Final answer:
From 1972 to 2005, Cairo experienced uncontrolled and chaotic expansion, with its urban footprint marked by the rapid creation of slums and squatter settlements lacking basic services, contributing to various urban challenges.
Step-by-step explanation:
For the period from 1972 to 2005, the expansion of Cairo's urban footprint is best described as uncontrolled and chaotic expansion. This period was characterized by rapid growth that resulted in a sprawl of self-constructed slums and squatter settlements lacking essential public services like electricity and sewage disposal. Such expansion typically leads to significant urban problems, including traffic congestion, trash buildup, high crime rates, health problems, and air pollution. Moreover, the pattern of urban development often involved the creation of suburban communities by large land developers, with a tendency towards poorly planned, sprawling suburbs that put economic and service strains on city infrastructure and resources.
The process of urban expansion follows a pattern where new waves of the population add rings of informal housing outward from the central business district (CBD), a phenomenon known as in situ accretion. Over time, as these areas mature, city services gradually extend to accommodate the growing population, and then new rings of squatter settlements emerge, further expanding the city's footprint. This pattern exemplifies the uncontrolled and chaotic nature of urban spread, contributing to the complex challenges faced by growing African cities like Cairo.