A Study of Assessment Variability of Annual Daily Maximum Rainfall of Pahang, Malaysia
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ii A STUDY OF ASSESSMENT VARIABILITY OF ANNUAL DAILY MAXIMUM RAINFALL OF PAHANG, MALAYSIA IZYAN SHAHIRAH AIMI BINTI SHAHARUDDIN Report submitted in fulfillment of the requirements for the award of the degree of Bachelor of Engineering (Hons) in Civil Engineering Faculty of civil Engineering and Earth Resources UNIVERSITI MALAYSIA PAHANG JUNE 2015 vi ABTRACT This paper deals with a study on rainfall characteristics of Pahang, for the period 1998 to 2013. In December 2014 flooding caused by torrential rainfall had drowned the main roads in the state of Pahang. As a result, the operating aid to flood victims face difficulties. The main objective of this study was to asses the variability of annual daily maximum rainfall. Daily rainfall data from satellite images Tropical Rainfall Measuring Mission (TRMM) downloaded from a database of public domain. Then daily rainfall data for each major city in the state of Pahang retrieved using Geographic Information System (GIS). Gumbel distribution function were applied to estimate expected return period of extreme rainfall event. Most cities in the State receiving the highest number of monthly maximum annual rainfall during northeast monsoon (November to January). Daily rainfall is equal to or greater than 347 mm have a return period of 13 years each for Rompin, Pekan and Kuantan. However, every year the town in Pahang will receive daily maximum rainfall 37.85 mm to 128.49 mm. The results of this study can be used in a better understanding of the patterns of rainfall in the state of Pahang and can also be used as a guideline in planning the construction of infrastructure in the future. vii ABSTRAK Kajian ini membincangkan mengenai ciri-ciri curahan hujan Negeri Pahang, bagi tempoh 1998 hingga 2013. Pada Disember 2014 banjir yang disebabkan oleh curahan hujan yang lebat telah menenggelamkan jalan-jalan utama di Negeri Pahang. Akibatnya, operasi bantuan kepada mangsa banjir menghadapi kesukaran. Objektif utama kajian ini adalah untuk menilai kepelbagaian curahan hujan maksimum harian tahunan Negeri Pahang. Data curahan hujan harian dari imej satelit Tropical Rainfall Measuring Mission (TRMM) dimuat turun dari pangkalan data domain awam. Kemudian data curahanhujan harian bagi setiap bandar utama di Negeri Pahang diterbitkan menggunakan teknik Sistem Maklumat Geografi (GIS). Gumbel Distribution Function telah digunakan untuk menganggarkan tempoh ulangan jangkaan peristiwa curahan hujan harian yang tertinggi. Kebanyakan bandar di Negeri Pahang menerima jumlah tertinggi hujan tahunan maksimum bulanan pada monsun timur laut (November hingga Januari). Hujan harian yang sama atau lebih daripada 347 mm mempunyai tempoh pulangan 13 tahun masing-masing untuk Rompin, Pekan dan Kuantan. Walau bagaimanapun, setiap tahun bandar di Negeri Pahang akan menerima hujan maksimum harian 37.85 mm hingga 128.49 mm. Hasil kajian ini boleh digunakan dalam pemahaman yang lebih baik tentang corak hujan di Negeri Pahang dan boleh juga untuk dijadikan garis panduan dalam perancangan pembinaan infrastruktur di masa akan datang. viii TABLE OF CONTENT CHAPTER TITLE PAGE SUPERVISOR’S DECLARATION ii STUDENT’S DECLARATION iii DEDICATION iv ACKNOWLEDGEMENT v ABSTRAK vi ABSTRACT vii TABLE OF CONTENTS viii LIST OF TABLES xii LIST OF FIGURES xiii LIST OF SYMBOLS xv LIST OF ABBREVIATIONS xvi CHAPTER 1 INTRODUCTION 1.1 Background of Study 1 1.2 Problem Statement 4 1.3 Objectives 5 1.4 Scope of Study 5 1.5 Significance of Study 7 1.6 Thesis Structure 8 CHAPTER 2 LITERATURE REVIEW ix 2.1 Introduction 9 2.2 Study Area 11 2.2.1 General Climate of Negeri Pahang 12 2.2.1.1 Rainfall Distribution 13 2.3 Flood Event in Negeri Pahang 13 2.4 Rainfall Types 15 2.4.1 Convective Rainfall 15 2.4.2 Orographic Rainfall 16 2.4.3 Cyclonic Rainfall 17 2.5 Return Periods 19 2.6 Satellite Rainfall Data 20 2.7 Summary 20 CHAPTER 3 METHODOLOGY 3.1 Introduction 22 3.2 Data Collecting 24 3.3 Pre-Processing 25 3.3.1 Sub-Set Coordinate into GIS Ready Data 25 3.3.2 GeoTIFF Export 26 3.3.3 Export Raster Data and Clip Data 27 3.3.4 Extract Value to Point 29 3.4 Processing 30 3.5 Summary 32 CHAPTER 4 RESULTS AND DISCUSSION 4.1 Introduction 33 x 4.2 Rainfall Characteristics 33 4.2.1 Rainfall Characteristics of Rompin City 34 4.2.2 Rainfall Characteristics of Pekan City 35 4.2.3 Rainfall Characteristics of Kuantan City 36 4.2.4 Rainfall Characteristics of Maran City 37 4.2.5 Rainfall Characteristics of Bera City 38 4.2.6 Rainfall Characteristics of Bentong City 39 4.2.7 Rainfall Characteristics