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Mr. Ershad Ali | Department of Geography, Ananda Chandra College, Jalpaiguri-735101, India |
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Geographic Information System (GIS): Definition, Development,
Applications & Components
Mr. Ershad Ali
Faculty, Department of Geography
Ananda Chandra College, Jalpaiguri, E-mail: aliershad.geo@gmail.com
A Geographic Information System (GIS) is a system of computer software, hardware and data,
personnel that make it possible to enter, manipulate, analyze, and present data, and the information
that is tied to a location on the earth's surface. This system comprises of Software, Hardware, Data,
and Personnel that make it possible to enter, manipulate, analyze and present information that is tied
to a location on the earth's surface.
Definition of Geographic Information System (GIS)
There are different definitions for Geographic Information System, each developed from a different
perspective or disciplinary origin. Some focus on the map connection, some stress the database or
the software tool kit and others emphasis applications such as decision support. Defining a GIS can be
done by either explaining what it can do (Functions) or by looking at the components. Both are
important to really understand a GIS and use it optimally. An analysis of the three letters of the
acronym GIS gives a clear picture of what GIS is all about:
G: Geographic: Implies an interest in the spatial identity or locality of certain entities on, under
or above the surface of the earth.
I: Information: Implies the need to be informed in order to make decisions. Data or raw facts
are interpreted to create information that is useful for decision-making.
S: System: Implies the need for staff, computer hardware and procedures, which can produce
the information required for decision-making that is data collection, processing, and
presentation.
➢ A GIS is a computer-assisted system for the collection, storage, management, analysis and
representation of geo-referenced data to support decision-making.
➢ A geographic information system (GIS) is a computer-based tool for mapping and analyzing
things that exist and events that happen on earth. GIS technology integrates common
database operations such as query and statistical analysis with the unique visualization and
geographic analysis benefits offered by maps
—
Environmental Systems Research Institute
(Environmental Systems Research Institute- ESRI).
➢ GIS is defined as a computerized system for capture, storage, retrieval, analysis and display
of spatial data describing the land attributes and environmental features for a given
geographic region, by using modem information technology (Thurgood, 1995). According to
this definition, a GIS includes not only computing capability and data, but also managers and
users, the organization in which they function and institutional relationships that govern
their management and use of information.
➢ A GIS can be defined as a computing application capable of creating, storing, manipulating,
visualizing, and analyzing geographic information. It finds its strongest applications in
resources management, utilities management, telecommunications, urban and regional
planning, vehicle routing and parcel delivery, and in all of the sciences that deal with the
surface of the Earth.
➢ Geographic Information System is a system of hardware, software, data, people,
organizations and institutional arrangements for collecting, storing, analyzing and
disseminating information about areas of the earth.
➢ GIS is a system of hardware, software, and procedures designed to support the capture,
management, manipulation, analysis, modeling, and display of spatially referenced data for
Mr. Ershad Ali | Department of Geography, Ananda Chandra College, Jalpaiguri-735101, India |
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solving complex planning and management problems (Rhind, 1989).
➢ GIS is defined as a decision support system involving the integration of spatially referenced
data in a problem-solving environment. (Cowen, 1988)
➢ GIS is defined as a powerful set of tools for collecting, storing, retrieving, at will,
transforming and displaying spatial data from the real world (Burrough, 1986)
➢ GIS is any manual or computer based set of procedures used to store and manipulate
geographically referenced data. (Aronoff, 1989)
➢ GIS is an institutional entity, reflecting an organizational structure that integrates technology
with a database, expertise, and continuing financial support over time (Carter, 1989)
➢ In the strictest sense, a GIS is a computer system capable of assembling, storing, manipulating,
and displaying geographically referenced information, i.e. data identified according to their
locations. Practitioners also regard the total GIS as including operating personnel and the
data that go into the system
(
United States Geological Survey- USGS).
➢ GIS is an integrated system of computer hardware, software, and trained personnel linking
topographic, demographic, utility, facility, image and other resource data that is
geographically referenced (National Aeronautics and space Administration- NASA)
Stages of GIS Development (Evolution of GIS)
Advancements in GIS were the result of several technologies. Databases, computer mapping, remote
sensing, programming, geography, mathematics, computer aided design, and computer science all
played a key role in the development of GIS. We can group the history of GIS into several stages of
development. Each stage in the history of GIS below:
➢ Paper Mapping Analysis with Cholera Clusters: The history of GIS all started in 1854. Cholera
hit the city of London, England. British physician Dr. John Snow began mapping outbreak
locations, roads, property boundaries and water lines. When he added these features to a
map, something interesting happened: He saw that Cholera cases were commonly found along
the water line. Dr. John Snow’s Cholera map was a major event connecting geography and
public health safety. Not only was this the beginning of spatial analysis, it also marked the start
of a whole field of study: Epidemiology – the study of the spread of disease. To this date, Dr.
