ABSTRACT
Megacities in low-income countries merit special attention because of the enormity of the challenges they face in providing services to sustain global economic activity while at the same time providing for a fast growing population. Megacities are very large agglomerations of people which have been defined as comprising between a range of 5-10 million people by various authors (Castells, 1996; Townroe, 1996; NRC, 1996). Around the turn of the century, it is estimated that there will be 21 megacities in the world each with more than 10 million inhabitants. Mexico City and Calcutta have already passed the barrier of 20 million inhabitants (Pugh, 1995; Castells, 1996). An important characteristic of megacities concern the rate at which they are growing. Between 1950 and 1990, urban growth increased with a factor 3.4, while rural growth increased with a factor 1.7. In developing countries this growth is faster than in industrialised countries, especially from 1975 onwards (Linden, 1996).
