A method including: receiving a base map that is divided into geographical base regions, each of the geographical base regions having a measure of a first parameter; receiving a plurality of secondary maps that are each divided into a plurality of geographical regions, each of the geographical regions having a measure of a secondary parameter; determining a total overlap percentage for each of the secondary maps relative to the base map, the total overlap percentage for one of the secondary maps being an average of overlap percentages of each of the geographical regions of the one of the secondary maps with the geographical base regions of the base map; receiving a selection of one of the secondary maps; and applying the secondary parameter of the selected secondary map to each of the geographical base regions of the base map.