John Snow is known as the father of epidemiology. The work of John Snow demonstrated that
GIS is a problem-solving tool. He put geographic layers on a paper map and made a life-saving
discovery.
➢ Before 1960 (The GIS Dark Ages of GIS): Dark Ages GIS Computer mapping was in the dark. It
was not developed. All mapping was done on paper or sieve mapping. The technology wasn’t
here for GIS to come to light. In the 1950s, maps were simple. They had their place in vehicle
routing, new development planning and locating points of interest. But none of this was done
on computers. Imagine a world without computer mapping. With all the issues that came with
paper maps, it was no surprise that cartographers and spatial users wanted to explore
computing options for handling geographic data.
➢ 1960 to 1975 (Pioneering time of GIS): in the history of GIS, this was the main incentive to shift
from paper to computer mapping. The early 1960 to 1980s was really the time period of GIS
pioneering. The pieces were coming together with advancements in technology:
o Map graphics as outputs using line printers.
o Advances in data storage with mainframe computers.
o Recording coordinates as data input.
o These initial developments in the world of computing are what propelled GIS its next step
forward. But what GIS really needed was a brilliant mind to put the puzzle pieces together.
o Enter Roger Tomlinson – the father of GIS: It was during Roger Tomlinson’s tenure with the
Mr. Ershad Ali | Department of Geography, Ananda Chandra College, Jalpaiguri-735101, India |
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Canadian government in the 1960s when he initiated, planned and directed the development
of the Canadian Geographic System (CGIS). This was a key time in the history of GIS because
many consider CGIS as the roots of Geographic Information Systems. CGIS was unique because
it adopted a layer approach system to map handling. Because of the vast amount of territory
Canada occupies, the idea for a Canadian Land Inventory was developed in 1964. But it wasn’t
until 1971 that it became fully operational. The Canadian Land Inventory used soil, drainage
and climate characteristics to determine land capability for crop types and forested areas. It
quickly recognized that accurate and relevant data was vital to land planning and decision-
making. Over the years CGIS had been modified and improved to keep pace with technology.
o The United States Census Bureau was early adopters of some of the core principles of GIS. It
was the pioneering work by the US Census Bureau that led to the digital input of the 1970
Census using the data format GBF-DIME (Geographic Base File – Dual Independent Map
Encoding). GBF-DIME became a file format that supported digital data input, error fixing and
even choropleth mapping. Using this format, the US Census Bureau began to digitize Census
boundaries, roads and urban areas. This was a huge step forward in the history of GIS.
o The Ordnance Survey in the UK also started their routine topographic map development. To
this very date, the Ordnance Survey is still producing many different GIS data products
including every house, every fence, and every stream in every single part of Great Britain.
Table: Evolution of GIS
Stage of
Development
The Formative Years
Maturing Technology
GI Infrastructure
Time Frame
1960-1980
1980-Mid-1990
Mid-1990s-present
Technical
environment
Mainframes and
minicomputers.
Proprietary software.
Proprietary data
structure. Mainly raster
based.
Mainframes and
minicomputer.
Geo-relational data
structures. Graphical
users interface. New
data acquisition
technologies like GPS,
Remote sensing
Workstations and PCs.
Network/Internet.
Open system design.
Multimedia. Data
Integration. Enterprise
Computing. Object-
Relational data model.
Major Users
Government,
Universities, Military
Government,
Universities, Military,
Utilities, Business
Government,
Universities and
schools, Military,
Utilities, Business,
General Public
Major
Application
Areas
Land and Resource
Management, Census,
Surveying and
Mapping
Land and Resource
Management, Census,
Surveying and Mapping,
Facilities
Management,
Market
Analysis
Land and Resource
Management, Census,
Surveying and
Mapping, Facilities
Management, Market
Analysis, Utilities,
Geographic Data
Browsing
Source: C.P. Lo Albert, K.W. Yeung, Concepts and Techniques of Geographic Information
Systems; Prentice Hall of lndia
Mr. Ershad Ali | Department of Geography, Ananda Chandra College, Jalpaiguri-735101, India |
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➢ 1975 to 1990 (Commercialization of GIS Software): As governments realized the advantages
of digital mapping, this influenced the work of the Harvard Laboratory Computer Graphics. In
the mid-1970s, Harvard Laboratory Computer Graphics developed the first vector GIS called
ODYSSEY GIS. ESRI’s ARC/INFO used the technical framework from ODYSSEY GIS and this work
led to the next stage of development in GIS – software commercialization.
