sediment transport in kulim river, malaysiaredac.eng.usm.my/html/publish/2005_09.pdf · 2019. 10....

XXXI IAHR CONGRESS 1397

SEDIMENT TRANSPORT IN KULIM RIVER, MALAYSIA

CHANG CHUN KIAT 1, AMINUDDIN AB GHANI

2,

NOR AZAZI ZAKARIA 3 and ROZI ABDULLAH

4

1 Research Student, River Engineering and Urban Drainage Research Centre (REDAC),

Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia

(Tel: +604-5941035, Fax: +604-5941036, e-mail: [email protected]) 2 Assoc. Prof. & Deputy Director, REDAC, Engineering Campus, Universiti Sains

Malaysia, 14300 Nibong Tebal, Penang, Malaysia

(Tel: +604-5941035, Fax: +604-5941036, e-mail: [email protected]) 3 Assoc. Prof. & Director, REDAC, Engineering Campus, Universiti Sains Malaysia, 14300

Nibong Tebal, Penang, Malaysia

(Tel: +604-5937788, Fax: +604-5941009, e-mail: [email protected]) 4 Assoc. Prof. & Lecturer, School of Civil Engineering, Engineering Campus, Universiti

Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia

(Tel: +604-5937788, Fax: +604-5941009, e-mail: [email protected])

Abstract

Kulim River catchment is located in the southern part of the state of Kedah in the

northwestern corner of Peninsular Malaysia. Kulim River slopes are steep and the channel

elevation drops from 100m down to 18m average mean sea level at the central area of the

Kulim River catchment. Currently, the catchment area is undergoing rapid urban development

with oil palm and rubber plantation being replaced by rapid urbanization and this will result in

discharge and bed erosion increment or scouring and deposition. Frequently floods that occur

in Kulim River Catchment has caused extensive damage and inconvenience to the community

especially floods event in October 2003 which exceeds 100 year ARI. Hence, previous studies

for Kulim River (DID 1996, Yahaya 1999, Lee 2001, Ibrahim 2002, Koey 2003) were

conducted to determine the river behavior and the effectiveness of the flood mitigation

projects due to the rapid urbanization development. However, previous results of sediment

data and river cross section based on the observed data are up to the year 1999. Thus, this

paper describes the analyses and evaluation on sediment transport for Kulim River catchment

by using newly observed data in 2004.

Keywords: Kulim River; Sediment transport; River behavior; Flood mitigation; Bed erosion

1. INTRODUCTION

Effect of rapid urbanization has accelerated impact on the catchment hydrology and

geomorphology. This development which takes place in river catchment areas will cause

dramatic increase in the surface runoff and resulting in higher sediment yield. When this

happens, it not only affects river morphology but cause instability in the river channel and it

1398 September 11~16, 2005, Seoul, Korea

may also cause serious damage to hydraulic structures along the river and reduce the channel

capacity to convey the flood to downstream. Besides, it has also become the main cause for

serious flooding in urban areas. Therefore, it is necessary to predict and evaluate the river

channel stability due to the existing and future development. This study proceeds at Kulim

River in Kedah state, Malaysia, to determine river behaviors and the effectiveness of the flood

mitigation projects due to changes made by nature or human.

2. STUDY AREA

The study area is located at the southern part of the state of Kedah in the northwestern

corner of Peninsular Malaysia (Fig. 1). It lies within the district of Kulim and upstream of

Seberang Perai in Penang. Kulim River catchment consists of 15 subcatchments, with the

total catchment area of 130km2. Kulim river tributaries, include Tebuan River, Kilang Sago

Monsoon Drain, Wang Pinang River, Keladi River and Klang Lama River drain the urban

conurbation of Kulim extending from town to the north. Downstream of Kulim town, the

catchment comprises mainly rubber and oil palm estate located mainly at the confluences of

Kulim River tributaries. The study reach covers about 15km of Kulim River (Fig. 2), from the

upstream (CH 11800) to the state boundary between Kedah and Penang (CH 10) and futher

2.5km downstream at the Ara Kuda gauging station (CH 01). At the headwaters, the Kulim

catchment is hilly and densely forested and Kulim River arises on the western slopes of

Gunung Bongsu Range and flowing in a north-westerly direction, and joined Keladi River in

the vicinity of Kulim town. The river slopes are steep and the channel elevation drops from

500m to 20m average mean sea level (amsl) over a distance of 9km. The central area of the

catchment is undulating with elevations ranging from 100m down to 18m average mean sea

level.

