River Upgrade Proposal

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HK01- CIVIL ENGINEERING PROGRAMME

FACULTY OF ENGINEERING

UNIVERSITI MALAYSIA SABAH

COURSE

KA30902 HYDRAULICS

TITLE

Babagon River Measurement and Upgrade

DATE OF SUBMISSION

23rd December 2015

PREPARED FOR

Mrs. Janice Lynn Ayog

PREPARED BY

MOHAMED FARIHAN MAIL

(BK13160569)


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Table of Contents

No. TITLES PAGE

1.0 Introduction 1-2

2.0 Methodology 3-5

3.0 Data and result 6-11

4.0 Discussion 12

5.0 Conclusion 12


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1.0. Introduction

“Water is life’s mater and matrix, mother and medium. There is no life without

water”, Albert Szent. Water is one of the most important aspect in life. Without it,

life itself would not exist. Babagon River has been providing fresh clean water to

villagers. Over the course of decades however, development at Kampung Babagon

has increase. Thanks to the government, villagers of Babagon are now using clean

treated water. Today the river is used as recreational purpose, a place where

family hang out and enjoy quality time during the weekend. The flow of the river

however is not efficient. To make matter worse, during monsoon season, the river

cannot drain all the surface water flowing from the village. Thus, the river need to

be upgraded. For the purpose of research, students were given a task to turn this

beautiful natural flowing river into a channel. The goal of this research is to

compute a modeling as well as designing a proper channeling using advance

computer software. To do so, site visit was conducted. During site visit, students

recorded four cross-sections of the river with an interval of 5m between each

cross-section. The speed of the river was also recorded.

1.1. River

According to Oxford dictionary, river is a large natural stream of water

flowing in a channel to the sea, a lake, or another river. Rivers are vital

providers of mineral water and nutrients to areas all around the earth. They

are critical components of the hydrological cycle, acting as water flow and

drainage channels for surface water. River offer environment, nutrition and

means of transport to countless organisms; they offer tracks for discovery,

business and recreation. Rivers are important to many of ecological issues

that concern community and they are analyzed by number of professionals

such as hydrologist, engineers, ecologist and geomorphologist. In basic

terms, the existence of a river relies upon three factors; the availability of

water surface, a channel in the ground and inclined surface. Active river

change over time, eroding and depositing sediments in predictable patterns

that are apparent in stream cross sections. Active eroding side of a river is

http://www.oxforddictionaries.com/definition/english/channel#channel__2http://www.oxforddictionaries.com/definition/english/channel#channel__2


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called scarp and the path of deepest channel is called thalweg, (Glenn

Merrick et. Al., 2008)

1.2. Channel

Any liquid flow in conduit with a free surface can be called as channel.

This free surface is subjected to atmospheric pressure. Position of the free

water surface makes flow condition in open channel complex. Not to

mention depth of flow, discharge and the slopes of both channel bottom

and free surface are also contributing to complexity.

There are several types of flow in channel. For example; steady and

unsteady flow, uniform flow, steady non-uniform flow and unsteady flow.

They are all govern by many factors such as; position of free water surface,

depth of flow, discharge, slope of channel bottom and slope of free surface

water.

Efficiency of any channel will affect the speed of water streaming

through it. The efficiency of a channel is govern by the channel’s surface

contact and surface roughness. The rougher the channel surface, the

higher the friction lowering the channel efficiency. Thus, smoother surface

of channel and less contact surface of water with the channel gives higher

channel efficiency.

1.3. Hec-Ras Software

The Hydrologic Engineering Centers River Analysis System (HEC-RAS)

is an advance computer software developed by U.S. Army Corps of

Engineers (USACE). With this advance software, users are able to execute

variety amount of flow. The software comes with 64-bit and 32-bit version

and it is compatible with Windows XP and above. The objective of this

report was to conduct channel modelling and channel designing for

Babagon River using advance HEC-RAS software.


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2.0. Methodology

2.1. EQUIPMENTS

Equipment used in conducting this research are as follows:

1.

Surveying Staff.2. Measuring Tape.

3. Current meter.

2.2. PROCEDURES TO OBTAIN CROSS SECTIONS DATA OF RIVER

In order to acquire the cross section information of the river; the

speed, depth and width of the river were measured. Four cross section

information were taken from upstream to downstream. The procedures are

as follows;

i) Measurements of the stream was taken using the current meter and

the river’s velocity was computed by taking an average of three value

of velocities.

ii) First cross-section area was selected and its cross section was

measured by stretching measuring tape across from the left of

riverbank to the right of river bank.

iii) The depth of the river were taken every 3m interval across the river for

every cross-section using a surveying staff.

iv) For next cross section, distance of five meters were measured from the

previous cross section and the depths were taken (Steps ii. and iii.).

v) Another 3 cross section of river were taken and step iv. was repeated.