o In the late 1970s, memory size and graphics capabilities were improving. New computer
cartography products included GIMMS (Geographic Information Making and Management
Systems), MAPICS, SURFACE, GRID, IMGRID, GEOMAP and MAP. In the late 1980s, this
segment of GIS history was marked with an increasing range of GIS software vendors.
o One of these GIS software vendors was Esri – which is now the largest GIS software company in
the world. In 1982, ARC/INFO for minicomputers was launched and in 1986, PC ARC/INFO was
launched with the production of the Intel microcomputer. Esri is now the world’s leading
experts in GIS software development and it has played a key role in the history of GIS.
o At this point in the history of GIS, it also gained steam with some of the first conferences and
published work. The first GIS meeting in the UK were in 1975. It included a small crowd of
academics. The first Esri conference was in 1981 and attracted a crowd of 18 participants. GIS
consultancies started sprouting. Roger Tomlinson first used the term “Geographic Information
System” in his publication in 1968 “A Geographic Information System for Regional Planning”.
That was a real lonely time for GIS.
➢ 1990 to 2010: (User Proliferation): Map Collaboration Users are starting to adopt GIS
technology in different ways. Classrooms, businesses, governments around the world are
starting to harness digital mapping and analysis. All the ingredients were ready for the
infiltration of GIS to the people:
o Cheaper, faster and more powerful computers.
o Multiple software options and data availability.
o The launch of new satellites and integration of remote sensing technology.
o 1990 to 2010 was the period in the history of GIS when it really took off.
o But advancements in the technology have surpassed the average user. GIS users didn’t know
how to take full advantage of GIS technology. Companies were hesitant to adopt GIS software.
Countries didn’t have access to topographical data.
o But over time, these issues were laid to rest. Gradually, the importance of spatial analysis for
decision-making was becoming recognized. Slowly, GIS was being introduced to classrooms
and companies. Software was able to handle both vector and raster data. With more satellites
being launched into orbit, this data collected from space could be consumed in a GIS.
➢ 2010 to Onward (The Open Source Explosion): Open Mapping With users getting accustomed
to GIS software, this has sparked a new revelation in GIS – an open source explosion.
o Amazing projects like QGIS are providing any user with a computer with GIS software.
Processors are now in gigahertz. Graphics cards are crisper than they’ve ever been before. We
now think of GIS data storage in terabytes. It’s no longer megabytes.
o GIS data has become more ubiquitous. TIGER data, Landsat satellite imagery and even LiDAR
data is accessible to download for free.
o Online repositories like ArcGIS Online store massive amounts of spatial data. It’s a matter of
quality control and fitting it for your needs.
o But what stands out is the big shift of GIS users building their own GIS software in an open,
collaborative way. This software is made available to the public and is called open source. The
big plus is: they are for public use at no cost.
o Open source is becoming main stream today. We are gradually entering an era of open source
GIS software. More light is shining on QGIS than ever before. Even though, there will always
Mr. Ershad Ali | Department of Geography, Ananda Chandra College, Jalpaiguri-735101, India |
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be a place for commercial GIS software. Software companies like Esri provide solutions to
practically any spatial problem that exists today.
Applications of Geographic Information System (GIS)
At a broad range of scales, map has become increasingly important as legal document that convey
land ownership and jurisdictional boundaries, as tools to support decision making (For example, in
urban planning). The GIS provides the ability to completely model utility networks, such as those
supplying water, power and telecommunications to a large number of consumers. Such a system
may operate at a variety of scales, modeling service
Connections to consumers, service districts as well as detailed facilities inventories and layouts,
such as transformers, valves conduits, and schematic diagrams. Applications of the GIS are listed
below:
❖ Navigation (Routing and Scheduling): Web-based navigation maps encourage safe navigation
in waterway. Ferry paths and shipping routes are identified for the better routing. ArcGIS
supports safe navigation system and provides accurate topographic and hydrographic data.
Recently DNR, s Coastal Resources Division began the task of locating, documenting, and
cataloging these no historic wrecks with GIS. This division is providing public information that
makes citizens awareness of these vessel locations through web map. The web map will be
regularly updated to keep the boating public informed of these coastal hazards to minimize
risk of collision and injury.
❖ Surveying: Surveying is the measurement of location of objects on the earth’s surfaces. Land
survey is measuring the distance and angles between different points on the earth surface. An
increasing number of national and governments and regional organizations are using GNSS
measurements. GNSS is used for topographic surveys where a centimeter level accuracy is
provided. These data can be incorporated in the GIS system. GIS tools can be used to estimate
area and also, digital maps can prepare.
