  In the present work we study the relationship between population allocation
and the combined effects of urban size and energy consumption, for two given
areas and through a major part of the twentieth century. Along these lines a
general application model is laid down which relates city-growth rates to
initial inhabitants and to exosomatic energy increment, the deviations from it
showing order in space and time; as shown in a series of maps which hint at
unaccounted socioeconomic factors. The study of the maps by means of spectral
analysis allows finding patterns which reinforce over time, in such a manner
that spatial frequencies can be determined whose weight increases up so
granting surface evolution estimation.
