Which statement describes the purpose of a Geographic Information System (GIS) in environmental science, and lists three common spatial analyses you might perform?

• A. To store, visualize, and analyze spatial environmental data; analyses include buffer/watershed analysis, hotspot/cluster analysis, and overlay/intersection/interpolation.
• B. To automatically replace field sampling with digital data.
• C. To perform chemical analyses in the laboratory.
• D. To replace regulatory reporting entirely.

Answer: (A)

Geographic Information Systems are used to store, visualize, and analyze spatial environmental data, so you can see how different factors interact across space and make informed decisions about where and how to act.

The three common spatial analyses reflect typical GIS capabilities in environmental science. Buffering or watershed analysis helps you understand how processes influence nearby areas or drainage paths: a buffer creates a zone around a feature such as a pollutant source to assess potential exposure, while watershed analysis delineates drainage basins to follow how water and transported contaminants move through the landscape. Hotspot or cluster analysis uses spatial statistics to identify areas with unusually high or low values, guiding where to focus monitoring or remediation efforts. Overlay or intersection analyses combine multiple layers to examine how different factors relate—like pollution sources over land use, or habitat suitability over climate variables—while interpolation fills in gaps between sampled points to produce continuous surface estimates (for example, contaminant concentration or temperature) across the study area. This combination—storing, visualizing, and applying these analyses—illustrates how GIS supports environmental decision-making without replacing field sampling, laboratory work, or regulatory reporting.