Geographic Information Science (GIS) and Mapping

"A map projection refers to any of the numerous techniques employed in cartography to depict the three-dimensional surface of the Earth or other spherical objects on a two-dimensional plane." -- GISLounge.com

Think of it this way!

If you take an orange peel and try to lay it flat on a table surface - what happens to the orange peel? Projections are a method of trying to display the surface of the earth on a flat medium. Different projections may be better or worse at displaying a specific set of data - picking a map projection that fits your area of study will make it easier for readers to understand it visually.

Mercator is the typical default projection used in many mapping platforms - however, this can be problematic as it distorts many areas of the map. The Equal Earth projection is starting to become a recommended projection to use when creating mapping projects as it is more true to landmass size.

Spatial Analysis refers to the process that we used to classify and interpret geospatial/GIS data. Different methodologies and tools can be used to break data down to better understand the trend in information. This type of analysis is effective when knowing your expectations of the final result - although your results and process may change, this will help determine the workflow needed to build an analysis. For example, if you need to determine the slope of a region, the end result of ‘finding slope’ will indicate what type of spatial analysis tools are needed.

While spatial analysis refers to a method of analyzing data, geoprocessing includes the tools needed to perform the process. Common geoprocessing tools can include:

• Clip - extra a specific area of a region for additional analysis
• Buffer - look at the proximity of surrounding features
• Dissolve - remove borders or features to have a better view of an area
• Intersect - with multiple sets of data, extract areas that intersect to see common locations
• Union - combine multiple sets of data and preserve all features
• Erase/Difference - remove unnecessary areas in the data that are not needed for analysis

Different software packages may off additional tools, combinations of these tools, or allow a user to build a model of these tools. These models will create a defined process that can be used throughout the project and a visual process to view the analysis.

Learn more about Spatial Analysis and Geoprocessing

7 Geoprocessing Tools Every GIS Analyst Should Know

What is Geographic Information Systems (GIS)?

ESRI: The Language of Spatial Analysis