Which of the following is an ancillary technique often used in mapping?

Dasymetric mapping is considered an ancillary technique used in mapping because it provides a way to improve data distribution accuracy by utilizing additional information about the areas being mapped. This technique involves the redistribution of statistical data to more accurately reflect the underlying population or variable distribution within different regions, rather than using arbitrary boundaries like administrative or political borders.

Dasymetric mapping enhances the visualization of spatial data by incorporating land cover or land use data to delineate areas of similar characteristics. For instance, instead of treating a whole area as homogeneous, dasymetric mapping allows for differentiation by illustrating population density or resource availability within more specific zones, leading to more nuanced and informative maps.

In the context of mapping techniques, other methods such as choropleth and dot mapping provide valuable visuals as well; however, they may not adjust data in the same manner that considers additional spatial context. Static mapping simply refers to displayed maps that do not change or interact, lacking the dynamic adjustment that dasymetric mapping provides through its improvement of data representation. Thus, dasymetric mapping stands out for its capability of refining the accuracy and relevance of spatial information in a varied landscape.