Application of GIS in Flood Hazard Mapping - GIS I Fundamentals - CEI40 - AGA

9-Month Program, Intake40, CEI Track
GEOGRAPHIC INFORMATION SYSTEMS I - FUNDAMENTALS
Application of GIS in
Flood Hazard Mapping
Ahmed Gamal Abdel Gawad

 TEACHING ASSISTANT AT MENOUFIYA UNIVERSITY.
 GRADE: EXCELLENT WITH HONORS.
 BEST MEMBER AT ‘UTW-7 PROGRAM’, ECG.
 ITI 9-MONTH PROGRAM, INT40, CEI TRACK STUDENT.
 AUTODESK REVIT CERTIFIED PROFESSIONAL.
 BACHELOR OF CIVIL ENGINEERING, 2016.
 LECTURER OF ‘DESIGN OF R.C.’ COURSE, YOUTUBE.
ABOUT ME

CONTENTS
Overview
GIS Basics
Water Resources Engineering
GIS and Water Resources
Flood Hazard Mapping
Research Paper
Flood mapping in ArcGIS

Overview
 A geographic information system (GIS) is a framework for
gathering, managing, and analyzing data.
 Rooted in the science of geography, GIS integrates many
types of data. It analyzes spatial location and organizes
layers of information into visualizations using maps and 3D
scenes.
 With this unique capability, GIS reveals deeper insights
into data, such as patterns, relationships, and situations—
helping users make smarter decisions.
6

Overview
 Geographic information systems (GIS) have become an
increasingly important means for understanding and dealing
with the pressing problems of water and related resources
management in our world.
 GIS concepts and technologies help us collect and organize the
data about such problems and understand their spatial
relationships.
 GIS analysis capabilities provide ways for modeling and
synthesizing information that contribute to supporting decisions
for resource management across a wide range of scales, from
local to global.
7

Overview
 A GIS also provides a means for visualizing resource
characteristics, thereby enhancing understanding in support of
decision making.
 Several definitions of GIS are offered to introduce the concepts
and technologies that comprise GIS. A general overview of GIS
involves the technologies for data capture and conversion, data
management, and analysis.
 Also, there is a need to be aware of the management
dimensions of GIS, as implementation of GIS can require basic
changes in the way engineering planning and design are
accomplished.
8

Applications for GIS
 Business
 Military & Defense
 Scientific Research
 Real Estate & Marketing
 Transportation
 Urban Planning & Management
 Civil Engineering/Utility
 Environmental Sciences
 Health Care
 Political Science
9

Geographical Information System
 A Geographic Information System (GIS) can be defined as a
system of hardware, software, data and organizational
structure for collecting, storing, manipulating and
analyzing spatially related or 'geo-referenced' data and
presenting information resulting from the analysis.
12

A more detailed definition introduces GIS as: "any
Information system which can:
 Collect, store and retrieve information based on its spatial
locations;
 Identify locations within a targeted environment which
meet specific criteria;
 Explore relationships among data sets within that
Environment;
13

A more detailed definition introduces GIS as: "any
Information system which can:
 Analyze the related data spatially as an aid to making
decisions;
 Facilitate selecting and passing data to applications-
specific analytical models capable of assessing the impact
of alternatives, and
 Display the selected environment both graphically and
numerically either before or after analysis“.
14

Information Systems
Information systems are:
 Dominant tool.
 Set of computer programs that are
used to input (encode) information
and store it in a structured manner.
 Information can be retrieved,
analyzed and, finally, reported as a
table, graph, map or picture.
15

Importance of Information
Knowledge is power:
 Information enables controlling a
problem parameters.
 With perfect information, optimal
decisions can be made.
 If it is Impossible to be perfectly
informed, so decisions are expected
to be imperfect.
16

Spatial Information
 Spatially related information refers
to location on the earth that can be
represented by latitude, longitude
and altitude.
 Between 70 and 80% of the digital
information is spatially related.
 Spatial information allow
representation on placed on a map.
 There are different tools that allow
dealing with spatial information.
17

GIS as Information System
 GIS is an information system
specializing in the input, storage,
manipulation, analysis and
reporting of spatially related
information.
18

Main Functions of a GIS
GIS as database applications where:
 All information in a GIS is linked to a spatial reference.
 Other databases may contain location information (street
addresses, zip codes, etc.).
 GIS database uses geo-references as the primary means
of storing and accessing information.
22

GIS as an important tool that:
 Must serve a purpose.
 Not an end in itself but a mean (process) to achieve this end.
 Should be viewed as a process rather than as software or
hardware.
 For decision-thinking (scenarios) and decision-making
(strategies).
 75% of the time used to be spent at building the spatial
database:
Acquiring data for a new GIS has become much simpler.
23

