The source of the Okavango Delta
Spurred
by huge subtropical storms, the Cubango River rises in central Angola,
flows through Namibia as the Kuvango River and finally enters Botswana
as the Okavango River at Mohembo in the north. With it comes some 11
billion cubic metres of water each year which drains away through a maze
of lagoons, channels and islands before disappearing into the Kalahari
wastes of the south.
This is
the Okavango Delta, some 15000 square kilometres of wetland with a
special diversity of fauna and flora.
The Okavango
River is funnelled through parallel faults of the Panhandle as a
deep and fast-flowing river before being confronted by another
perpendicular fault with a sudden increase in gradient. This slows the
flow of water considerably as it spreads into relatively shallow
sediment with a fall of only 62 metres over approximately 250 kilometres.
The Okavango's seasonal floods
An
important feature of the Okavango is the seasonal flooding which
commences in mid-summer in the north and ends about six months later in
the south. This results in a cyclical motion of water rising in the
north as it recedes in the south during summer, and a rising in the
south as it drops in the north during winter. The nature of the annual
floods is gentle with floodplains and islands disappearing under water
and then reappearing in an ever-changing landscape at the end of each
season - this is particularly pronounced in the central Okavango.
The flood zones
The Delta
can be reasonably well divided between a permanently flooded zone in the
north and a seasonally flooded zone in the south.
- The
northern zone includes the panhandle with its riverine forest
fringes immediately adjacent to arid Kalahari woodlands and
depending upon the inflow from Angola a vast wetland of up to 12000
square kilometres of islands, reed beds, channels, forest banks and
permanent water ways.
- The
seasonally flooded zone has large Kalahari sandveld islands with dry
and deciduous woodlands fringed by wide grassy floodplains that are
heavily influenced by the seasonal floods.
Moremi
The
Moremi Game Reserve and its surrounds is the focal point for safaris
in the Okavango and includes habitats from both the permanently and
seasonally flooded zones. With the exception of the eastern
"tongue" of Moremi, access into the Okavango Delta is by
aircraft.
Review
the Botswana
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