The Kulim Structure Plan, 1990-2010 has outlined development strategies for the region.

Currently the catchment area is undergoing rapid urban development with oil palm and rubber

plantation being replaced by rapid urbanization especially construction for housing estate and

on-going 1450 ha Kulim Hi-Tech industrial Park which will cause impacts to the catchment

due to the increase of impervious area. Flooding at Kulim River has been attributed to

overbank spill from rivers and tributaries arising from a number of causes, such as undersized

river channel and drains to cater flood discharge, high channel roughness, bank irregularity

and in-river vegetation, siltation, blockages by debris and refuse. Siltation at study area has

been identified as one of the common causes of such flooding brought about by soil erosion at

constructions sites. Department of Irrigation and Drainage (DID) Kedah has reported that the

rivers have to be desilted typically every 2 to 3 years with removal of one metre thick of silt

(DID, 1996).

3. STUDY APPROACH

In order to study the sediment transport in the study area, it is important to understand

sediment transport process which is important in solving river engineering problem. However,

the data including river survey geometry data, sediment data and hydrology data were limited


from the previous studies (DID, 1996, Yahaya 1999, Lee 2001, Koey 2003) in Kulim River.

Hence, the result from the present study using newly data up to 2004 will be calibrated and

validated with the present condition and used to predict river stability for future development.

As a result, the main purpose of the present study is to evaluate river stability over a 13 years

period by considering the effect of changes in cross section and sediment size.

3.1 SEDIMENT DATA COLLECTION

Field measurements were obtained along the selected cross section at several study sites at

Kulim River Catchment by using Hydrological Procedure (DID 1976, DID 1979) and recent

manuals (Yuqian 1989, USACE 1995, Edwards & Glysson 1999, Lagasse et al. 2001,

Richardson et al. 2001). A summary of data collection including flow discharge, suspended

load and bed load during April 1999 by Yahaya is shown in Table 1. Data collection

including bed material and bed load have been going on from October to December 2004 and

January 2005 for sediment transport analysis.

3.2 RIVER SURVEY GEOMETRY DATA

The river survey geometry data in September 1991 is provided by Department of Irrigation

and Drainage (DID) Kulim/Bandar Bahru. However, field measurements including bed

elevation, thalweg and water surface were carried out at several cross sections during October

to December 2004.

4. SEDIMENT TRANSPORT ANALYSIS

4.1 SEDIMENT TRANSPORT EQUATION ASSESSMENT

The analysis for a total of 16 set of data from Yahaya (1999) based on average size of

sediment (d50) have been obtained for four sediment transport equations including Yang,

Engelund & Hansen, Ackers & White and Graf equations. The data were analyzed and

evaluated using the above sediment transport equations and the result shows that Graf

equation yielded the highest percentage of discrepancy ratio (0.5 – 2.0) with 44% followed by

Yang equation at 19% (Table 2). These poor performances can be attributed from the

difference in sediment availability from the source, composition of sediment and river

configuration in Malaysia.

Mathematical model, such as FLUVIAL-12 can be used to study sediment transport for a

particular river reach. The model is formulated and developed for water and sediment routing

in man-made or natural channel (Chang 1993). The combined effects of river hydraulics,

sediment transport and river channel changes are simulated for a given flow period. The

accuracy of sediment routing depends on the validity of the sediment transport equation used

in the model. In order to select a equation for sediment routing, Graf, Yang, Engelund-Hansen,

Ackers-White and Meyer-Peter-Muller equation were tested and computed results were

compared with the observed data (DID 1991). The simulation results of FLUVIAL-12

(Manning Roughness Coefficient, n = 0.040) shown in Fig. 3 indicates that revised Ackers-


White equation gives better results which best reproduce the observed river profile for CH

5400 to CH 2600. The study show that the simulation results based on FLUVIAL-12 able to

predict sediment transport for Kulim River.

4.2 BED MATERIAL SIZE DISTRIBUTIONS

The data for bed material were obtained by grab sampling at CH 1000 and CH 01 on April

1999 for the reach 3.5km as shown in Figure 4. Average bed material size (d50) varies from

3.00 mm to 4.00 mm between CH 1000 and CH 01. Figure 5 depicts the field measurement

between October 2004 to January 2005 at CH 11800 (Upstream) and CH 1000 (Downstream).

