STUDY ON BACKWATER IMPACT OF KUCHING BARRAGE Dayang Harom Awang Sam Bachelor of Engineering with Honours TC (Civil Engineering) 175 D273 2009 2009 Universiti Malaysia Sarawak Kota Samarahan tk BORANG PENYERAHAN TESIS Judul: STUDY ON BACKWATER IMPACT OF KUCHING BARRAGE SESI PENGAJIAN: 2005 - 2009 Saya DAYANG HARONI AW ANG SANI (HURUF BESAR) mengaku membenarkan laporan projek ini disimpan di Pusat Khidmat Maklumat Akademik, Universiti Malaysia Sarawak dengan syarat-syarat kegunaan seperti berikut: I. Hakmilik kertas projek adalah di bawah nama penulis melainkan penulisan sebagai projek bersama dan dibiayai oleh UNIMAS, hakmiliknya adalah kepunyaan UNIMAS. 2. Naskhah salinan di dalam bentuk kertas atau milcro hanya boleh dibuat dengan kebenaran bertulis daripada penulis. 3. Pusat Khidmat Maklumat Akademik, UNIMAS dibenarkan membuat salinan untuk pengajian mereka. 4. Kertas projek hanya boleh diterbitkan dengan kebenaran penulis.Bayaran royalti adalah mengikut kadar yang dipersetujui kelak. 5. * Saya membenarkanltidak membenarkan Perpustakaan membuat salinan kertas projek ini sebagai bahan pertukaran di antara institusi pengaj ian tinggi. 6. ** Sila tandakan (" ) c=J SULIT (Mengandungi maklumat yang berdwjah keselamatan atau kepentingan Malaysia seperti yang termaktub di dalam AKTA RAHSIA RASMI 1972). c=J TERHAD (Mengandungi maklumat TERHAD yang telah ditentukan oleh organisasil badan di mana penyelidikan dijalankan). 1c=J TIDAK TERHAD ~. (TANDA T ANGAN PENULIS) Alamat tetap: LOT 1679, LORONG B 26, KAMPUNG MUHIBBAH, PROF. DR F. J. PUTUHENA ( Nama Penyelia ) 95000 SRI AMAN, SARAW AK I Tarikh: Tarikh: CATATAN * Potong yang tidak berkenaan. ** Jika Kertas Projek ini SULIT atau TERHAD, sila lamplrkan surat daripada pihak berkuasal organisasi berkenaan deogan menyertakao sekali tempoh kertas projek. Ini perlu dikelaskan sebagai SULIT atau TERHAD. PKSl2000 The following Final Year Project Report: Title STUDY ON BACKWATER IMPACT OF KUCHING BARRAGE Name : DAYANG HARONI A WANG SANI Matric No. : 13937 has been read and approved by: PROF. DR. F.J. PUTUHENA Date Project Supervisor STUDY ON BACKWATER IMPACT OF KUCHING BARRAGE DAYANG HARONI AWANG SANI This project is submitted in partial fulfillment of the requirements for degree of Bachelor of Engineering with Honours (Civil Engineering) 2009 Faculty ofEngineering UNIVERSITI MALAYSIA SARAWAK 2009 Dedicated to my beloved family members, friends, and all parties involved. 11 ACKNOWLEDGMENT Firstly, I would like to express appreciation to God for giving me the strength along the completion of this project. I also want to express my thanks to my supervisor, Prof. Dr. Frederik Josep Putuhena for his guidance and assistance along with the completion of this project. I want to acknowledge the staffs in the Hydrological Section of Department of Irrigation and Drainage, Kuching, Sarawak for their cooperation in providing the data required in this project. I wish to acknowledge to Darrien Mah Yau Seng for his considerable time and assistance in helping me for my study. My special thanks also dedicated to my beloved family members and friends for their motivation and moral support. Lastly, my thanks also dedicated to those who are involved either directly and indirectly in this project. III ABSTRAK Kuching Barrage telah dibina di Sungai Sarawak dan mempunyai lima pintu jejari dan untuk mengawal tahap air sungai di Sungai Sarawak dan satu pintu kapal. Semasa hujan lebat, pintu-pintu sekatan akan buka sepenuhnya untuk mengalirkan air hujan yang berlebihan bergantung kepada tahap air laut. Penyelidikan ini telah menghasilkan model-model simulasi untuk beberapa scenario banjir supaya dapat menganalisis backwater impact di Sungai Sarawak yang berpunca dari operasi Kuching Barrage. Langkah-Iangkah ketja dan pendekatan model hidrodinamik dengan menggunakan perisian Geographical Information System (GIS) and Info Works River Simulation (RS) telah diguna untuk simulasi-simulasi banjir. Scenario banjir yang dibincangkan adalah seperti keadaan banjir semasa pintu sekatan ditutup atau dibuka, aliran air sungai yang sekata, semasa ombak tinggi dan rendah, peristiwa banjir yang kecil dan besar. Peta banjir dibina untuk menilai backwater impact di Sungai Sarawak semasa peristiwa banjir berlaku. Kawasan tadahan Sungai Maong dipilih untuk menyelidik perbezaan backwater impact di Sungai Sarawak dengan mengukur panjang jalan yang dibanjiri air. Profil-profil banjir dihasilkan dengan menggunakan Info Work RS. Kesan positif dan negatif backwater impact juga telah dibincangkan. Keputusan-keputusan daripada penyelidikan ini menunjukkan bahawa operasi Kuching Barrage, tahap tinggi ombak, dan aliran air sungai mempengaruhi backwater impact di Sungai Sarawak. iv ABSTRACT Kuching Barrage has been constructed and comprises of five radial gates controlling Sarawak River water level and a ship lock. At times of heavy stonn, barrage gates