GIS (Geographic Information System) technology, what is it and what’s it for?

When we use an app or visit a website with information shown on a map, for example our navigation system, or simply search for a restaurant in a certain area, we are using a simple technology based on a century old idea: GIS.

In this article, we will delve into the topic of GIS and how BIM-GIS software is useful in this field.

What is a GIS and how does it work

A GIS (Geographic Information System) is an advanced computer tool that allows for the acquisition, storage, management, analysis, and visualization of geospatial data, which refers to information associated with a specific location on the Earth’s surface. Essentially, a GIS links descriptive data (attributes) to geographic coordinates, thus enabling the representation and understanding of spatial phenomena through interactive digital maps.

It is, therefore, a set of computer/geographic systems primarily designed for:

• land management,
• urban and infrastructure planning,
• the study of territorial transformations over time,
• the creation of Civil Protection plans,
• the creation of thematic maps (hydrographic, seismic, demographic, traffic, etc.),
• statistics, demographics,
• the study of archaeological-cultural/environmental/building heritage,
• GPS applications.

Spatial data can be vector (points, lines, and polygons representing geographic objects) or raster (pixel grids, such as satellite images), and are stored in relational databases that facilitate management and analysis.

Through GIS, it is possible to perform complex operations such as spatial queries, network analysis, buffer analysis, and overlay of thematic layers, to identify relationships between geographic elements, recurring patterns, and territorial contexts that would otherwise be difficult to grasp. The results are displayed in the form of digital maps, graphs, or interactive reports, providing powerful tools for urban planning, environmental management, transportation, geomarketing, public health, and many other fields.

In summary, GIS transforms large amounts of raw geographic data into useful and actionable knowledge to support location-based decisions.

GPS systems are based on GIS technology

GIS, its historical background

To fully understand what GIS is, let’s put what we know today aside for one moment. Its origin goes back to 1854, when in London’s Soho district a deadly epidemic struck the population.

A doctor named John Snow, began a study where he identified and localized contagious cases on a map of London, connecting the geographic distribution with the number of people infected.

Monitoring the course of the outbreak throughout time, Dr. Snow understood that certain areas represented the source of the disease.: that’s when the idea of geo-referencing a determined characteristic was born, therefore coming to a conclusion on how to operate. This is one of the first real applications of GIS.

Historical maps of the London district of Soho

By definition, GIS is a system that puts geographic information in relation with other information contained in a database system (demographic, environmental, urbanistic, etc..).

One of the first definitions of GIS in the digital era was introduced in 1986 by Peter A. Burrough, professor at Oxford University (UK):

“GIS consists in a series of software instruments made to acquire, store, extract, elaborate and visualize spatial data in the real world”

Core Components of a Geographic Information System

GIS is integrated in software that connects typical database operations to geographically oriented analysis, connecting alphanumerical information to spatial information, obtaining precise georeferenced data.

Geographic information (maps, photos, etc..) play an important role in the decisional process, being easily and immediately comprehensible, even to non-technical people.

Fundamental components

GIS is much more than just software: it is a complex and integrated system composed of five fundamental components that work together to collect, manage, analyze, and visualize geospatial data.

• hardware – includes all the physical devices necessary for the operation of GIS, such as computers, servers, GPS, scanners, printers, and even drones. These tools support processing, field data collection, and the production of high-quality cartographic outputs;
• software – constitutes the operational heart of GIS. It includes applications that allow for the processing of spatial data, creating maps, conducting analyses, and visualizing results. They often integrate with database management systems (DBMS) to organize data efficiently;
• data – represent the informational content of the system. They are divided into spatial data, which describe the location and shape of geographic objects (in vector or raster format), and attribute data, which contain descriptive information about the represented elements (e.g., street name, building height);
• methods – include all the procedures, techniques, and practices necessary to correctly use a GIS. From data collection to analysis, to the generation of maps and reports, methods define the workflow and ensure consistency and accuracy in results;
• people – are the users who operate the system, manage it, and interpret the information produced. This includes GIS analysts, technicians, planners, decision-makers, and anyone who uses geospatial data to support strategies and decisions in areas such as urban planning, environment, transportation, and civil protection.

The synergy between these elements allows GIS to transform large volumes of raw geographic data into useful and visually effective information, making it an essential tool for planning, analysis, and land management.

Types of data in GIS systems

In GIS, data can be classified based on format, content, and representation mode, according to three main distinctions: digital and analog data, spatial and non-spatial data, and thematic maps and informational layers.

Digital and analog data

Analog data represent territorial information in physical format, such as paper maps, aerial photographs on film, or textual documentation. To be used in a GIS environment, these must be converted to digital format through scanning, georeferencing, or manual digitization processes. In contrast, digital data are natively in electronic format and immediately readable by a computer. They include vector and raster data from GPS sensors, satellite images, alphanumeric databases, or computer-generated maps. These data are ideal for processing, storage, and analysis in GIS software. In this regard, there are GIS-geospatial solutions available on the market, which differ from other information systems as they offer endless possibilities for use related to geographic components.

Spatial vs non-spatial data

Spatial data (or geographic) represent objects with a precise location on the Earth’s surface, through coordinates. They can be modeled with vector geometries (points, lines, and polygons) or in raster format (cell grids), and allow answering the question “where is something located?”. Non-spatial data (or attributes) provide descriptive information about spatial objects, such as names, dates, physical characteristics, land use, or statistical values. Organized in tables linked to geographic objects through unique identifiers, they enrich spatial analyses and support more informed decisions.

