Google Earth Engine vs. Traditional Desktop GIS for Large-Area Land Cover Mapping

We get asked fairly often why we run large-area land cover mapping through Google Earth Engine rather than a traditional ArcGIS Pro or ERDAS Imagine desktop workflow. The honest answer is: for small study areas, it often doesn't matter much. For national or multi-region mapping, it changes what's realistically achievable.

The Scale Problem

A single Landsat scene is a few hundred megabytes. A cloud-free annual composite across an entire country, built from dozens of scenes with cloud-masking and compositing logic, is a different order of computational problem — one that pushes desktop hardware and local storage past what's practical for a normal project timeline.

What Earth Engine Actually Changes

Earth Engine moves the compute to Google's infrastructure and the data to Google's petabyte-scale public catalog, meaning a classification workflow that might take days of local processing and terabytes of downloaded imagery runs in minutes to hours, with no local storage burden at all. For a 10-year, multi-epoch national land cover change study — like the kind we regularly deliver — this is the difference between a feasible project and one that isn't.

Where Desktop GIS Still Wins

Earth Engine is not a replacement for desktop GIS. Once you have your classified rasters, cartographic production, complex vector geoprocessing, and integration with other spatial datasets is still often faster and more flexible in ArcGIS Pro or QGIS. Our workflow is almost always hybrid: heavy-lifting classification and time-series analysis in Earth Engine, final production and integration in desktop GIS.

The Practical Takeaway

If your land cover mapping study area is a single small catchment, either platform works fine — pick whichever your team already knows well. If you're mapping a province, a country, or running a multi-year time series, the compute and storage economics of Earth Engine aren't just convenient, they're often the deciding factor in whether the analysis is achievable on your budget and timeline at all.