❖ GIS Applications in Geology: Geologists use GIS in a various applications. The GIS is used to
study geologic features, analyze soils and strata, assess seismic information, and or create
three dimensional (3D) displays of geographic features. GIS can be also used to analyze rock
information characteristics and identifying the best dam site location.
❖ GIS for Planning and Community Development: GIS helps us to better understand our world
so we can meet global challenges. Today GIS technology is advancing rapidly, providing many
new capabilities and innovations in planning. By applying known part of science and GIS to
solve unknown part, that helps to enhance the quality of life and achieve a better future.
Creating and applying GIS tools and knowledge allow us integrating geographic intelligence
into how we think and behave.
❖ Tourism Information System: GIS provides a valuable toolbox of techniques and technologies
of wide applicability to the achievement of sustainable tourism development. They will get all
the information on click, measure distance, find hotels, restaurant and even navigate to their
respective links. Information plays a vital role to tourists in planning their travel from one place
to another, and success of tourism industry. This can bring many advantages for both tourist
and tourism department.
❖ Worldwide Earthquake Information System: One of the most frightening and destructive
phenomena of nature is the occurrence of an earthquake. There is a need to have knowledge
regarding the trends in earthquake occurrence worldwide. A GIS based user interface system
for querying on earthquake catalogue will be of great help to the earthquake engineers and
seismologists in understanding the behavior pattern of earthquake in spatial and temporal
domain.
❖ Energy Use Tracking and Planning: GIS is a valuable tool that helps in the planning organizing
and subsequent growth in the energy and utilities industries. The effective management of
Mr. Ershad Ali | Department of Geography, Ananda Chandra College, Jalpaiguri-735101, India |
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energy systems is a complex challenge. GIS has enormous potential for planning, design and
maintenance of facility. Also it provide improved services and that too cost effectively.
❖ GIS for Fisheries and Ocean Industries: GIS tools add value and the capability to ocean data.
ArcGis is used to determine the spatial data for a fisheries assessment and management
system. It is extensively used in the ocean industry area and we get accurate information
regarding various commercial activities. To enhance minimizing cost for the fishing industry.
Also it can determine the location of illegal fishing operations.
❖ Traffic Density Studies: GIS can effectively use for the management of traffic problems.
Today’s population along with the road traffic is increasing exponentially. The advantage of
GIS makes it an attractive option to be used to face the emerging traffic problems. By creating
an extensive database that has all the traffic information such as speed data, road geometry,
traffic flow and other spatial data and processing this information will provide us the graphical
bigger picture for the traffic management.
❖ Space Utilization: GIS helps managers to organize and spatially visualize space and how it can
best be used. Operational costs can be decreased by more efficiently using space including
managing the moves of personal and assets as well as the storage materials. The 3D
visualization in GIS platforms helps planers to create a feeling of experience like virtual walk
inside the building and rooms before construction.
❖ Development of Public Infrastructure Facilities: GIS has many uses and advantages in the field
of facility management. GIS can be used by facility managers for space management,
visualization and planning, emergency and disaster planning and response. It can be used
throughout the life cycle of a facility from deciding where to build to space planning. Also it
provides facilitate better planning and analysis.
❖ Location Identification: This technique is used to find a location for a new retail outlet. It helps
to find out what exists at a particular location. A location can be described in many ways,
using, for instance, name of place, post code, or geographic reference such as longitude or
latitude or X/Y.
❖ River Crossing Site Selection for Bridges: The important geotechnical consideration is the
stability of slope leading down to and up from the water crossing. It is advisable to collect
historical data on erosion and sedimentation. On the basis of these information asses the
amount of river channel contraction, degree of curvature of river bend, nature of bed and bank
materials including the flood flow and the flow depth, all these can be done in GIS within
estimated time and accurately. This information has been often used for river crossing site
selection for bridges.
❖ Regional Planning: Every day, planners use Geographic Information System (GIS) technology
to research, develop, implement, and monitor the progress of their plans. GIS provides
planners, surveyors, and engineers with the tools they need to design and map their
neighborhoods and cities. Planners have the technical expertise, political savvy, and fiscal
understanding to transform a vision of tomorrow into a strategic action plan for today, and
they use GIS to facilitate the decision-making process. (ESRI, GIS Solutions for Urban and
Regional Planning)
❖ Municipal Infrastructure: Centre-line drawings for streets, water and sewer utilities linked
to databases for integrated planning, construction, and maintenance management.