Thematic maps and informational layers

In a GIS, information is represented through thematic maps and informational layers. Thematic maps are maps focused on a specific phenomenon – for example, population density, agricultural land use, or hydrogeological risk – and derive from the combination of spatial data and attributes, with the application of ad hoc symbology. Informational layers, on the other hand, are the various digital layers on which different categories of geographic data are organized and stratified. Each layer can represent a specific type of entity (roads, buildings, rivers, administrative boundaries) and can be analyzed individually or in combination with others. The multi-layer management of layers allows for powerful, flexible spatial analysis focused on the user’s objectives.

To further explore the topic, I recommend reading the article “Spatial data analysis in GIS“.

GIS LAYERS based system

The operational phases of a GIS project

The development of a GIS project follows a structured cycle that allows for the transformation of raw data into useful geographic information for decision support. This process is divided into three main operational phases: data acquisition and updating, territorial modeling and simulation, and visualization, analysis, and representation. These phases are interconnected and often iterative, ensuring dynamic and coherent management of spatial information.

Data acquisition and updating

The first phase consists of the collection and preparation of geographic data, which can come from multiple sources: GPS surveys, remote sensing, aerial photographs, digital maps, censuses, existing databases, or field surveys. This is followed by a crucial phase of preparation and cleaning, which includes georeferencing, transformation into consistent coordinate systems, and data validation to correct errors or inconsistencies. The continuous updating of information is essential, as it allows the GIS system to remain aligned with the transformations of the territory and the phenomena analyzed.

Territorial modeling and simulation

After acquiring and organizing the data, the next step is modeling, which is the structured representation of the geographic reality in conceptual, physical, and logical models. This phase allows for defining spatial relationships between objects (topology) and structuring data efficiently within geospatial databases. Territorial simulation then allows for predicting alternative scenarios and analyzing complex phenomena, such as urban expansion, risk management, infrastructure planning, or environmental impact. Through advanced GIS tools, it is possible to conduct suitability analyses, simulate flows, and evaluate strategic options for territorial development.

Visualization, analysis, and representation

The final phase involves the transformation of data into understandable and communicable information. This occurs through thematic maps, informational layers, three-dimensional models, dashboards, and interactive reports. Spatial analysis techniques, such as geographic queries, proximity analysis, overlay, geostatistics, and network analysis, allow for answering specific questions and identifying hidden patterns in the data. Cartographic representation, finally, is a fundamental tool for communicating results clearly and effectively supporting decision-making processes, also thanks to the use of webGIS and applications accessible in real-time.

The levels of complexity of a GIS

In general, three main levels of use are identified, reflecting a growing evolution of available functionalities and analytical capacity.

• Level 1 – GIS as a basic visualization and querying tool. In this initial phase, the system operates on a single informational layer and allows for simple operations such as visualization, distance or area calculations, attribute identification, and execution of basic queries. It is the typical level for those using GIS as a thematic archive, useful, for example, for consulting a map of a road network or verifying the location of an infrastructure;
• Level 2 – Multilayer GIS for complex spatial analyses. With the introduction of multiple overlapping layers, GIS becomes a more powerful analytical tool. At this level, advanced spatial analyses such as overlays, buffers, spatial joins, or proximity analyses are performed. This is the case, for example, of an urban planner evaluating the optimal location for a park considering population density, the presence of green areas, and buildable zones;
• Level 3 – GIS as a modeling and decision support platform. The most advanced level involves the use of complex algorithms, simulations, and predictive modeling. Data come from heterogeneous sources and are integrated to simulate scenarios (“what-if”), support strategic decision-making processes, or plan large-scale interventions. In this context, a GIS can be used to predict the impact of a flood, plan optimized transportation networks, or support locational choices through multi-criteria analysis.

These three levels represent a scale of increasing sophistication of GIS, evolving from a simple cartographic consultation tool to an advanced decision-making system. The transition from one level to another is not rigid but gradual and depends on the user’s or organization’s ability to manage and interpret increasingly complex data to gain a deeper understanding of the territory.

What is GIS – Video

Below we propose a short video (in English) that briefly illustrates what GIS is.

FAQ about what GIS is

What is a GIS and what is it used for?

A GIS (Geographic Information System) is a computer system that allows for the acquisition, storage, management, analysis, and visualization of geospatial data, that is, data linked to a geographic location. It is used for applications such as urban planning, environmental management, demographic analysis, and civil protection.

What are the main applications of GIS?

The main applications include land management, urban and infrastructure planning, the study of territorial transformations, civil protection, the creation of thematic maps, statistics and demographics, archaeological and cultural analysis, and GPS applications.

What is the history and origin of GIS?

The origin of GIS dates back to 1854, when Dr. John Snow mapped cholera cases in the London neighborhood of Soho to identify the source of the epidemic. This represents one of the first applications of data georeferencing for spatial analysis.

What are the fundamental components of a GIS system?

The five main components are: hardware (e.g., computers, GPS, drones), software (e.g., GIS software and databases), data (spatial and attributes), methods (procedures and workflows), and people (users, analysts, decision-makers).

What types of data are used in GIS?

Digital and analog data are used, spatial (with geographic coordinates) and non-spatial (descriptive attributes), organized into thematic maps and informational layers. The main formats are vector and raster.

What are the operational phases of a GIS project?

The three main operational phases are: data acquisition and updating, territorial modeling and simulation, visualization and analysis of data with representation through maps, layers, and interactive dashboards.

What are the levels of complexity of using a GIS?

The main levels are three: 1) GIS for simple visualization and queries, 2) multilayer GIS for complex spatial analyses, 3) GIS as a modeling and decision support platform, with simulations and analyses.