The average bed material size (d50) varies from 0.95 mm to 0.70 mm between CH 11800 and

CH 1000 for 11.5km reach. The summary of the mean sediment size of bed material is shown

in Table 3. The average mean sediment size (d50) at CH 1000 change from very fine gravel

(3.60mm) to fine sand (0.70mm) over 5 years period. Urbanization and the sand mining

activities in Kulim River catchment may have affected the river equilibrium and caused

variation in sediment distribution along the river.

4.3 TYPICAL CROSS SECTION CHANGES

The comparison between cross section provided by DID (1991) and field measurement

after November 2004 flood show that there has been a change in cross section (Fig. 6). The

channel bed profile has gradually reduced within 13 years period. Thalweg at the CH 11800

has changed from 24.58m to 22.85m and thalweg at the CH 1000 has changed from 15.30m

to 12.00m. The results of cross section changes showed that steep slope in Kulim River has

induced higher discharge. Besides, it is also associated with the spatial variation in sediment

transport. The changes in river bed profile may be attribute to the erosion or deposition along

the banks or the channel width.

5. CONCLUSIONS

River is a dynamic system governed by hydraulic and sediment transport proccess. Over

time, the river response by changing in channel cross section, increased or decreased sediment

carrying capacity, erosion and deposition along the channel, which affect bank stability and

even morphology changes. As a result, sediment size and cross section in Kulim River

subjected to significant changes in a 15km reach over 13 years period. However, in order to

study morphological changes of Kulim River, a long term-simulation by using mathematical

model, FLUVIAL-12 and InfoWorks RS for water and sediment routing, will be developed

and tested with field data up to year 2004. The model, which is applicable to alluvial streams

with erodible banks, may be employed to simulate stream bed and width changes. This paper

has attempted to give an overview of the channel changes and sediment transport phenomena

which cause problems with river bank and bed stability in Kulim River. In general the Kulim

River is in equilibrium or slightly degrading, that is, being deepened by erosion. Therefore, it

is necessary to predict the river channel stability that will happen due to the existing and

future development in Kulim River catchments area. As a result, a design for stable channel


for Kulim River based on the long-term simulation by using FLUVIAL-12 and InfoWorks RS

model will be made.

ACKNOWLEDGEMENTS

The authors gratefully acknowledge Department of Irrigation and Drainage (DID)

Kulim/Bandar Bahru for providing river survey geometry data and all information about

Kulim River catchment and also DID Hydrology & Water Resources Division for providing

hydrology data in this study. The authors would also like to thank all undergraduate and

postgraduate students and REDAC’s staff for their involvement in completion of this paper.

REFERENCES

Chang, H. H. (1993). FLUVIAL-12: Mathematical Model for Erodible Channel. San Diego,

California.

Department of Irrigation and Drainage Malaysia. (1976). River Discharge Measurement By

Current Meter – Hydrological Procedure No. 15

Department of Irrigation and Drainage Malaysia. (1977). The Determination of Suspended

Sediment Discharge – Hydrological Procedure No. 19

Department of Irrigation and Drainage Malaysia. (1996). Study on Flood Mitigation and

Drainage Master Plan for Kulim and its surroundings, Kedah Darul Aman.

Department of Irrigation and Drainage Malaysia. (2003). River Sediment Data Collection and

Analysis Study.

Edwards, T. K. & Glysson G. D. (1999). Field Methods for Measurement of Fluvial Sediment.

U.S. Geological Survey Techniques of Water-Resources Investigations, Book, Chapter C2.

Ibrahim, N. A. (2002). Evaluation and Development of Sediment Transport Equations for

Kinta River Basins, Kulim River and Kerayong River. MSc. Thesis. Penang : Universiti

Sains Malaysia.

Koay, B. C. (2004). Evaluation of River Equilibrium: Case Study of Kulim River. Final Year

Project Thesis. Penang : Universiti Sains Malaysia.

Lagasse, P. F., Schall, J. D. & Richardson, E. V. (2001). Stream Stability at Highway

Structures, US Department of Transportation, Federal Highway Administration.

Publication No. FHWA NHI 01-002 (Hydraulic Engineering Circular No. 20), 3rd Edition

Lee, C. B. (2001). Application of River Modeling (Fluvial-12): Case Studies of Kulim River

and Melaka River. Final Year Project Thesis. Penang : Universiti Sains Malaysia.

