Which of the following best describes how global operations are applied in Map Algebra?

The best description of how global operations are applied in Map Algebra is to derive a singular value representative of the entire dataset. In the context of GIS and Map Algebra, global operations are those that consider all the cells in the analysis area simultaneously rather than focusing on individual cells or local neighborhoods. This allows for calculations such as total sums, averages, maximums, or minimums that produce a singular value representing the entire dataset.

For instance, if you were to perform a global average on a raster dataset, the output would be a single value reflecting the mean of all the raster cells' values. This type of operation is essential for understanding broad trends and patterns across spatial data, providing insights that may not be evident from local operations, which only focus on smaller areas within the dataset.

The other options describe processes or contexts where operations are localized, focused on specific zones or distances, rather than on deriving a holistic representation of the entire dataset.