The Khartoum-Omdurman conurbation : a growing megacity at the confluence of the Blue and White Nile Rivers

Khartoum is one of the largest cities in Africa, located immediately south of the junction of the Blue and White Nile rivers in central Sudan. The growth of the Greater Khartoum-Omdurman conurbation arose ¬– without a proper urban plan – from the agricultural wealth created through the completion of three major dams in 1925, 1937 and 1966, and mostly in the last three decades. Urban expansion was enabled by and helped to enhance the major agricultural expansion of the Gezira clay plains located to the south between the lower Blue and White Nile rivers. The confluence of the Blue and White Nile has been a focus of human settlement for at least 8,000 years, initially by semi-sedentary groups with a fishing-hunting-gathering lifestyle and later by Neolithic groups as shown by hundreds of archaeological sites. Today, Khartoum is a desert city and the hottest capital city on Earth, still very vulnerable to floods triggered by intense convectional storms. Such extreme events may become more common in future, representing a major geomorphological hazard in a city developed without urban plans. Moreover, uncontrolled urban and agricultural development is threatening most of the prehistoric cultural heritage of the region.