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2.3. RIVER MODELLING

Data obtained from site visit was then computed and model of the

river using the HEC-RAS software was created. The procedures are as

follows;

i) The software was opened and new project file was created. This file

was then saved in new folder named “River Modelling” in desktop.

ii) The unit system was set to “System International (Metric system)”.

iii) In the main window, under “edit” menu bar, Geometric data was

keyed in and river reach was drawn and all four cross sections

obtained from the site visit were keyed in. The Manning ’ s coefficient

was set to be 0.03 for river bed that has a coarse-grained smooth

channel.

iv) Back main window, flow rates of a steady flow data was keyed in under

“edit” , “Steady Flow Data”

v) In the same steady flow data window, under boundary reach button

downstream and upstream was keyed in as “critical depth” .

vi) Back to the main window, steady flow simulator was performed by

clicking “Perform a steady flow simulation” . The button looked like a

person surfing on surface of water and positioned number 9 from themost left button.

vii) Finally, the result of the computation was obtained by clicking “River

cross section” and “ View 3D river cross section plot” .


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2.4. RIVER CHANNELLING DESIGN

Once the river modelling was computed, a design of a river

channelling is then computed using the HEC-RAS software. The

procedures are as follows;

i) The software was opened and new project file was created. This file was

then saved in new folder named “River Modelling” in desktop.

ii) The unit system was set to “System International (Metric system)”.

iii) In the main window, under “edit” menu bar, Geometric data was keyed in

and river reach was drawn and all four same cross sections (1.5m deep,

3m wide) were keyed in. The Manning’ s coefficient was set to be 0.03 for

river bed that has a coarse-grained smooth channel.

iv) Back main window, flow rates of a steady flow data was keyed in under

“edit” , “Steady Flow Data”

v) In the same steady flow data window, under boundary reach button

downstream and upstream was keyed in as “critical depth” .

vi) Back to the main window, steady flow simulator was performed by clicking

“Perform a steady flow simulation” . The button looked like a person surfing

on surface of water and positioned number 9 from the most left button.

vii) Finally, the result of the computation was obtained by clicking “River crosssection” and “ View 3D river cross section plot” .


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3.0. DATA AND RESULTS

3.1. RIVER CROSS SECTIONS DATA

Three velocities obtained from current meter = 0.9m/s, 1.2m/s, 1.4m/s

Velocity, V = (0.9 + .2 + .4)3

= 1.166 m/s ≈ 1m/s

Cross-sections

1 2 3 4

Width(m)

26.720 27.330 28.570 29.600

Depth at 3m intervals(m)

0.150 0.050 0.400 0.110

0.260 0.120 0.240 0.300

0.390 0.270 0.420 0.310

0.690 0.320 0.580 0.470

0.760 0.590 0.760 0.530

1.500 0.800 1.040 0.830

1.220 1.000 1.200 1.020

1.480 1.290 1.380 1.210

1.390 1.380 1.300 1.500

0.580 1.160 0.50 1.310

0.400 0.390

Cross-section Area, A(m2)

22.90 19.430 23.0 22.90

Flow Rate, Q=AV(m3/s)

22.90 19.430 23.090 22.90


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3.2. RIVER MODELLING

Figure 3.1. First Cross section of Natural River.

Figure 3.2. Cross section of Natural River 5m from first cross section.


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Figure 3.5. River profile from four cross section.

3.3. RIVER CHANNELLING DESIGN

Figure 3.6. First Cross section of Concrete Channel.


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Figure 3.7. Cross section of Concrete Channel 5m from first cross section.



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Figure 3.10. Concrete Channel profile from 4 cross section.


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4.0. DISCUSSION

During site visit, it was observed that the right bank of the river is going

through erosion while the left bank has a decreasing slope. It was also observed

that the river is deeper toward right side of the bank compared to the left side of

bank. The river bed was full of smooth and slippery stone. Precautions had to be

taken while taking measurement. The staff was carefully placed during recording

of depth so that the staff reach actual bed of river.

By using data of the river obtained from site visit, the modelling of the

Babagon River was computed using the advance HEC-RAS software to obtain its

profile. After profile of the river was obtained, channel design was conducted. A

channel was designed in such way that the new and improved channel would be

efficient and can sustain excess water surfacing during rainy season. The new and

improved Babagon channel is 1.5m deep and 30m wide. The width of this new

channel is 101.35% wider than the natural river while its area is 181.81 % larger

than the natural river which means it can transport surface water more efficiently.

By increasing the channel’s area, larger volume of water can be sustain by the

channel. This large area produce larger contact surface between water and the

channel, thus increasing friction. To overcome this, smooth concrete in which

lowers the Manning’s value is used to build the channel and decrease the friction.

By using rectangular shape as channel design, smaller top width can be achieved.

This cross section can benefit villagers of Kampung Babagon as its small top width

saves a lot of land usage.

5.0. CONCLUSION

To put it briefly, through the conduction of this assignment, data in which

defines the characteristics of the Babagon River was able to be determined. This

data was then put to use to compose the cross-sections of the river using the

HEC-RAS software thus providing an overview of the river’s shape. Similarly, this

data was also used to compute a channelling design for river upgrading purposes

based on the model constructed. In short, all objectives of this assignment was

accomplished.

River Upgrade Proposal

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