What is GIS (Geographic Information Systems)?

17 October 2023


Geographic Information Systems (GIS) is a field that beautifully synthesizes numerous data sources to offer a comprehensive view of our world. From capturing historical records to monitoring real-time events, the wealth of data that pours into GIS is immense and varied.

At its inception, GIS was predominantly a command-line, workstation-based tool. The early days saw professionals interacting with black screens filled with coded commands, meticulously crafting them to extract, analyze, and visualize geographical data. The computing power was limited, the user interfaces were less intuitive, and the entire process required a steep learning curve. Today, with the cloud's introduction and growing ubiquity, GIS applications can now harness vast computational power remotely, negating the need for robust local systems.

Origins of GIS Data

Every GIS dataset begins with a source, and these sources have expanded and diversified over time. Some of these data collection methods:

Field GIS Data Collection: This is the grassroots method. Field workers, equipped with specialized tools and devices, venture out to collect data directly from the source, be it landscapes, urban areas, or specific sites of interest. Such hands-on methods ensure that the data collected is both accurate and relevant.

GPS (Global Positioning System): Revolutionizing spatial data collection, GPS uses satellite-based navigation systems to pinpoint accurate geographical locations. Whether you're marking the boundary of a wildlife reserve or the location of a new cafe, GPS facilitates precise data collection.

LiDAR (Light Detection and Ranging): An advanced remote sensing technology, LiDAR measures distances using laser light. It's invaluable for creating high-resolution maps, particularly for elevations, making it a preferred method for topographic mapping and forestry applications.

Satellite Imagery: Satellites orbiting our Earth continuously capture images of our planet. These images, varying in resolution and spectral bands, are crucial for monitoring land changes, detecting deforestation, or studying urban development.

Aerial Photographs: Taken from aircraft, these photographs provide a bird's-eye view of the landscape. Before the prevalence of satellite imagery, aerial photos were the primary source for large-scale mapping.

Remote Sensing: This is a broad field that involves collecting data from a distance, primarily from satellite or aircraft. It provides insights into environmental changes, land cover, and even oceanic phenomena.

These diverse sources feed data into GIS software platforms like ArcGIS, QGIS, and GRASS GIS. Such platforms act as the cauldron where the raw data is processed, analyzed, and visualized.

GIS Attribute Data

While the term 'GIS' often evokes images of intricate maps and spatial layouts, the soul of GIS lies just as much in its attribute data. But what exactly is this data?

At its core, attribute data provides context to spatial features. Imagine having a map dotted with numerous points representing schools. While the coordinates give you their locations (the spatial data), how do you differentiate one school from another?

For each school (a spatial feature), attribute data offers a wealth of information. The school's name tells you its identity. The level of education (primary, secondary, etc.) offers insights into its academic offerings. The student capacity sheds light on its size. All these 'additional' pieces of information are encapsulated within the attribute data.

Spatial and Attribute Data

When spatial data and attribute data come together, magic happens. It's this partnership that elevates GIS from being just a mapping tool to a potent instrument for analysis and decision-making.

Think about urban planning. The spatial data might show available plots of land. But it's the attribute data – soil quality, ownership details, nearby amenities – that informs planners where to construct a park, a housing complex, or a commercial establishment.

GIS Applications

Geographic Information Systems (GIS) has proven its utility across diverse sectors, showcasing its versatility and expansive scope. At its core, GIS is about understanding our world from a spatial perspective, gleaning insights, and drawing patterns from seemingly unrelated data points.

GIS: Spatial Analysis

Instead of treating data as isolated entities, GIS integrates spatial and attribute data, offering a holistic view of the information landscape. By leveraging both spatial and statistical methodologies, GIS can reveal patterns, anomalies, or relationships that would remain obscured in traditional databases or spreadsheets.

Types of Information Derived from GIS Analysis

Derivative Information: This is the information extracted or derived from primary geospatial datasets. For instance, from a topographic map, one can derive slope or aspect maps.

Interpolated Information: GIS can predict values for regions where data isn’t directly available by using known values from surrounding areas. For example, predicting rainfall in unmonitored areas based on nearby weather stations.

