The Okavango River Basin –Challenges &

Opportunities.

OKACOM, 2003, Corvallis

Several slides compiled by Dr Peter Ashton – CSIR (2002)

MAKGADIKGADI CATCHMENT

Map sourced

from GEF Report on Okavango

Delta Study

100 km

N

ZAMBIA

Boteti River basin

ZIMBABWE

NAMIBIA

ANGOLA

BOTSWANA R.S.A.

Deception Pan basin

Ntwetwe Pan basin

Sowa Pan basin

Okavango Basin

Lake Ngami

Okwa R.

Nata R.

Omatako R.

Cubango R.

Okavango Delta

Cuito R.

Kavango R.

Cuando R.

Chobe R.

Zambezi R.

RAINFALL DISTRIBUTION

300400500600700800900

10001100120013001400

M.A.P. (mm)

ZAMBIA

NAMIBIA

BOTSWANA

ZIMBABWE

ANGOLA

L. Ngami

L. Xau MakgadikgadiPans

Maun

Savuti R.Rundu

Kavango R.

Cuito R.Cubango R.

Nata R.Boteti R.

Zambezi R.

Zambezi R.

Cuando R.

Omatako R.

Chobe R.

OKAVANGODELTA

20° E

15° S

20° S

VARIABLE ANNUAL INFLOWS AT MOHEMBO (1933 - 2001)

Per

cen

tag

e o

f m

ean

an

nu

al i

nfl

ow

40

60

80

100

120

140

160

180

1930 1940 1950 1960 1970 1980 1990 2000

Time (Years)

5-yearMovingaverage

Max.: 16,145 x 106 m3

Mean: 9,863 x 106 m3

Min.: 5,321 x 106 m3

TIMING OF DELTA RAINFALL INFLOW AND OUTFLOW

0

50

100

1000

500

0

40

20

0J J A S O N D J F M A M J J A S O N D J F M

Rai

nfa

ll (m

m)

Infl

ow

(10

6 m

3 )O

utf

low

(10

6 m

3 ) Outflow Volume(Thamalakane)

Inflow Volume(Mohembo)

Rainfall(Average of Shakawe

plus Maun)

DELTA WATER BALANCERIVER INFLOWS

+ 76 %

OUTFLOW- 3 %

DIRECTEVAPOTRANSPIRATION

- 84 %

DIRECTRAINFALL

+ 24 %

RIPARIAN SOILS &GROUNDWATER

- 13 %

PROJECTED WATER NEEDS IN OKAVANGO BASIN

0

2040

6080

100120

140

Angola Botswana Namibia

Wat

er v

olu

me

(mil

lio

n c

ub

ic

met

res/

year

)

2000 2020

Anticipated total water requirement = 300 million m3 / year in 2020

RATIFIED INTERNATIONAL CONVENTIONS

CountryTreaty / Protocol Ratification Date

Ramsar UNCBD UNCCD UNCSW UNFCCC

Angola N/P 01/04/98 30/06/97 N/P 17/05/00

Botswana 09/12/96 12/10/95 11/09/96 N/P 27/01/94

Namibia 23/08/95 16/05/97 16/05/97 N/P 19/05/95

N/P = Not yet party to Treaty / Protocol

RAMSAR SITE LOCATION

ZAMBIA

NAMIBIA

BOTSWANA

ZIMBABWE

ANGOLA

L. NgamiL. Xau Makgadikgadi

Pans

Maun

Savuti R.Rundu

Kavango R.

Cuito R.Cubango R.

Nata R.

Boteti R.

Zambezi R.

Zambezi R.

Cuando R.

Omatako R.

Chobe R.

OKAVANGODELTA

20° E15° E

15° S

20° S

Boundary of the Okavango Delta RAMSAR site

MOSAIC OF HABITATS

The Okavango Delta has an enormous variety of

different habitat types and a diverse array of aquatic

and terrestrial species

OKAVANGO – CUITO CONFLUENCE

Cuito RiverKavango River

ANGOLA

NAMIBIA