x V

Q = 0.0139 x 0.1243 = 2.979 x 10-3 m3 / sec.

In the case of flow in pipe, after demonstration in a transparent pipe model, the

students were given the value of pipe diameter and velocity and are asked to

calculate the discharge as follows:

The diameter of the pipe = 0.15 m

The velocity of flow = 1.5 m / sec

Therefore, the discharge is given as: Q = A x V

Q = x d2 x V 4

= (0.15)2 x 1.5 = 0.027 m3/ sec 4

Therefore Q = 0.027 m3/ sec

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PRACTICAL

WEEK THREE

The students were taken to a laboratory in the department of

Agricultural engineering, where metrological instruments are kept.

TITLE: INTRODUCTION TO METREOLOGICAL INSTRUMENTS

AIM OF THE PRACTICAL

1. To know more about metrological station.

2. To know how to measure rainfall using rain gauge.

3. To know how to measure evaporation using evaporation dish.

4. To know how to measure temperature with wet bulb and dry bulb thermometer.

5. To know how to measure humidity using hygrometer

6. To know how to measure wind using wind vane

7. To know how to measure wind speed using anemometer

8. To understand how to measure precipitation using rain-o-meter.

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APPARATUS

1. A Stevenson screen

2. Wet bulb thermometer

3. Dry bulb thermometer

4. Rain-o-meter

5. Evaporation pan

6. Rain gauge

7. Wind vane

8. Wind anemometer

9. Measuring cylinder

Students were ask to draw rain gauge, thermometer and evaporation pan

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PRACTICAL

WEEK FOUR

The students were taken to the laboratory to measure infiltration

TITLE: Measurement of infiltration

AIM: To see the instrument and measure infiltration

APPARATUS

1. Double Ring infiltrometer

2. Flat bar

3. Bucket

4. Stop watch

5. Hammer

6. Scriber

7. Beaker

PROCEDURE

The site for locating the internal and external ring of the infiltrometer is first

identified. Then the rings are sunk into the soil. Bucket was used to fetch water and

it was poured into the inner and outer ring at the same time. The stop watch is used

to record the time. After one hour, the reading is taken and after each five minutes

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interval reading is taken. Steel ruler is used to measure and takes reading in order to

know the depth of infiltration. The exercise continues for two hours, the time we

observed the water is saturated.

TABLE

Elapse time

(cm)

Distance of

water

surface

from

reference

point

(before

filling)

Distance of

water

surface

from

reference

point (after

filling)

Depth (cm) Average

infiltration

Accumulated

infiltration

The students were given assignment to calculate the infiltration rate at each depth in

cm / hr.

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PRACTICAL

WEEK FIVE

Students were divided into three groups. Each group was given a site where an open

drain is located. They were asked to go and observe the flow of run-off into the

drain.

AIM: The aim is to observe run-off flow and assess its relationship with the

capacity of the drain.

The students were given assignment to measure the depth and width of each drain

before the rainfall. Then during the flow of the run-off water, they should record the

height of the water. They should find out whether the capacity of the drain is

sufficient for the flowing run-off water in the area?

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PRACTICAL

WEEK SIX

The students were asked to observe the cloud outside the department as the clouds

are formed prior to rainfall. They were asked to record the time the rain started to

fall and the time it stopped

AIM: By the time the students observe the clouds on the sky by themselves, they

will appreciate the difference of clouds.

. At the end, they were given an assignment to draw and explain the type of clouds

they have observed and the duration of the rainfall.

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PRACTICAL

WEEK SEVEN

This week the students visit the Kaduna old airport in order to see the instruments they

are using in their weather forecast. They were conducted round the airport where they

were shown different kinds of instruments.

AIM: The aim is for the students to see different types of instruments

After the visit, the students were asked to write a report on all the instruments they have

seen and what they are used for.

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PRACTICAL

WEEK EIGHT

This week the visit took us to Kaduna International airport. The students were taken

round to see the equipments used for weather forecast at the airport.

AIM: The aim of the visit is to compare between the equipments that are in the old

airport and the ones in the new airport.

After the visit, the students were told to draw and explained the types of equipments they

saw. Also, they should compare what they saw at the old airport with what they met at

the new airport.

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PRACTICAL

WEEK NINE

The students were taken to chemical engineering laboratory where they were shown

a U-tube manometer and they used it in the laboratory to measure pressure

AIM: To see the measurement instruments that are used in the laboratory.

At the end of the exercise, the students were given the values of density of water

and mercury, and they were asked to calculate the density at position A, i.e. PA

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PRACTICAL

WEEK TEN

This week the students visited the weather station of the National Water

Resources Institute, Mando Kaduna.

AIM: The aim is to see variety of equipments

The students got the opportunity to see a fully equipped Stevenson

screen. Therefore after the visit, they were asked to fully describe what

a typical Stevenson screen contained

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PRACTICAL

WEEK ELEVEN

This week the students went back to Kaduna old airport as it is just about to rain.

AIM: The aim of the visit is to enable the students to observe and record rainfall

using a rain gauge

The students were able to observe the rainfall recording and after the rainfall, they

opened the rain gauge and observe the level of water recorded in it.

The students were asked to write a report on the whole exercise..

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PRACTICAL

WEEK TWELVE

The visit this week took us to a site in Kduna township where construction of open drain

is in progress.

AIM: The aim of the visit is to show the students how an open drain is constructed. This

will give the students the idea how run-off water is collected and discharged into a bigger

drain for final discharge to Kaduna River.

At the site the students visited, it is a rectangular open drain that is constructed.

Therefore, the students were asked to measure the depth, length and breadth of the drain.

They were given assignment to draw the section of the drain and given a velocity they

were asked to calculate the amount of water (discharge) the drain is expected to carry.

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PRACTICAL

WEEK THIRTEEN

This week the visit continues with site visit. The students visited another site

where an open drain is being constructed.

AIM: The aim of the visit is to see another site where an open drain of trapezoidal

cross-section is under construction.

The students were again given a velocity of flow and were asked to take the

dimensions of the trapezoidal drain in order to get its area. They were expected to

submit a report on the visit and to calculate the capacity of the drain.

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PRACTICAL

WEEK FOURTEEN

The practical for this week took the students to Kaduna State Water

Board Headquarters.

AIM; The aim of the visit is to show the students the importance of hydrological

data.

At the data office of water board, the students were shown data that was

stored for many years. In order to show them example, they were given

the average values of rainfall duration and depth for the month of May

(2007) for some areas within Kaduna metropolis..

After the visit, the students were told to calculate the intensity of

rainfall for Kaduna using the data they got from water board.

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PRACTICAL

WEEK FIFTEEN

This week the students visited a bridge over a river along Kaduna-Zaria road.

AIM: The aim of the visit is to show the students how stage readings are taken in a river.

Even though, the time of the visit was not during raining season but the students

were shown the staff that is normally fixed to one of the pillars of the bridge which

is used to measure the level of water in the river.

After the visit, the students were asked to draw the staff and record the level of

water that was found at the time of the visit.

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CoverTable of ContentsWEEK ONEWEEK TWOWEEK THREEWEEK FOURWEEK FIVEWEEK SIXWEEK SEVENWEEK EIGHTWEEK NINEWEEK TENWEEK ELEVENWEEK TWELVEWEEK THIRTEENWEEK FOURTEENWEEK FIFTEENReturn to Table