Prioritized Information: GIS can rank or prioritize areas based on specific criteria, such as identifying land suitable for agriculture based on soil quality, water availability, and climate.

These analyses often involve layering various datasets and examining them collectively to answer specific spatial queries. The outputs? Maps that don't just display data but narrate a story, offering insights and solutions.

The Questions GIS Can Answer

To truly appreciate the versatility of GIS, let's explore some real-world questions it helps answer:

Urban Planning and Infrastructure: By conducting a buffer analysis, planners can determine the number of schools within a specific radius of a bus stop. Such insights help in creating efficient transportation routes.

Telecommunication: Through a line-of-sight analysis, companies can pinpoint areas with the strongest cellular signals, guiding tower placement for optimal coverage.

Environmental Studies: Using the NDVI (Normalized Difference Vegetation Index) classification, analysts can classify different vegetation types from satellite imagery, aiding in conservation efforts and land use planning.

Urban Design and Accessibility: A street network analysis can evaluate how walkable a neighborhood is, considering factors like sidewalk availability, road connectivity, and traffic patterns.

Public Safety: Hot spot analysis in GIS can illuminate areas of high crime, enabling law enforcement to allocate resources more effectively and devise strategies for community safety.

Disaster Management: GIS can predict areas most susceptible to natural disasters like hurricanes or cyclones. By studying historical data and current conditions, authorities can prepare and safeguard vulnerable coastal populations.

GIS Jobs

GIS isn't just about technology; it's about the fusion of technology with real-world applications. The myriad job roles associated with GIS are a testament to its expansive reach.

Retail moguls employ GIS to pinpoint the perfect locale for their next outlet. Meanwhile, marketing aficionados use it to tailor their strategies, ensuring their campaigns resonate with the target demographic and locale.

In the scientific community, GIS has become an indispensable ally. Population analysts might delve into GIS to evaluate the correlation between population density and essential resources, while biologists could use it to track the migratory patterns of endangered species.

The arena of disaster management sees city and federal officials turning to GIS to strategize their responses to calamities. In the blink of an eye, a GIS map can unveil the most vulnerable neighborhoods during a hurricane or the safest evacuation routes during a wildfire.

Engineering, too, finds a partner in GIS. Whether it's designing resilient telecommunication networks, sculpting roads that weave through challenging terrains, or envisioning transport hubs, GIS offers tools and insights that drive precision and foresight.

How Do I Get a GIS Job?

Now, getting GIS jobs is made easy with Job In GIS. With hundreds of job listings throughout the world, you can search for opportunities. The best thing is that it's a platform with an interactive map allowing you to see the jobs available geolocated. Visit https://www.jobingis.com/ to learn more and start your search.

Frequently Asked Questions

What are the different types of GIS Data?

There are two types; the first is vector data, which represents information through points, lines, or polygons. This type can detail specific locations, routes, or areas on the Earth's surface. The second category is raster data, which is cell-based and encompasses datasets like aerial photographs or elevation representations. Such data is often pixelated and provides a grid-like perspective of features.

What is the difference between a certificate and a certification in GIS?

It's easy to mix up these terms, but they hold distinct meanings. A certification in GIS signifies recognized expertise in specific GIS facets, typically achieved by passing an exam. Notable examples include the GISP provided by the GIS Certification Institute (GISCI) or the array of certifications offered by Esri for their software products. On the other hand, a certificate in GIS is granted after completing a set of GIS-centric courses from an academic institution. While it doesn't equate to a degree, many employers might consider a GIS certificate on par with a degree in a related geography or GIS field.

What programming languages should I learn for GIS?

Python, given its compatibility with major GIS platforms like ArcGIS and QGIS. However, broadening your skill set with other languages, such as JavaScript, SQL, or R, can give you a competitive edge, especially if you aim to be a comprehensive GIS developer.

How do I start Learning GIS?

For those inclined towards self-paced learning, online GIS tutorials offer an excellent introduction. For a more structured approach, distance learning courses from reputable institutions can be a great option. Moreover, the growing prominence of GIS means that many educational entities now offer on-campus GIS courses and certifications, providing hands-on experience and access to seasoned professionals.


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