Afi: the values in 2*2 km units of the ith (No.)
allocated indicators. Asi: the total value of the ith
(No.) allocated indicators in Nanjing City. Wfi: the
values in 2*2 km units of the ith (No.) weighting factors.
Wsi: the total value of the ith (No.) weighting factors
in Nanjing City.
Finally, data standardization was conducted as a standard procedure
before training. Standard deviation standardization was used to
eliminate the influence of the magnitudes. The land-use factors were
represented by individual area proportions (from 0% to 100%) for each
type, which were then individually standardized.