Which of the following demographic changes is not the likely result of a natural disaster? a significant reduction in the population of the young occurs because they are more vulnerable to infectious diseases spread by unsanitary conditions. birth rates rise dramatically during droughts and famines, unlike in other natural disasters. population declines because families tend to migrate away from places after a large disaster occurs. a significant reduction in the population of the elderly because they are more vulnerable to infectious diseases spread by unsanitary conditions. population declines because natural disasters act as a push factor driving people away from the area.