Table 1.

Factors selected using principal component analysis

Factor	Groups of variables having unique dimensions
1	Perennial, orchard and rangeland
2	Recreation area and golf course
3	Deciduous forest and mine
4	Reservoir and pasture/farm house
5	City and aquaculture land
6	Institutional land, build-up village and natural water body
7	Field crop and pit
8	Marsh/swap/rice paddy and gasoline station/workshop
9	Transportation/communication, horticulture and landfill
10	Industrial area and forest plantation
11	Perennial/orchard and cemetery
12	Marsh/swamp and paddy field

One group is treated as one variable during processing of data. Factors scores were used to investigate the contribution of each variable to the dengue indices.