of Temerloh 40 City 4.2.8 Rainfall Characteristics of Raub City 41 4.2.9 Rainfall Characteristics of Kuala Lipis 42 City 4.2.10 Rainfall Characteristics of Jerantut City 43 4.2.11 Rainfall Characteristics of Cameron 44 Highland City 4.3 Extreme Rainfall Events 45 4.4 Return Periods of Annual Daily Maximum 46 Rainfall 4.4.1 Return Periods of Annual Daily 47 Maximum Rainfall of Rompin 4.4.2 Return Periods of Annual Daily 48 Maximum Rainfall of Pekan 4.4.3 Return Periods of Annual Daily 49 Maximum Rainfall of Kuantan 4.4.4 Return Periods of Annual Daily 50 Maximum Rainfall of Maran 4.4.5 Return Periods of Annual Daily 51 Maximum Rainfall of Bera 4.4.6 Return Periods of Annual Daily 52 Maximum Rainfall of Bentong 4.4.7 Return Periods of Annual Daily 53 Maximum Rainfall of Temerloh 4.4.8 Return Periods of Annual Daily 54 xi Maximum Rainfall of Raub 4.4.9 Return Periods of Annual Daily 55 Maximum Rainfall of Kuala Lipis 4.4.10 Return Periods of Annual Daily 56 Maximum Rainfall of Jerantut 4.4.11 Return Periods of Annual Daily 57 Maximum Rainfall of Cameron Highland 4.5 Summary 58 CHAPTER 5 CONCLUSIONS AND RECOMMENDATIONS 5.1 Conclusions 59 5.2 Recommendations 60 REFERENCES 62 APPENDICES 64 xii LIST OF TABLES TABLE NO. TITLE PAGE 3.1 Coordinate of each cities in Pahang 24 4.1 Descriptive statistics of rainfall pattern of Rompin City 34 4.2 Descriptive statistics of rainfall pattern of Pekan City 35 4.3 Descriptive statistics of rainfall pattern of Kuantan City 36 4.4 Descriptive statistics of rainfall pattern of Maran City 37 4.5 Descriptive statistics of rainfall pattern of Bera City 38 4.6 Descriptive statistics of rainfall pattern of Bentong City 39 4.7 Descriptive statistics of rainfall pattern of Temerloh City 40 4.8 Descriptive statistics of rainfall pattern of Raub City 41 4.9 Descriptive statistics of rainfall pattern of Kuala Lipis City 42 4.10 Descriptive statistics of rainfall pattern of Jerantut City 43 4.11 Descriptive statistics of rainfall pattern of Cameron 44 Highland City 4.12 Historical extreme rainfall events of cities in Pahang. 45 xiii LIST OF FIGURES FIGURE NO. TITLE PAGE 1.1 Flood in Sungai Lembing 2 1.2 Flood in Temerloh 2 1.3 Location of each cities in Pahang 6 2.1 Hydrologic Cycle 10 2.2 Location of Pahang in Malaysia 12 2.3 Convective Rainfall 16 2.4 Orographic Rainfall 17 2.5 Cyclonic Rainfall 18 3.1 Flow Chart of the Project Methodology 23 3.2 Location of each cities in Pahang 25 3.3 The raw rainfall data is ready to export 26 3.4 GeoTIFF Export 27 3.5 Export raster data 28 3.6 Clip data 28 3.7 Extract values to point 29 3.8 Attribute of extract values 30 4.1 Return periods of annual daily maximum rainfall of Rompin 47 City. 4.2 Return periods of annual daily maximum rainfall of Pekan 48 City 4.3 Return periods of annual daily maximum rainfall of Kuantan 49 City 4.4 Return periods of annual daily maximum rainfall of Maran 50 City 4.5 Return periods of annual daily maximum rainfall of Bera 51 City xiv 4.6 Return periods of annual daily maximum rainfall of Bentong 52 City 4.7 Return periods of annual daily maximum rainfall of 53 Temerloh City 4.8 Return periods of annual daily maximum rainfall of Raub 54 City 4.9 Return periods of annual daily maximum rainfall of Kuala 55 Lipis City 4.10 Return periods of annual daily maximum rainfall of Jerantut 56 City 4.11 Return periods of annual daily maximum rainfall of 57 Cameron Highland City xv LIST OF SYMBOLS y First moment S2 Second moment x Annual daily maximum rainfall ξ Shape σ Standard deviation μ mean F(x) Cumulative probability distribution P(x) Probability distribution N Return periods xvi LIST OF ABBREVIATIONS GIS Geographical Information System NEM Northeast Monsoon SWM Southwest Monsoon TRMM Tropical Rainfall Measuring Mission 1 CHAPTER 1 INTRODUCTION 1.1 Background of Study In December 2014 floods have submerged main roads of the city in the state of Pahang. Consequently, the main road between the cities in Pahang were cut off. This makes it difficult to deliver aid quickly to the city that affected by the floods. In addition, rainfall during the northeast monsoon is often associated with the occurrence of floods in major cities in Pahang. For example, in 18 December 2014, the rain continued throughout the day caused flooding in several road around Kuantan district (JKR Pahang, 2015). Figure 1.1 shows flooding that occured in Sungai Lembing. In 12 January 2015, flooding in Temerloh became serious when water levels of Pahang River rise up spilling into the streets and villages nearby which caused the road access between Temerloh and Bera disconnected and also road access to Jerantut (JKR Daerah Temerloh, 2015).