In a geospatial risk assessment workflow, which step follows data collection and preparation?

• A. Define objectives
• B. Build GIS models
• C. Clean and harmonize data
• D. Run scenario analyses

Answer: (C)

Cleaning and harmonizing data is the essential next step after gathering data, because it makes diverse datasets compatible for reliable analysis. Cleaning means fixing errors, addressing missing values, and removing duplicates, while harmonizing involves standardizing formats, units, coordinate reference systems, temporal resolutions, and attribute schemas across all sources. This alignment ensures that layers can be accurately combined in a GIS workflow, preventing inconsistencies that could skew risk assessments. Once the data are clean and harmonized, you can build GIS models with a solid, interoperable foundation and then run scenario analyses to compare potential outcomes. Defining objectives typically happens before data work, guiding what data are needed, while modeling and scenarios follow once data readiness is established.