GIS as an Integrating Technology:
 Evolved by linking a number of discrete technologies:
A whole that is greater than the sum of its parts.
 Integrate geographical data and methods:
Support traditional forms of geographical analysis.
Map overlay analysis.
Thematic mapping.
 Integrate geographical data and methods:
Support traditional forms of geographical analysis.
Map overlay analysis.
Thematic mapping.
 Integrates people, data, hardware and software.
24

Data Integration in GIS Environment
 Roads
 Land Parcels
 Population
 Utilities
 Land Mines
 Hospitals
 Refugee Camps
 Wells
 Sanitation
25

The Overlay Concept
 GIS is concerned in answering the questions
Where is the location
What is the attribute
Why is analytical
 GIS depends largely on the concept of overlay in
representing data of different types. Each data type can
be represented in a separate layer and overlaid in a
modern GIS.
27

The Overlay Concept
 With the overlay concept any type of information can be
depicted in a separate layer. Also, two layers or more
can be retrieved on one.
 This provides high degree of freedom to the analysis
processes which enables investigations of different items
separately and also, discover the relationships between
any two or more factors.
28

The Overlay Concept
 Each layer contains features
with similar attributes, like
streets and land parcels, that
are located in the same
geographic extent.
 This simple, but powerful and
versatile, concept has proven
invaluable for solving real-
world problems.
29

The Overlay Concept
Examples
30

The Overlay Concept
Examples
31

GIS Data Model Implementation
 Data is organized by layers, coverages or themes (synonymous
concepts), with each layer representing a common feature.
 Layers are integrated using explicit location on the earth’s
surface, thus geographic location is the organizing principal.
32

GIS Data Types
Graphic (Spatial) data:
 Graphic data is data that can be shown symbolically on
maps or pictorially of photographs. It represents natural
and cultural features whose sizes, shapes and locations
are known.
 These features are represented in a GIS environment in a
digitized form using combinations of fundamental
elements. The standard fundamental elements includes
points, lines and strings, areas and polygons, pixels and
grid cells.
33

GIS Data Types
Non-Graphic (Non-spatial) data:
 Used to describe the characteristics, qualities or relative
special relationships of features or geographic regions.
 Non-graphic data are usually derived from non graphic
sources such as files, tables and documents. They also
stored in separate computer files. There are two types of
non-graphic data used, the attributes and the relative
spatial relationships.
34

Water Resources Engineering
 Water resources engineering is concerned with the
analysis and design of systems to manage the quantity,
quality, timing, and distribution of water to meet the
needs of human societies and the natural environment.
 Water resources are of critical importance to society
because these systems sustain our livelihood and the
ecosystems on which we depend. However, there may be
too little or too much water; and what there is may not
be located where we need it, or it may be too polluted or
too expensive.
36

 All of these factors emphasize the need for wise
development and management of our water resources.
Facilities for water supply and wastewater disposal,
collection and control of flood runoff, and maintenance of
habitat are examples of the relevant applications of water
resources engineering.
 Water resources infrastructure development occurs as a
long process involving information gathering and
interpretation, plan development, decision making and
financing, construction, and operation.
37

 The below schematic diagram illustrates the process of setting
objectives, data collection and synthesis, planning and design,
gathering of information for decision making, and taking action.
It begins and ends with the real world, a world that is
inherently spatial.
38

Domains of GIS in Water Engineering
40

Domains of GIS in Water Engineering
A spectrum of domains for the application of GIS to water
resources engineering are includes:
 Surface water hydrology
 Groundwater hydrology
 Water supply for irrigation
 Wastewater and storm water
 Floodplains
 Water quality
 Monitoring and warning
 River basins
41

Applications of GIS in Water Engineering
 GIS provides an integrating data and modeling
environment for the conduct of these activities. A GIS
provides a means to collect and archive data on the
environment.
 Measurements of location, distance, and flow by various
devices are typically handled in digital formats and
quickly integrated into a spatial database.
 Data processing, synthesis, and modeling activities can
draw on these data using the GIS, and analysis results can
be archived as well.
42

Applications of GIS in Water Engineering
 The GIS spatial and attribute database can then be used
to generate reports and maps, often interactively, to
support decision making on which design alternatives are
best and the impacts of these.
 Further, maps are a powerful communication medium;
thus this information can be presented in public forums so
that citizens concerned with planning and design choices
can better understand and be more involved.
43

 Flood hazard mapping is an exercise to define those
coastal areas which are at risk of flooding under extreme
conditions. As such, its primary objective is to reduce the
impact of coastal flooding.
45

