Geographicalá AND CLIMATIC

Facts on Kisumu

 

Kenya lies across the equator on the east of the African continent. Neighbouring countries include Ethiopia to the north, Somalia to east, Tanzania to south, Uganda to west and Sudan to north-west.

 

Kisumu is situated on the west of Kenya.

 

KISUMU

 

 

LOCATION:

1.     Mara, Muwanza and West Lake, Tanzania; North Buganda, South Buganda and Busoga, Uganda; and Nyanza and Western, Kenya.

 

  1. 0:21N-3:00S, 31:39-34:53E; 1,134 m above sea level.

 

DESCRIPTION:

Lake Victoria, the largest of all African Lakes, is also the second widest freshwater body in the world. Its extensive surface belongs to the three countries; the northern half to Uganda, the southern half to Tanzania, and part of the northeastern sector to Kenya. The lake occupies a wide depression near the equator, between the East and West Great Rift Valleys, but its drainage basin is relatively small, being slightly less than three times the lake's surface in area. The lake water is drained at a rate of about 600 m3 sec-1, at Jinja on the northern shore, into the Victoria Nile which flows northward via Lake Albert and the White Nile forming the uppermost reaches of the Nile River.


The lake shore is highly indented, and there are many isles in the lake, some of which, especially the Sesse Group, are known for their beautiful landscape, health resorts and sightseeing places. Abundant prehistoric remains found around the lake indicate the early development of agriculture. There are a number of coastal towns such as Kisumu (Kenya), Entebe (Uganda), Bukoba, Muwanza and Musoma (Tanzania), connected with each other by ship routes and also to the cities of the Indian Ocean coast by railways. The dam constructed in 1954 at Owen Falls on the Victoria Nile supplies electricity and water for various uses in Uganda and Kenya.

 

 

 

PHYSICAL DIMENSIONS

 

Surface area [km2]

68,800

Volume [km3]

2,750

Maximum depth [m]

84

Mean depth [m]

40

Water level

Regulated

Length of shoreline [km]

3,440

Residence time [yr]

23

Catchment area [km2]

184,000

 

 

 

 

PHYSIOGRAPHICAL FEATURES

 

Climatic data of Kisumu

 

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Ann.

Mean temp [deg OC]

24.0

23.6

23.9

23.2

23.1

23.3

21.8

22.1

22.8

23.4

23.3

23.3

23.1

Precipitation [mm]

57

70

160

195

177

101

68

96

79

64

106

105

1,278

 

 

 

 

SOCIO-ECONOMIC CONDITIONS

 

LAND USE IN KENYAN PART OF THE CATCHMENT AREA

 

1985

 

Area [km2]

[%]

Natural landscape

29,500

62

- Woody vegetation

7,000

15

- Herbaceous vegetation

22,500

47

Agricultural land

15,500

32

- Crop field

11,000

23

- Pasture land and fallow land

4,500

9

Residential area and others

2,700

6

Total

47,700*

100

* 26% of the whole catchment area.

 

 

1.      The main types of woody vegetation is Savanna woodland (Acacia, Albizzia and Butyrospermum).

2.      The main species of herbaceous vegetation is Cymbopogon, Hyparrhenia, Londetia and Cyperus papyrus.

3.      The main kinds of crop are Maize, cotton, sisal, tobacco, beans, sugar cane, coffee, sorghum, millet, wheat and root crops (cassava, etc.).

4.      The levels of fertiliser application on the crops fields is light.

  1. There is a decrease in the forest area of Kisumu due to the high population and the excessive cultivation.

 

 

INDUSTRIES IN THE CATCHMENT AREA AND THE LAKE

 

1985

 

Gross product per year [mill. Kú

Main products or major industries

Primary industry

-Cash crops

89

Value Coffee, tea, cotton, sugarcane

-Animal husbandry

97

added Milk, meat

-Fisheries

10

Nile perch, tilapia

-Staple crops

181

 

Secondary industry

400 Gross

Coffee & tea processing, sugar, pulp, dairy product, foods, leather, textile

 

 

POPULATION IN THE CATCHMENT AREA

 

1985

 

Population

Populationdensity [km-2]

Major cities (population)

Urban

630,000

 

 

Rural

7,480,000

Kisumu, Eldoret

 

Total

8,110,000

170

 

 

MAIN USES OF THE LAKE

1.     Source of water

2.     Navigation and transportation

3.     Recreation (yachting)

4.     Fisheries.

 

THE LAKE AS A WATER RESOURCE

1986

 

Use rate [m3 sec-1]

Domestic

0.17 (for Kisumu)

Irrigation

1.7 (near Kisumu)

 

 

DETERIORATION OF LAKE ENVIRONMENTS AND HAZARDS

ENHANCED SILTATION

  1. Extent of damage (Q2): Not serious.
  2. Supplementary notes (7): 4,000,0000 [t yr-1] from 47,000 km2 of catchment (an estimate); 0.5-1.0 [mm yr-1] as lake sediment.