❖ Regional Planning: Maps, land records, highways, redevelopment plans analyzed for
regional impact.
❖ Tax Management: Property maps, tax records, assessment for tax collection and planning.
❖ Emergency Services: Responding to fire, explosions, hazardous material spills, and other
unpredictable events.
❖ Oil Spill Impacts: Remote sensing and surface based evaluation for tanker spills, war
disasters, and real time management of emergency operations.
Mr. Ershad Ali | Department of Geography, Ananda Chandra College, Jalpaiguri-735101, India |
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❖ Wastewater Management: integrated planning system including sewers, catch basins,
ditches, and waterways for planning storm impacts.
❖ Water Quality Management: Modeling soil, land use, and watershed characteristics to
evaluate alternative scenarios.
❖ Air Emissions: Modeling and display of dispersal and risk from air toxics on regions
surrounding industrial facilities.
❖ Hazard Analysis: Linking drawings and databases to conduct hazardous operations analysis
for chemical operations.
❖ Forestry Management: Imaging and digital elevation modeling to evaluate damage to
forests from the effects of fire, logging, pesticides, and acid rain and to describe trends in
forest resources.
❖ Population Planning: Spatial distribution and mapping overpopulation and slums in
underdeveloped countries using satellite imagery.
❖ Habit Characterization: Analysis of population and migration patterns to support
preservation of endangered species.
❖ Urban Development Planning: Modeling diffusion of development processes to predict real
estate growth patterns.
❖ Government uses: The ability to relate information on activities and resources to a spatial
location and to monitor or predict changes over time is fundamental to modern society. In
this respect, the importance of socio-economic data, such as that produced by national
censuses, cannot be overstressed. International, national, regional and local governments
use GIS for a host of applications from defense and policing activities through regional
planning, strategic studies for renewable energy resources, environmental management
and risk avoidance through urban and rural policy decisions to day-to-day operational
activities such as land registration, property taxation or routing of traffic.
❖ Industrial & Commercial uses: Industry and commerce use GIS in many ways. Utility
companies (power, gas, water, and telephone) are major investors in digital GIS technology
for managing and monitoring their supply networks, often on an international basis.
❖ Business purposes: Businesses use GIS together with other economic information to
determine optimal delivery routes, the location of potential markets or the site of outlets or
factories. Constructors of major infrastructure (roads, railways, and bridges) use GI to
estimate the amounts and costs of material needed.
❖ Agricultural purposes: In sectors such as agriculture, forestry, water resources or mining, GIS
is used to assess yields and management strategies.
❖ Service purposes: In service industries, GIS are used by consultants to advice on how to
improve business efficiency, or to provide services for tourism and transport.
❖ Social purposes: In social investigations, GIS is used to help analyze spatially varying
attributes of the population such as income, crime, health or the quality of housing.
❖ Environmental uses: GIS is used in a wide range of practical environmental issues from
global warming and sea level rise to erosion, flooding and soil, air and water pollution.
Components of G I S
GIS have mainly 5 components: Hardware, Software, Data, People, and Methods.
➢ Hardware: Hardware is the computer on which a GIS operates; GIS software runs on a wide
range of hardware types, from centralized computer server to desktop computers and in
stand-alone or networked configurations. Hardware relates to device used by end users such
as graphic devices or plotters and scanners. Data storage and manipulation is done using a
range of processor. With the development of the Internet and Web based application, Web
servers have become part of much system’s architecture, hence most GIS’s follows 3-Tier
architecture. It consists of the computer system on which the GIS software will run. The choice
Mr. Ershad Ali | Department of Geography, Ananda Chandra College, Jalpaiguri-735101, India |
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of hardware system range from 300MHz Personal Computers to Super Computers having
capability in Tera FLOPS. The computer forms the backbone of the GIS hardware, which gets its
input through the Scanner or a digitizer board. Scanner converts a picture into a digital image
for further processing. The output of scanner can be stored in many formats e.g. TIFF, BMP,
JPG etc. A digitizer board is flat board used for vectorisation of a given map objects. Printers
and plotters are the most common output devices for a GIS hardware setup.
➢ Software: GIS software provides the functions and tools needed to store, analyze and display
geographic information. Key software components are
o Tools for the input and manipulation of geographic information.
o A database management system (DBMS)
o Tools that support geographic query, analysis and visualization.
o A geographical user interface (GUI) for easy access to tools.
o Software is also a highly dynamic part of the system. Dozens of GIS software packages now
exist. These systems are available on many different types of hardware platforms and come
with a wide variety of functional capabilities. GIS software provides the functions and tools
needed to store, analyze, and display geographic information.
o GIS software in use are ArcGIS, MapInfo, Global mapper, AutoCAD Map, etc. The software
available can be said to be application specific. When the low cost GIS work is to be carried out
desktop Global mapper, Mapinfo is the suitable option. It is easy to use and supports many GIS
feature. If the user intends to carry out extensive analysis on GIS including modelling and
report generation, ArcGIS is the preferred option. For the people using AutoCAD and willing to
step into GIS, AutoCAD Map is a good option.