Richardson, E. V., Simons, D. B. & Lagasse, P. F. (2001). River Engineering for Highway

Encroachments – Highways in The River Enviroment, US Department of Transportation,

Federal Highway Administration. Publication No. FHWA NHI 01-004 (Hydraulic Design

Series Number 6).

United States Army Corps of Engineers. (1995). Sedimentation Investigations of Rivers And

Reservoirs. USACE Engineering and Design Manual. Publication No. EM 1110-2-4000.


Yahaya, N. K. (1999). Development of Sediment Rating Curves for Rivers In Malaysia: Case

Studies of Pari, Kerayong and Kulim Rivers. MSc. Thesis. Penang : Universiti Sains

Malaysia.

Yuqian, L. (1989). Manual On Operational Methods for The Measurement of Sediment

Transport. World Meteorological Organisation – Operational Hydrology Report No. 29.


Table 1. Range of Field Data for Yahaya (1999)

No. of

Sample Discharge, Width, d50

Bed

Load

Transport

Suspende

d Load

Transport

Total

Load

Transport Study Site

Q (m3/s) B (m) (mm) Qb (kg/s) Qt (kg/s) Qj (kg/s)

Kulim

River 16 1.39 - 11.14

14.0 -

18.0 3.00 - 4.00

0.07 -

0.34

0.26 -

6.78

0.34 -

7.08

Table 2. Summary of Sediment Transport Assessment (16 Data) (Yahaya, 1999).

Discrepancy Ratio (0.5 – 2.0) Equation

No. of data Percentage

Yang 3 19

Engelund & Hansen 0 0

Ackers & White 0 0

Graf 7 44

Table 3. Summary of Mean Sediment Size

d50 (mm) Location

No. of data Range Average

Upstream CH 1000 (Apr 1999) 8 3-4 3.60

Downstream CH 0 (Apr 1999) 8 3.55 – 4 3.75

Upstream CH 11800 (2004) 2 0.7-1.2 0.95

Downstream CH 1000 (2004) 4 0.55-0.85 0.70

Fig. 1 Kulim River Catchment and Subcatchment (DID, 1996)

Peninsular Malaysia

Study Area


Fig. 2 Kulim River Study Reach

Fig. 3 Simulated bed profile using FLUVIAL-12 model compared to obseved bed profile

9.5

10.0

10.5

11.0

11.5

12.0

12.5

13.0

13.5

14.0

14.5

2600

2700

2800

2900

3000

3100

3200

3300

3400

3500

3600

3700

3800

3900

4000

4100

4200

4300

4400

4500

4600

4700

4800

4900

5000

5100

5200

5300

5400

Section No. (CH)

Bed

Elevation (m)

Observed (September 1991)

Engelund-Hansen

Graph

Meyer-Peter Muller

Yang

Ackers-White

Manning’s n = 0.040

CH 5900

CH 11800 Upstream

CH 01

CH 1000

CH 10

CH 3000

CH 8200


(a) Upstream (CH 11800)

(b) Downstream (CH 1000)

Fig. 6 Typical cross section at at CH 11800 and CH 1000 along Kulim River


0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

0.01 0.10 1.00 10.00 100.00

Partical Size (mm)

Percentage Passing (%)

01.04.1999

02.04.1999

03.04.1999

04.04.1999

05.04.1999

06.04.1999

07.04.1999

08.04.1999

Average

(a) CH 1000 (Upstream)

(b) CH 01 (Downstream)

Fig. 4 Distribution of bed material (Yahaya, 1999)

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

0.01 0.10 1.00 10.00 100.00

Partical Size (mm)


01.04.1999

02.04.1999

03.04.1999

04.04.1999

05.04.1999

06.04.1999

07.04.1999

08.04.1999

Average


(a) CH 11800 (Upstream)

(b) CH 1000 (Downstream)

Fig. 5 Distribution of bed material from field measurement between October

and December 2004, and January 2005.

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

0.01 0.10 1.00 10.00 100.00

Partical Size (mm)


08.12.2004

11.01.2005

Average

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

0.01 0.10 1.00 10.00 100.00

Partical Size (mm)


06.10.2004 (10.00am)

06.10.2004 (02.30pm)

08.12.2004

11.01.2005

Average

sediment transport in kulim river, malaysiaredac.eng.usm.my/html/publish/2005_09.pdf · 2019. 10....

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