What issue would be most likely to concern the region within the yellow circle? severe drought rapid urbanization suburban overpopulation destruction of the rain forests

Ibelieve the answer would be the overpopulation

An informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.