➢ Data: Possibly the most important component of a GIS is the data. Geographic data and related
tabular data can be collected in-house or purchased from a commercial data provider, A GIS
will integrate spatial data with other data resources and can even use a DBMS, used by most
organizations to organize and maintain their data, to mange spatial data. Geographic data are
basically divided into two main groups are vector and raster.
o Vector data/layers in GIS refer to discrete objects represented by points, lines and polygons.
Lines are formed by connecting two or more points and polygons are closed set of Lines.
Layers represent geometries that share a common set of attributes. Objects within a layer
have mutual topology. Vector sources include digitized maps, features extracted from image
surveys and many more.
o Raster data is a continuous grid of cells in two dimensions or the equivalent of cubic cells in
three dimensions. Raster data are divided conceptually into categorical and continuous. In a
categorical raster every cell value is linked to a category in a separate table. Examples Soil
type, vegetation types. Land suitability, and so on. Continuous raster images usually describe
continuous phenomena in space such as Digital Elevation Model where each pixel is an
elevation value.
o Data is one of the most important, and often most expensive, components of a GIS. All data in
a GIS are either spatial data or Attribute data. Spatial data tells us where something occurs.
Attribute data tells what occurs; it tells us the nature or characteristics of the spatial data.
Geographic data, which is comprised of geographic features and their corresponding attribute
information, is entered into a GIS using a technique called digitizing. This process involves
digitally encoding geographic features, such as buildings, roads or county boundaries.
Digitizing is done by tracing the location, path or boundary of geographic features either on a
computer screen using a scanned map in the background, or a paper map that is attached to a
digitizing tablet. The digitizing process can be very tedious and time consuming, especially
when capturing large datasets such as soil polygons, streams or topographic contours.
Mr. Ershad Ali | Department of Geography, Ananda Chandra College, Jalpaiguri-735101, India |
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Fortunately, much of the data GIS users need has been created by government agencies or
commercial operations, and is available for free or for purchase from the data provider or from
a spatial data clearinghouse. GIS uses Relational Databases to store and manipulate attribute
data. A GIS will integrate spatial data with other data resources and can even use a DBMS,
used by most organization to maintain their data, to manage spatial data.
➢ User/People: GIS technology is of limited value without the people who manage the system and
develop plans for applying it to real-world problems. The GIS users range from technical specialists
who design and maintain the system to those who use it to help them perform their everyday
work. The final component required for a true GIS is users. The term "user" may refer to any
individual who will use GIS to support project or program goals, or to an entire organization
that will employ GIS in support of its overall mission. The real power of a GIS comes from the
people who use them. Over the past decade, computers have become much easier for people
to use and more affordable for companies, schools and organizations to purchase. Today GIS is
being used by people, in many different fields, as a tool that enables them to perform their
jobs more effectively. Police use GIS to solve crimes, Emergency 911 operators use GIS to send
emergency personnel to a person in distress. Biologists use GIS to protect plant and animal
species, teachers use GIS to teach lessons in geography, history or engineering. The list of GIS
users in the 21st century goes on and on. Whatever the application, the user is the key to a
successful GIS. GIS users are often envisioned as hands-on computer processing people. While
this is in part true, often a broader spectrum of GIS users is chosen. One classification scheme
(USGS, 1988) classifies users into three groups:
♦ System users ♦ End Users ♦Data Generators
➢ Methods: A successful GIS operates according to a well-designed plan and business rules, which
are the models and operating practices unique to each organization. Geographic Information
System- The organized activity by which people,
o Measure aspects of geographic phenomena and processes.
o Represent these measurements, usually in the form of a computer database, to emphasize
spatial themes, entities and relationships.
o Operate upon these representations to produce more measurements and to discover new
relationships by integrating disparate sources.
o Transform these representations to conform to other frameworks of entities and
relationships.
o These activities reflect the large context (Institution and Cultures) in which these people
carry out their work. GIS is primarily a computer software package for organizing data with
location dimension. However, its capacity to assimilate the concepts and algorithms from
many discipline such as cartography, geography, surveying, statistics, operation research
techniques and computational mathematics make it a versatile tool for handling geo-
referenced data.