 However, mapping of erosion
risk areas may serve to achieve
erosion risk reduction. It acts as
an information system to
enhance our understanding and
awareness of coastal risk.
46

 Flood hazard assessment and mapping is used to identify
areas at risk of flooding, and consequently to improve
flood risk management and disaster preparedness.
 Flood hazard assessments and maps typically look at the
expected extent and depth of flooding in a given location,
based on various scenarios (e.g. 100-year events, 50-year
events, etc.).
47

 Flood hazard maps can be used by developers to
determine if an area is at risk of flooding, and by insurers
to determine flood insurance premiums in areas where
flood insurance exists.
48

GIS Flood Analysis
 Geographic Information Systems (GIS) are successfully
used to visualize the extent of flooding and also to
analyze the flood maps to produce flood damage
estimation maps and flood risk map.
 The GIS must be used together with a hydraulic method to
estimate flood profile with a given return period.
50

About Paper
 © 2019 The Authors. Published by Elsevier B.V. on behalf of Faculty of
Engineering, Alexandria University.
52

Abstract
 The geomorphological characteristics of the basin are
more commonly used for flood hazard mapping of the
watersheds suffering from scarcity of data.
 In this study, Geographic Information System (GIS)
techniques have been used to carry out the morphometric
analysis of Wadi Qena watershed. The morphometric
parameters considered for analysis are Drainage intensity
(Di), Form factor ratio (FFR) and Circularity ratio (Rc).
53

 Each parameter has been categorized into five grades
ranking from 1 for the lowest hazard grade to 5 for the
highest hazard grade.
 The analysis shows that with respect to the values of Di,
FFR, and Rc, the highest three hazard degree areas
covered about 24.2%, 56.9%, and 46.82% of the total area
respectively. Consecutively, the number of sub-basins
which are classified at the highest three hazard degrees
equals 6, 32 and 38 sub-basins.
Abstract
54

 The overall assessment map indicates that the sub-basins
with hazard degree from moderate to high are equal 34
sub-basins with total area equals 9779.04 km2 (about
63.14% of the total area of Wadi Qena watershed).
 The final developed flood hazard map can initiate
appropriate measures to mitigate the flood hazards in the
area and helps for watershed management.
Abstract
55

 Floods often happen in arid areas as a result of heavy
rains, which sometimes cause significant loss of life and
infrastructure.
 Flood hazard mapping is needed to appropriate land use
and development in flooded areas where the created
maps mitigate their effect.
 Also, flood hazard mapping is very necessary for
managements of water resources and the sustainable
development of watershed in addition to the protection
from the flood hazard and drought.
1. Introduction
56

 The study area is located at the eastern side of Qena
meander in the Upper Egypt. Wadi Qena is located
between Red Sea in the east and River Nile in the
west (Fig. 1).
2. Study Area Description
57

 The area of Wadi Qena watershed is approximately 15455
km2. Based on Koppen climate classification, the climate
of the study area is classified as hot summers and cold
winters as it is located in the dry desert.
 According to Egyptian meteorological Authority (EMA), the
rainfall in the study area is scarce with an average value
of 3.2 mm a year and in summers the highest recorded
temperature reached to 41o in July.
59

 The climatic data for Wadi Qena drainage basin are
traditionally acquired from the closest weather station
which is located at 26o30’N and 33o06’E in the south of
the watershed.
60

 The mountainous area which located in the eastern
boundary is varies in elevation by ranges from 77 m to
1866 m Above the Mean Sea Level (AMSL) (Fig. 2).
61

 The present study deals with the available data that are
useful in order to do the work about the area such as Digital
elevation model (DEM).
 DEM is a digital representation of the topographic surface. It
is used for analysis of topography, modelling of surface
processes, as well as providing flood risk zone.
3. Materials and Methodology
3.1 Digital elevation model (DEM)
63

 The DEM is essential for evaluation both hydrologic
parameters such as, flow direction, flow accumulation,
watershed delineation, drainage networks, and flow length as
well as topographic parameters for example slopes, slope
length and shape and aspects.
64

 The United States Geological Survey website
(www.usgs.gov) offers the Shuttle Radar Topography
Mission (SRTM) data which is required to extract and
generate The DEM of Wadi Qena drainage basin (Fig. 3).
65

66

 To carry out these analyses, the digital elevation model
(90 m resolution DEM) has been used to extract the
drainage network.
 The watershed basin of the study area has been created
by utilizing terrain pre-processing. This pre-processing
used the digital elevation model (DEM) of Wadi Qena
watershed.
3.2 Methodology
67

 The flow accumulation could be created to get the
watershed basin (Fig. 4).
3.2 Methodology
68