TOXIC CONTAMINATION

  1. Present status (Q2): Detected but not serious.
  2. Main contaminants, their concentrations and sources (7) 1984

Kisumu Bay of Winam Gulf

Name of contaminants

Concentrations [ppb] Fish*

Main Sources

DDE

4.3

Pesticide

* Lates niloticus (Nile perch) on wet weight basis.

  1. Environmental quality standards for contaminants in the lake (Q2)
    Now follow WHO ambient standards.
  2. Supplementary notes (8)
    Nzoia River draining into the lake is contaminated with pesticide residues; DDT 0.3 ppm, DDE 0.3 ppm, BHC 0.2 ppm, Toxaphene 0.2 ppm in 1982.

 

EUTROPHICATION

  1. Nuisance caused by eutrophication* (7)
    Unusual algal bloom: Microcystis aeruginosa, Anabaena circinalis.
    * In Winam Gulf.
  2. Supplementary notes (8)
    Mesotrophic in the main body of the lake. Although nutrient loads to the lake are not known, 400 kg m-2 yr-1 of T-N and 20 kg km-2 yr-1 of T-P are measured as averages of 24 points in the watershed of Nzoia River, a major tributary of the lake.

 

WASTEWATER TREATMENTS

GENERATION OF POLLUTANTS IN THE CATCHMENT AREA

 

Measurable pollution with limited wastewater treatment.
* In Kenyan part.

 

SANITARY FACILITIES AND SEWERAGE

  1. Municipal wastewater treatment systems
    No. of municipal wastewater treatment systems: 4 (trickling filter plants, oxidation ponds).
  2. Industrial wastewater treatment systems
    Anaerobic ponds and aerobic oxidation ponds are used by very many factories (sugar, textile, dairy and paper factories).

 

IMPROVEMENT WORKS IN THE LAKE

None.

 

DEVELOPMENT PLANS

An integrated regional development master plan for 1987-2005 is being drawn up by the Lake Basin Development Authority (Kenya) for agricultural, industrial, livestock, fishery and infrastructure developments.

 

LEGISLATIVE AND INSTITUTIONAL MEASURES FOR UPGRADING LAKE ENVIRONMENTS

NATIONAL AND LOCAL LAWS CONCERNED*

  1. Names of the laws
    1. The Water Act
    2. The Public Health Act
    3. The Poisonous Substance Act (indirect)
    4. The Pesticides Control Act (indirect)
  2. Responsible authorities
    1. Ministry of Water Development
    2. Ministry of Health
  3. Main items of control
    1. Sewage effluent and industrial effluent

*Kenya only.

 

INSTITUTIONAL MEASURES*

  1. Ministry of Water Development, Nairobi, Kenya
  2. Marine Fishery Development, Kisumu, Kenya
  3. Lake Basin Development Authority, Kisumu, Kenya

*Kenya only.

 

RESEARCH INSTITUTES ENGAGED IN THE LAKE ENVIRONMENT STUDIES

  1. Kenya Marine Fisheries Research Institute, Kisumu
  2. Tanzania Freshwater Fisheries Research
  3. Uganda Freshwater Fisheries Research Organization, Jinja
  4. Lake Basin Development Authority, Kisumu

 

SOURCES OF DATA

  1. Questionnaire filled by Dr. P. B. 0. Ochumba, Kisumu Laboratory, Kisumu. (Q1)
  1. Questionnaire filled by Dr. M. Nakashima, International Development Centre, Tokyo. (Q2)
  1. Serruya, C. & Pollinger, U. (1983) Lakes of the Warm Belt. p. 569. Cambridge University Press, Cambridge.
  2. Talling, J. F. (1957) Comparative problems of phytoplankton production and photosynthetic productivity in a tropical and temperate lake. Mem. Ist. Idrobiol., 18, Suppl.: 339-424.
  3. Shimonaka, K. (ed.)(1984) Grand World Atlas (Sekai Dai Chizu-cho). p. 273. Heibon-sha, Tokyo.*
  4. Payne, A. I. (1986) The Ecology of Tropical Lakes and Rivers. John Wiley and Sons Ltd., New York.
  5. Ochumba, P. B. O. (1987) Water Quality Bulletin, 12(3): 119-122.
  6. Ssentongo, G. W., Durand, J. R. & Harbott, B. (1981) The rational exploitation of African aquatic ecosystems. The Ecology and Utilization of African Inland Waters (ed. Symoens, J. J., Burgis, M. & Gaudet, J. J.), pp. 167-175. United Nations Environment Programme, Nairobi.
  7. Lake Basin Development Authority (1985) The Technical Annex to the Final Report on the Current and Future Implications of Development to the Aquatic Environment of Lake Victoria.
  8. Chabeda, P. I. M. (1983) A Survey of Eutrophication and Water Pollution Load in Four Rivers of the Northern Half of the Lake Basin Development Authority.
  9. Water Quality and Pollution Control Section (1978) Limnological Investigation of Lakes in Kenya 1976-1977. Technical Report No. 6. Resource Section, Water Department of Kenya, Nairobi.
    * Printed in Japanese. The title is tentatively translated into English with the original title in romanized Japanese in parentheses.