It establishes one-to-one correspondence between the spatial and non-spatial
data and thereby performs an integrated analysis. The spatial data could be in
the form of charts,
aerial photos, satellite imageries, plane table surveyed maps
and Global Positioning System (GPS)
generated observation i.e. essentially mapped databases. The non-spatial or the attribute data
could be in the form of
words, numbers and symbols obtained from say census, secondary surveys
and
other sources.
o A successful GIS operates according to a well-designed plan and business rules, which are
the models and operating practices unique to each organization. There are various
techniques used for map creation and further usage for any project. The map creation can
either be automated raster to vector creator or it can be manually vectorised using the,
scanned images. The source of these digital maps can be either map prepared by any survey
agency or satellite imagery.
Mr. Ershad Ali | Department of Geography, Ananda Chandra College, Jalpaiguri-735101, India |
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Benefits of Geographical Information Systems
GIS can lead to new ways of thinking about and dealing with old problems, because the data is tied
to a common referencing system, it is easy to use the same data to various applications as well as to
associate diverse data sets previously unavailable for joint analysis. Topology permits new questions to
be asked and encourages a n e w style of analysis that is in many cases fundamentally better
than those used traditionally.
GIS provides the following benefits:
Better decision making: This typically has to do with making better decisions about location.
Common examples include real estate site selection, route/corridor selection, zoning, planning,
conservation, natural resource extraction, etc. People are beginning to realize that making the
correct decision about a location is strategic to the success of an organization.
Improved communication: GIS-based maps and visualizations greatly assist in understanding
situations and storytelling. They are a new language that improves communication between
different teams, departments, disciplines, professional fields, organizations, and the public.
Better geographic information recordkeeping: Many organizations have a primary
responsibility of maintaining authoritative records about the status and change of geography
(geographic accounting). Cultural geography examples are zoning, population census, land
ownership, and administrative boundaries. Physical geography examples include forest
inventories, biological inventories, environmental measurements, water flows, and a whole
host of geographic accountings. GIS provides a strong framework for managing these types of
systems with full transaction support and reporting tools.
Managing geographically: In government and many large corporations, GIS is becoming
essential to understand what is going on. Senior administrators and executives at the highest
levels of government use GIS information products to communicate. These products provide a
visual framework for conceptualizing, understanding, and prescribing action. Examples
include briefings about various geographic patterns and relationships including land use,
crime, the environment, and defense/security situations.
It adds a degree of intelligence and sophistication to a transport database that has
previously been unknown.
It is possible to perform, geographic queries in a straight forward, intuitive fashion.
The analyst can ask a series of geo-based questions and obtain the answers quickly in an easy
to understand colour-coded display on the screen, hard copy or disk file.
Integrates different databases into one environment. Each layer in a GIS database may
represent a complete database (One layer may
contain census geographic with associated
demographic information.
Displays and manages spatial data in a spatial context. Often, spatial data are managed in
tabular database that do not allow viewing or management of the data with spatial tools.
Predictions of specialized maps and graphic products.
Redundancy and other problems of multiple map sets are eliminated.
Map data is easier to search, analyze and present.
Cost savings resulting from greater efficiency. These are associated either with carrying out
the mission (i.e., labor savings from automating or improving a workflow) or improvements in
the mission itself.
Functions of Geographic Information Systems
The processes of integration and interrogation can be broken down into a number of general
categories. Laurini and Thompson have identified ten major tasks for spatial information systems:
Automated Mapping: Replicating paper maps on computers.
Thematic Mapping: For instances using customer information and demographic data.
Map Overlay or Composite Mapping: Producing a map from several layer of data.
Mr. Ershad Ali | Department of Geography, Ananda Chandra College, Jalpaiguri-735101, India |
11
Spatial Querying: Obtaining information from a database in response to identification of
particular conditions.
Spatial Browsing: Exploring the contents of a database in response to identification of
particular conditions.
Spatial Problem Solving: For example deducing inclusions of points in polygons, or for spatial
decision-making incorporating both spatial and logical deductive reasoning.
Analysis of Spatial Data: Tasks which deal with the attributes of entities, like the average
size of sales territories or the degree to which product sales are related to weather
conditions.
Creating Spatial Statistics: Tasks that require measurements of spatial properties of
phenomena, like the total distance traveled by a vehicle on a road of Jalpaiguri.
Analysis of Spatial Statistics: Tasks which treat spatial properties as attributes, for example
the correlation between the highway network connectivity and levels of economic
development.
Spatial Analysis: Encompassing tasks, including simulation, which use a variety of tools of
spatial statistics and location-based problem solving.
