Farming patterns along the Blue Nile south of Khartoum resemble French long farms. Specifically, each of the agricultural plots seen in this photograph has a characteristic rectangular shape in which one dimension is considerably longer than the other. This geometry is adopted in order to allow each individual plot access to water in irrigation canals along its narrow side. In this arid part of Sudan, much of the agriculture is highly concentrated around the Blue Nile (seen here) and the White Nile. Despite the dominantly arid climate, Sudan’s chief crop is cotton (a water-intensive crop), and 80% of its workforce is in agriculture. Much of Sudan’s population lives near the river. Indeed, almost 1 million of Sudan’s 33 million people live in the capital city of Khartoum, which is located north of this scene at the confluence of the Blue and White Nile rivers. Just beyond the reach of the life-giving water of these rivers are vast expanses of desert (reddish surface in lower left).
The section of the Blue Nile that meanders through this scene contains a characteristic pattern found in most dynamic river systems. Specifically, the bright areas along the river are concentrations of coarse-grained material such as sand. This material gets deposited on the inside of the meanders (or U-shaped bends) of the river, where the flow of water tends to be low.
January 1986, image STS-61C-34-60.