Basics of Geographic Information Systems (GIS) - Lecture One

Introduction to Geographic Information Systems (GIS)

Geographic Information Systems, commonly known by the acronym GIS, is an integrated computer-based system used for collecting, storing, processing, analyzing, managing, and displaying data linked to a specific location. Information is presented in the form of maps or models that facilitate the understanding of spatial phenomena and relationships to support decision-making. In its simplest sense, GIS represents information combined with geographical location; any piece of information that can be pinpointed on the Earth's surface can be entered and analyzed within these systems.

A comprehensive definition of GIS is a computer system consisting of hardware, software, data, and individuals. It aims to enter, store, manage, analyze, and display both geographical and descriptive spatial data. This structure helps in understanding patterns, relationships, and procedures, ultimately supporting the decision-making process.

Analytical Capabilities and Spatial Questions

GIS helps in answering a wide variety of questions related to identification, conditions, locations, measurements, changes, and pattern distribution. Specific examples of these questions include:

• Identification: Determining the agricultural pattern in a specific area or identifying the types of crops suitable for cultivation in a particular unit.
• Conditions: Identifying specific infrastructure, such as the diameter of an irrigation pipe required to irrigate a specific unit, or locating all irrigation pipes with a diameter of $300\,mm$ within a certain region.
• Location: Pinpointing where specific measurements or features are located.
• Measurements: Calculating the area and coordinates of specific units.
• Change: Tracking temporal changes, such as the degree of soil salinity from the year $1965$ to the year $2006$.
• Pattern Distribution: Analyzing the relationship between population distribution and the locations of water sources.

Historical Evolution of GIS

The origins of spatial analysis date back to $1854$, when John Snow mapped the cholera outbreak in London using dots to represent the locations of individual cases. His study of cholera distribution led to the discovery of the epidemic's source (the Broad Street pump). In $1958$, a similar version of Snow’s map appeared, showing clusters of epidemic cases.

During the early $20th$ century, significant developments occurred in cartography with the separation of maps into layers. Nuclear research in the mid-$20th$ century accelerated computer hardware development, leading to the creation of general computer-based mapping applications by $1960$. In $1962$, the first actual GIS was developed in Ottawa, Ontario, Canada. By $1967$, the system was used for land management and natural resource management in New York State, followed by the Minnesota Land Management Information System in $1969$.

In these early stages, GIS projects were extremely expensive, making them accessible only to large regional and state departments in the United States. During this period, the Urban and Regional Information Systems Association (URISA) was established. The Canada Geographic Information System (CGIS) became the first practical geographic information system, producing land scales of $1:50,000$. This sparked further development across the United States, Canada, Australia, Britain, and other developed European nations.

The Information Revolution and Modern GIS

By the early $1980s$, many successful GIS programs emerged with additional features that combined the strengths of the first and second generations of technology. This era was characterized by an expanding user base and the development of direct communication between GIS pioneers and users through global and specialized networks. Scientific journals, symposia, conferences, and specialized courses began to proliferate. The rapid development of storage hardware, input and output devices, and specialized software during the $1980s$ led to this period being dubbed the beginning of the information revolution in GIS, marked by high-speed data processing and versatile functional capabilities.

In the $1990s$, the interest in teaching GIS in universities and scientific institutes grew significantly. Hardware and software capabilities increased alongside the emergence of the Global Positioning System (GPS). The availability of satellite imagery at affordable prices provided abundant information about the Earth's surface. Entering the $21st$ century, satellite sensors evolved to provide detailed information with excellent accuracy and high speed. By the end of the $20th$ century, GIS data could be displayed over the internet due to the commitment to new transfer standards, formats, and the spread of open-source software. Today, GIS continues to evolve as a branch of science that grows in importance as access to information becomes easier.

Distinction Between GIS and GPS

There is often confusion between Geographic Information Systems (GIS) and the Global Positioning System (GPS) due to the similarity of the terms. GPS is primarily a source of spatial data, providing coordinates such as latitude, longitude, and time. In contrast, GIS is a computer program or application that performs more complex analytical tasks. GIS acts as a system for processing, analyzing, and storing data in massive databases. While GIS may derive its primary data from other systems like GPS, its analytical power depends on the accuracy of the inputs received from those external systems.