➢ A Classification of GIS Functions
Data Pre-processing and Manipulation
o Data validation and editing, e.g. checking and correction.
o Structure conversion, e.g. conversion from vector to raster.
o Geometric conversion, e.g. map registration, scale changes, projection changes, map
transformations, rotation.
o Generalization and classification, e.g. reclassifying data, aggregation or disaggregation, co-
ordinate thinning.
o Integration, e.g. overlaying, combining map layers or edge matching.
o Map enhancement, e.g. image enhancement, add title, scale, key, and map symbolism,
draping overlays.
o Interpolation, e.g. kriging, spline functions, Thiessen polygons, plus centroid determination
and extrapolation.
o Buffer generation, e.g. calculating and defining corridors.
o Data searching and retrieval, e.g. on points, lines or areas, on user defined themes or by using
Boolean logic. Also browsing, querying and windowing.
Data Analysis
o Spatial analysis, e.g. connectivity, proximity, contiguity, intervisibility, digital terrain modelling.
o Statistical analysis, e.g. histograms, correlation, measures of dispersion, frequency analysis.
o Measurement, e.g. line length, area and volume calculations, distance and directions.
Data Display
o Graphical display, e.g. maps and graphs with symbols, labels or annotations.
o Textual display, e.g. reports, tables.
Database Management
o Support and monitoring of multi-user access to the database.
o Coping with systems failure.
o Communication linkages with other systems.
o Editing and up-dating of databases.
o Organizing the database for efficient storage and retrieval.
o Maintenance of database security and integrity.
o Provision of a “data independent” view of the database.
Mr. Ershad Ali | Department of Geography, Ananda Chandra College, Jalpaiguri-735101, India |
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References:
1.
C.P.Lo. Albert. & W. Yeung (2002): Concepts and Techniques of Geographic Information
Systems, PHI, pp 87.
2.
Dobson, J.E. Commentary (1993): A Conceptual Framework for Integrating Remote
Sensing, GIS, and Geography, Photogrammetric Engineering and Remote Sensing, Vol. 59,
No. 10, October 1993, pp 1491-1496.
3.
French, G.T (1996): An Introduction to the Global Positioning System- What it is and how it
works, Geo Research INC, Bethesda, pp 189.
4.
Jordon, L.E, & J. GIM (1993): Interviews the GIS Industry, Geodential Information
Magazine, Vol. 7, No. 10, October 1993, pp 35-39.
5.
Joseph, G & Jeganathan, C (2018): Fundamentals of Remote Sensing, Universities Press
Private Limited, Hyderabad, pp456-469.
6.
Lemmens, M (2011): Geo-information – Technologies, Applications and the Environment,
Delft University of Technology, The Netherlands, pp 85-99.
7.
Peterson, G.N (2009): GIS Cartography- a Guide to Effective Map design, CRC Press, Taylor
& Francis Group, 224P.
8.
Sarkar, A (2019): Practical Geography- A systematic Approach, Orient Blackswan Private
Limited, Hyderabad, pp 395-415.
9.
Thurgood, I.D and J.S Bethel: Geographic Information Systems, Civil Engineering
Handbook, CRC Press, Indiana.
10.
Tor, Bernhardsen: Geographic Information Systems, an Introduction, John Wiley and Sons
Inc.
11.
Weng, Q (2010): Remote Sensing and GIS Integration, Mc Graw Hill Publication, New York,
pp 8-78.
12.
Wing, M.G & Bettinger, P (2008): Geographic Information Systems- Application in Natural
Resource Management, Oxford University Press, New York, pp 2-24.
13.
Geographic Information Systems Challenges to Effective Data Sharing Statement of Linda
D. Koontz Director, Information Management Issues viewed at www.gao.gov/cgi-
bin/getrpt? GAO-03-874T. (accessed on 12th March, 2020)
14.
GIS and Science- Application for Geospatial Technology for Scientific Research and
Understanding viewed at https://gisandscience.com/2009/09/14/top-five-benefits-of-gis/
(accessed on 21th March, 2020)
15.
GIS Applications viewed at https://grindgis.com/blog/gis-applications-uses (accessed on
16th March, 2020)
16.
GIS Geography viewed at https://gisgeography.com/history-of-gis/ (accessed on 12th
February, 2020)
17.
Overview of Geographic Information Systems (GIS) viewed at
https://shodhganga.inflibnet.ac.in/bitstream/10603/108205/12/12_chapter%204.pdf
(accessed on 20 March, 2020)
18.
The Function of a GIS viewed at http://www.fao.org/3/W0615E/W0615E06.htm (accessed
on 20th March, 2020)