 The post-processing involved using the DEM in a GIS
environment for estimation the morphometric parameters:
(stream order (u), area (A), stream number (Nu), stream length
(Lu), drainage density (D), stream frequency (F), Drainage
intensity (Di), Form factor ratio (FFR) and Circularity ratio (Rc)).
 Stream ordering is the major parameter of qualitative and
quantitative analyses of any drainage basin.
 Drainage density (D) is the ratio between the total distance
where the streams run in the sub-basin to total sub-basin
area.
3.2 Methodology
69

 The stream frequency (F) of a drainage basin is the total
number of streams of all orders per square kilometer.
 The drainage intensity (Di) is defined as the proportion of
the stream frequency to the drainage density.
 The form factor ratio (FFR) is defined as the ratio of basin
area to square of the basin length.
3.2 Methodology
70

 The circularity ratio represents the proportion between the
area of the basin and the area of a circle whose
circumference is equal to the basin perimeter.
 To evaluate the flash flood hazard of the study area, a hazard
scale that ranges from 1 (the lowest) to 5 (the highest) is set
for all parameters.
3.2 Methodology
71

The hazard degrees for the sub-basins are distributed as
follows:
 Finding out of the minimum and maximum values of each
morphometric parameter for the sub-basins.
 Calculations of the actual hazard degree for all parameters that
are situated between the minimum and maximum values.
 Assuming a straight linear relation exists between samples points
and intermediate values of hazard degree can be calculated from
the geometric relationship.
3.2 Methodology
72

 For the parameters, have directly proportional relationship:
 For the parameters, have inverse proportional relationship:
3.2 Methodology
73

4. Results and Discussion
4.1 Drainage intensity (Di)
75

4.1 Drainage intensity (Di)
76

4.2 Form factor ratio (FFR)
77

4.2 Form factor ratio (FFR)
78

4.3 Circularity ratio (Rc)
79

4.3 Circularity ratio (Rc)
80

4.4 Overall assessment
 The final flood hazard map was produced by calculation
the summation of the hazard degrees for each sub-basin
(Fig. 13).
81

82

83

84

5. Conclusions
 Flood hazard map was prepared to delineate flood-prone
areas. The results show that based on the values of Di,
FFR, and Rc the numbers of the highest three hazard
degree areas are 6, 32 and 38 sub-basins and covered
about 24.2%, 56.9%, and 46.82% respectively of the total
area of the watershed.
 The overall assessment map indicates that the sub-basins
with hazard degree from moderate to high are equal 34
sub-basins with total area equals 9779.04 km2 (about
63.14% of the total area of Wadi Qena watershed).
85

5. Conclusions
 Most of the hazard areas are located in the southern part
by 25 areas. Such map helps the decision makers to
evaluate the potential impacts of natural risks quickly and
assist further to initiate appropriate measures for impact
reduction.
 The results shown in this research can help the
developers, planners and engineers for effective planning
and developments and to minimize the harmful effects of
flash floods.
86

▸ Geographic Information Systems In Water Resources Engineering, Lynn E.
Johnson
▸ Introduction to Geographical Information System, Dr. Eng. Fahmy F. Asal
▸ GIS Data Model, Data Types and Data Sources, Dr. Eng. Fahmy F. Asal
▸ Flood hazard mapping, Climate Technology Centre & Network
https://www.ctc-n.org/technologies/flood-hazard-mapping
📖References
89

▸ Flood mapping in ArcGIS, GIS Application, Youtube video
https://www.youtube.com/watch?v=1o5wnZTCJl4
▸ GIS Flood Analysis - Esri Canada Higher Education & Research, Youtube video
https://www.youtube.com/watch?v=YqjfdobHBFA
▸ Flood Hazard Mapping by Using Geographic Information System and Hydraulic
Model: Mert River, Samsun, Turkey, Vahdettin Demir and Ozgur Kisi
https://www.hindawi.com/journals/amete/2016/4891015/
▸ Runoff hazard analysis of Wadi Qena Watershed, Egypt based on GIS and
remote sensing approach, Wael M. Elsadek, Mona G. Ibrahim, Wael Elham
Mahmod
📖References
90

THANK YOU 
linkedin.com/in/aGaabdelgawad/

Application of GIS in Flood Hazard Mapping - GIS I Fundamentals - CEI40 - AGA

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Application of GIS in Flood Hazard Mapping - GIS I Fundamentals - CEI40 - AGA

Similar to Application of GIS in Flood Hazard Mapping - GIS I Fundamentals - CEI40 - AGA (20)

More from Ahmed Gamal Abdel Gawad

More from Ahmed Gamal Abdel Gawad (15)

Recently uploaded

Recently uploaded (20)

Application of GIS in Flood Hazard Mapping - GIS I Fundamentals - CEI40 - AGA