will be fully opened to discharge the excess stonn water depends on sea water level. This study had generated simulations model for several flood scenarios to analyse and identify the backwater impact of Sarawak River due to Kuching Barrage operations. The methodology and hydrodynamic modeling approach using Geographical Infonnation System (GIS) and InfoWorks River Simulation (RS) softwares had been developed for flood simulations. The flood scenarios that been discussed comprising when barrage gates is closed and open, with average river flows during high tides and low tides, small flood event and extreme flood event. The flood mappings were developed to evaluate the backwater impacts in Sarawak River during flood event. Maong River catchments areas were chosen to study the differences of backwater impact of Sarawak River by measures the length of roads inundated. The flood profiles had been generated by Info Work RS. The positive and negative of backwater impacts were discussed. The results of this study had shown that the barrage operations, tide levels and river flows had influenced the backwater in Sarawak River. v LIST OF TABLES Tables Page Number 1.1 Historical Flood Events Recorded in Sarawak from 2 year 1962-1999, before the operation of barrage 1.2 Historical Flood Events Recorded in Sarawak from 3 year 2000-2007, after the operation ofbarrage 4.15 Summary ofComparison ofScenarios 59 VI LIST OF FIGURES " Figures Page Number 2.1 Location of Kuching Barrage 10 2.2 Kuching Barrage 11 2.3 Radial Gate ofKuching Barrage Cross Section 11 2.4 Marina Barrage Cross Section 13 2.5 Marina Barrage Operation 14 2.6 Thames Barrier 15 2.7 Scheme for Equation of Continuity 21 2.8 Scheme for Equation of Energy in a cross section 25 2.9 Scheme of the Equation of Energy between two sections 27 2.10 Hydraulic Scheme ofa Weir 31 2.11 Floodplain 33 2.12 Relationship of Fundamental of Flood Reduction Studies 33 3.1 Model Development by GIS 39 3.2 Calibration of2003 Flood Level at Upstream and 41 Downstream of Barrage 3.3 Calibration of February Flood at Upstream ofShiplock 42 1 vii 3.4 Calibration of February Flood at Satok Bridge 42 3.4 Calibration of February Flood at Batu Kawa Bridge 43 4.1 Flood Mapping during Barrage Gates is closed up to 47 1.9m 4.2 Flood Profile during Barrage Gates is closed 47 4.3 Flood Mapping during High Tides and Low Tides 49 for Scenario 2 4.4 Comparison of Flood Mapping of Maong River 49 Catchments Area during High Tides and Low Tides for Scenario 2 4.5 Flood Profile during High Tides for Scenario 2 50 4.6 Flood Profile during Low Tides for Scenario 2 51 4.7 Flood Mapping during High Tides and Low Tides 52 for Scenario 3 4.8 Comparison of Flood Mapping of Maong River 53 Catchments Area during High Tides and Low Tides for Scenario 3 4.9 Flood Profile during High Tides for Scenario 3 54 4.10 Flood Profile during Low Tides for Scenario 3 54 4.11 Flood Mapping during High Tides and Low Tides 56 for Scenario 4 V1l1 ,.. 4.12 Comparison of Flood Mapping of Maong River 57 Catchments Area during High Tides and Low Tides for Scenario 4 4.13 Flood Profile during High Tides for Scenario 4 58 4.14 Flood Profile during Low Tides for Scenario 4 58 I' I ix ,.... Pusat Kludmal wnal iJt. UNIVER.S ITf MALAYSIA SARAWAK TABLE OF CONTENTS Page Number Acknowledgment III Abstrak IV Abstract V List ofTables VI List of Figures VII Chapter 1 INTRODUCTION 1.1 Background of Study 1 1.2 Statements of Problem 4 1.2.1 Flood after Kuching Barrage Operation 4 1.2.2 Backwater impact due to the Barrage Operation 5 1.3 Objectives 6 1.4 Scope of Work 6 1.5 Organization of Report 7 Chapter 2 LITERATURE REVIEW 2.1 Barrage 9 2.1.1 Kuching Barrage 9 x ,.. II 2.1.2 Marina Barrage 12 2.1.3 Thames Barrier 15 2.2 Backwater Impact 19 2.2.1 Equation of Continuity 21 I' 2.2.2 Equation ofEnergy 24 2.2.3 Flow Over Weir 29 2.3 Flood Mitigation 32 2.4 Application of Geographical Information System (GIS) 35 2.5 Application of Info Work River Simulation (RS) 37 Chapter 3 METHODOLOGY 3.1 Backwater Development 38 3.2 Initial and Boundary Conditions 39 3.3 Calibrations of Model 40 I' 3.4 Flood Simulation and Mapping 43 Chapter 4 RESULTS AND DISCUSSION 4.1 General 45 4.2 Flood Simulation Results 46 4.2.1 Scenario 1 : High Tides and the Barrage Gates 46 I is Closed 4.2.2 Scenario 2: Average Flows, High Tides, 48 and Low Tides xi 4.2.3 Scenario 3 : Small Flood Events, High Tides, 52 and Low Tides 4.2.4 Scenario 4 : Extreme Flood Events, High Tides, 56 and Low Tides 4.3 Discussions 59 Chapter 5 CONCLUSIONS AND RECOMMENDATIONS 5.1 Conclusions 61 5.2 Recommendations for Future Study 62 REFERENCES 63 Xll CHAPTERl INTRODUCTION 1.1 Background of Study Kuching city is located on the Sarawak River. Some division of the Kuching city js located in very flat and low lying area, thus the probability to subject of significant tidal action and susceptible to river flooding are high.