THE VICTORIA FALLS:

The Zambezi rises in Northern Zambia near Kalene Hill. This watershed is also the origin of one of the tributaries of the Congo. The Zambezi flows south-west into Angola, returning the Zambia where it flows south through the Barotse Plain and on to the Caprivi swamps where it is joined by the Chobe River. From this point it takes an easterly course, forming the border between Zambia and Zimbabwe and on through Mozambique to the Indian Ocean. Its total length is 2 700 kilometres, and it is Africa’s fourth longest river.

At several places in its course it encounters sudden bands of comparatively hard rock through which it must excavate its bed, and at these points, rapids and sometimes waterfalls are formed, marking the uneven erosion of th underlying rock surface. In other areas the river bed is formed of a uniform type of rock and therefore erosion is comparatively even and the river flows smoothly. Usually in such peaceful stretches of the river, the bed is wide, and deposition of material such as sand or gravel, carried along by the river from further up-stream, forms bars or islands. In places where hard rock is encountered, the river tends to narrow and deepen, cutting the easiest course through the barrier, and here erosion rather than deposition is the rule.

In the Victoria Falls area we find both these varieties of river “character” exaggerated to a unique degree. Up-stream from the Falls is a stretch of about twelve kilometres where the river is smooth-running, depositing sand which forms islands, such as Kandahar and Long Islands. About three kilometres up-stream from the Falls, there is a sudden southward bend in the river, the current, becomes faster and more uneven and finally, after a short stretch of rapids, the whole river, here 1 700 metres wide, plunges into a chasm of 108 metres deep which cuts right across its course. Thus a river of nearly two kilometres (over a mile) in width becomes one of only a fraction of that width in a matter of seconds. The river continues through a series of steep, narrow gorges which form a zig-zag pattern for the first eight kilometres and then straighten out into the Batoka Gorge which runs in an easterly direction for about 100 kilometres to the Gwembe Valley where the river has been dammed to form Lake Kariba.