Flood Hazard Assessment along the Western Regions of Saudi Arabia using GIS-based ...

103 Pages·2014·5.72 MB·English

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Flood Hazard Assessment along the Western Regions of Saudi Arabia
using GIS-based Morphometry and Remote Sensing Techniques

Thesis by
Qianwen Shi

In Partial Fulfillment of the Requirements
For the Degree of
Master of Science

King Abdullah University of Science and Technology
Thuwal, Kingdom of Saudi Arabia

December 2014
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The thesis of Qianwen Shi is approved by the examination committee.

Committee Chairperson: Dr. Matthew Francis McCabe
Committee Member: Dr. Peiying Hong
Committee Member: Dr. Sigurjón Jónsson
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© December 2014
Qianwen Shi
All Rights Reserved
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ABSTRACT
Flood Hazard Assessment along the Western Regions of Saudi Arabia using GIS-based
Morphometry and Remote Sensing Techniques
Qianwen Shi
Flash flooding, as a result of excessive rainfall in a short period, is considered as one of
the worst environmental hazards in arid regions. Areas located in the western provinces
of Saudi Arabia have experienced catastrophic floods. Geomorphologic evaluation of
hydrographic basins provides necessary information to define basins with flood hazard
potential in arid regions, especially where long-term field observations are scarce and
limited. Six large basins (from North to South: Yanbu, Rabigh, Khulais, El-Qunfza,
Baish and Jizan) were selected for this study because they have large surface areas and
they encompass high capacity dams at their downstream areas. Geographic Information
System (GIS) and remote sensing techniques were applied to conduct detailed
morphometric analysis of these basins. The six basins were further divided into 203 sub-
basins based on their drainage density. The morphometric parameters of the six basins
and their associated 203 sub-basins were calculated to estimate the degree of flood hazard
by combining normalized values of these parameters. Thus, potential flood hazard maps
were produced from the estimated hazard degree. Furthermore, peak runoff discharge of
the six basins and sub-basins were estimated using the Snyder Unit Hydrograph and three
empirical models (Nouh’s model, Farquharson’s model and Al-Subai’s model) developed
for Saudi Arabia. Additionally, recommendations for flood mitigation plans and water
management schemes along these basins were further discussed.
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ACKNOWLEDGEMENTS
I would like to express my sincere gratitude to my committee chair, Prof. Matthew
McCabe, who has given me a lot of guidance and support throughout the course of this
research. Prof. McCabe’s insights and encouragement of critical thought provided me
with an interesting and unique research experience. His training has enabled me to
achieve better understanding of a topic I would never have achieved on my own.
I would like to thank Dr. Abdou A. Abouelmagd, who was very patient and gave answers
to my questions. He helped me with the data collection and software application during
this research. I had a great learning experience with him.
I would also like to thank Prof. Peiying Hong and Prof. Sigurjón Jónsson for being part of
my thesis defense committee and for their time.