Features and Advantages of GIS

GIS offers several technical and administrative features:

• Project Planning: Aids in planning new projects and expansions.
• Efficiency: Provides rapid access to large volumes of information with high effectiveness.
• Decision Support: Facilitates making the best possible decisions in the shortest time.
• Information Dissemination: Helps publish information to a larger number of beneficiaries.
• Data Integration: Merges spatial information and descriptive information into a single database.
• Standardization: Documents and confirms data and information according to unified specifications.
• Coordination: Ensures coordination between relevant authorities and information sources before decision-making.
• Analytical Power: Offers high spatial analytical capabilities and the ability to answer complex queries regarding locations or descriptive data.
• Visual Representation: Provides the ability to visually represent spatial information.
• Simulation: Allows for the simulation of new proposals and planning projects to study results before actual implementation on the ground.

Economic and Practical Benefits

The implementation of GIS leads to significant improvements in efficiency:

• Reduction in Map Production Time: Historically, creating a single map could take many days or even a full month to draw lines, define terrain, and name places. With GIS, map preparation takes only a few hours.
• Labor Reduction: Map-making departments previously required large numbers of employees. Technological development and GIS have automated tasks like drawing, preparation, and coloring, leading to a reduction in the necessary workforce.
• Cost Reduction: While initial setup costs for GIS might be high, it reduces long-term financial expenditure by eliminating the need for recurring costs like map paper, specialized pens, and colors. These savings are realized because the core system is paid for once.

Diverse Applications of GIS

GIS is utilized across a wide range of fields due to its database search and inquiry capabilities:

• Crisis Management: It allows for the analysis of road networks and infrastructure to determine the shortest and most appropriate paths between points. This is vital for managing spatial disasters such as floods, earthquakes, fires, hurricanes, and the spread of epidemics.
• Emergency Medical Services: It provides data on accident types and demographics to speed up the response of emergency services. By identifying the nearest ambulance unit and alternative routes, it optimizes rescue efforts and can track the spread of infectious diseases.
• Urban Planning: It identifies underserved areas to redistribute services, compares planned designs with reality to determine legal ownership, and builds mathematical models for informal settlements to limit their spread.
• Environmental Protection: By comparing images and maps from different dates, GIS tracks physical, biological, chemical, and climatic changes in specific environments and estimates the impact on neighboring areas.
• Economic and Social Studies: Experts use GIS to analyze socio-economic characteristics and derive development indicators to support decisions in all development directions.
• Terrain Analysis: GIS provides accurate visualizations of the Earth's surface through contour maps. It can calculate quantities for excavation and filling (cut and fill) and determine the directions of torrents and slopes.
• Productivity Enhancement: It facilitates communication between different departments. By building a unified database, data collected once can be used multiple times across different sections, increasing the overall efficiency of an organization.
• Decision Support Systems: It identifies the most suitable locations based on user-defined criteria, such as distance from main roads, price per meter, and proximity to pollution. It is an inquiry tool that provides clear and accurate information to the decision-maker.
• Map Construction: GIS is more flexible than manual methods. It involves building databases, digitizing paper maps, and updating them with satellite imagery to represent specific features like archaeological sites or farms using defined symbols.

Categories of GIS Applications

GIS applications are categorized according to the sector they serve:

Government Applications

• Topographic maps.
• Network representation models (land, sea, and air routes).
• Environmental assessment.
• Global navigation systems.
• Mining and exploration.
• Thematic maps.
• Water resources (discovery, planning, and management).
• Ships and aircraft applications.
• Production, updating, and publishing of base maps.
• Tax maps (geographical distribution of taxpayers).

Service and Private Sector Applications

• Electricity and power grid applications.
• Petroleum fuel distribution.
• Water networks.
• Sewage and sanitation applications.
• Telecommunications and phone services.
• Forestry applications.
• Transportation applications.
• Private industrial applications in petroleum and marketing.
• Real estate development and planning charts.