My appreciation also goes to the members of Earth System Observation and Modeling,
for their appreciable help during this research. I want to thank my professors, friends,
colleagues and the department faculty and staff, for making my time at King Abdullah
University of Science and Technology a great experience.
Finally, but not least, my heartfelt gratitude is extended to my parents for their
encouragement and support.
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TABLE OF CONTENTS
Page
EXAMINATION COMMITTEE APPROVALS FORM .......................................... 2
COPYRIGHT PAGE ................................................................................................. 3
ABSTRACT ............................................................................................................... 4
ACKNOWLEDGEMENTS ....................................................................................... 5
TABLE OF CONTENTS ........................................................................................... 6
LIST OF ABBREVIATIONS .................................................................................... 9
LIST OF SYMBOLS ................................................................................................. 10
LIST OF ILLUSTRATIONS ..................................................................................... 11
LIST OF TABLES ..................................................................................................... 14
CHAPTER 1. INTRODUCTION .............................................................................. 15
1.1 Ari Zone and Wadi Systems ......................................................... 15
1.2 Flood Hazard of Wadis ................................................................. 16
1.3 Morphometric Study ..................................................................... 17
1.4 Geographic Information System ................................................... 18
1.5 Objectives ..................................................................................... 20
CHAPTER 2. LITERATURE REVIEW ................................................................... 21
2.1 Basin Morphometry and flood hazard assessment........................ 21
2.2 Peak Discharge Estimation ........................................................... 23
CHAPTER 3. METHODOLOGY ............................................................................. 26
3.1 Study Area .................................................................................... 26
3.2 Data Sources ................................................................................. 27
3.3 GIS Work Flow ............................................................................. 27
3.4 Morphometric Analysis ................................................................ 31
3.4.1 Drainage Density (D) ......................................................... 32
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3.4.2 Drainage Frequency (F) ..................................................... 32
3.4.3 Length of Overland Flow (L ) ........................................... 32
o
3.4.4 Bifurcation Ratio (R ) ........................................................ 33
b
3.4.5 Form Factor (R) ................................................................ 33
f
3.4.6 Circularity Ratio (R ) ......................................................... 34
c
3.4.7 Elongation Ratio (R ) ......................................................... 34
e
3.4.8 Basin Relief (H) ................................................................. 34
3.4.9 Relief Ratio (R ) ................................................................ 34
h
3.4.10 Ruggedness Number (R) .................................................. 35
3.5 Flood Hazard Index ....................................................................... 36
3.6 Peak Discharge Estimation ........................................................... 37
3.6.1 Snyder Unit Hydrograph ..................................................... 38
3.6.2 Other Empirical Approaches ............................................... 39
3.7 Annual Rainfall Calculation ......................................................... 40
CHAPTER 4. RESULTS ........................................................................................... 43
4.1 Basin Descriptions ........................................................................ 43
4.1.1 Yanbu Basin ........................................................................ 43
4.1.2 Rabigh Basin ....................................................................... 44
4.1.3 Khulais Basin ...................................................................... 45
4.1.4 El-Qunfza Basin .................................................................. 46
4.1.5 Baish Basin ......................................................................... 47
4.1.6 Jizan Basin .......................................................................... 48
4.2 Morphometric Analysis ............................................................... 49
4.2.1 Analysis of the Six Basins .................................................. 49
4.2.2 Analysis of the Sub-Basins ................................................. 61
4.3 Flood Hazard Maps ...................................................................... 62
4.4 Peak Discharge Estimation .......................................................... 66
4.5 Recommendations for Water Management Plans ........................ 72
CHAPTER 5. DISCUSSION ..................................................................................... 74
5.1 Limitations of Flood Hazard Index .............................................. 74
5.2 Feasibility of Peak Discharge Estimation .................................... 75
5.3 Annual Rainfall Variability.......................................................... 76
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CHAPTER 6. CONCLUSIONS ................................................................................ 78
6.1 Future Research Work ................................................................. 79
REFERENCES .......................................................................................................... 80
APPENDICES ........................................................................................................... 89
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LIST OF ABBREVIATIONS

DEM digital elevation model
EOSDIS Earth Observing System Data and Information System
GDEM2 Global Digital Elevation Model Version 2
GIS Geographic Information System
HEC-HMS Hydrologic Engineering Center-Hydrologic Modeling System
LP DAAC Land Processes Distributed Active Archive Center
MOWE Ministry of Water and Electricity
MTM modified Talbot method
NASA National Aeronautics and Space Administration
NRCS National Resources Conservation Service
PET potential evapotranspiration
PRM probabilistic rational method
RFFA regional flood frequency analysis
SCS Soil Conservation Service
SUH Snyder unit hydrograph
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LIST OF SYMBOLS

A surface area of the drainage basin
P perimeter of the drainage basin
Z elevation of the drainage basin
S slope of the drainage basin
L maximum length of the drainage basin
b
U stream order
N stream number with order u
u
L stream length with order u
u
D drainage density
F drainage frequency
L length of overland flow
o
R bifurcation ratio
b
R form factor
f
R elongation ratio
e
H basin relief
R relief ratio
h
R ruggedness number
t basin lag time
l
Q peak discharge
p
L length of the main channel extended to the basin divide
L length of the main channel to the centroid point
c