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Rainfall and drought in equatorial east Africa during the past 1,100 years


Knowledge of natural long-term rainfall variability is essential for water-resource and land-use management in sub-humid regions of the world. In tropical Africa, data relevant to determining this variability are scarce because of the lack of long instrumental climate records and the limited potential of standard high-resolution proxy records such as tree rings and ice cores1,2,3. Here we present a decade-scale reconstruction of rainfall and drought in equatorial east Africa over the past 1,100 years, based on lake-level and salinity fluctuations of Lake Naivasha (Kenya) inferred from three different palaeolimnological proxies: sediment stratigraphy and the species compositions of fossil diatom and midge assemblages. Our data indicate that, over the past millennium, equatorial east Africa has alternated between contrasting climate conditions, with significantly drier climate than today during the ‘Medieval Warm Period’ ( ad 1000–1270) and a relatively wet climate during the ‘Little Ice Age’ ( ad 1270–1850) which was interrupted by three prolonged dry episodes. We also find strong chronological links between the reconstructed history of natural long-term rainfall variation and the pre-colonial cultural history of east Africa4, highlighting the importance of a detailed knowledge of natural long-term rainfall fluctuations for sustainable socio-economic development.

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Figure 1: Sedimentological and biological evidence for past lake-depth and salinity fluctuations in the Crescent Island Crater basin of Lake Naivasha.
Figure 2: Comparison of Crescent Island Crater history with documented and reconstructed climate-proxy data.


  1. Houghton, J. T. et al. (eds). Climate Change 1995 The Science of Climate Change (Cambridge Univ. Press, 1995).

    Google Scholar 

  2. Nicholson, S. E. The Physical Geography of Africa (eds Goudie, A. S., Adams, W. M. & Orme A.) 60–75 (Oxford Univ. Press, 1995).

    Google Scholar 

  3. Nicholson,, S. E. in The Limnology, Climatology and Paleoclimatology of the East African Lakes (eds Johnson, T. C. & Odada, E.) 25– 56 (Gordon & Breach, Newark, 1996).

    Google Scholar 

  4. Webster,, J. B. in Chronology, Migration and Drought in Interlacustrine Africa (ed. Webster J. B.) 1–37 (Longman & Dalhousie Univ. Press, Dalhousie, 1979).

    Google Scholar 

  5. Verschuren, D. Sedimentation controls on the preservation and time resolution of climate-proxy records from fluctuating lakes. Quat. Sci. Rev. 18, 821–837 (1999).

    Article  ADS  Google Scholar 

  6. Ojiambo, B. S. & Lyons,, W. B. in The Limnology, Climatology and Paleoclimatology of the East African Lakes (eds Johnson, T. C. & Odada, E.) 267–278 (Gordon & Breach, Newark, 1996).

    Google Scholar 

  7. Nicholson,, S. E. in Environmental Change and Response in East African Lakes (ed. Lehman J. T.) 7–35 (Kluwer, Dordrecht, 1998).

    Book  Google Scholar 

  8. Verschuren, D. Reconstructing fluctuations of a shallow East African lake during the past 1800 years from sediment stratigraphy in a submerged crater basin. J. Paleolimnol. (in the press).

  9. Kilham, P. Mechanisms controlling the chemical composition of lakes and rivers: data from Africa. Limnol. Oceanogr. 35, 80– 83 (1990).

    Article  ADS  CAS  Google Scholar 

  10. Fritz, S. C., Cumming, B. F., Gasse, F. & Laird,, K. R. in Diatoms: Applications to the Environmental and Earth Sciences (eds Stoermer, E. & Smol, J. P.) 41–72 (Cambridge Univ. Press, 1999).

    Book  Google Scholar 

  11. Verschuren, D. Taxonomy and ecology of fossil Chironomidae (Insecta, Diptera) from Rift Valley lakes in central Kenya. Arch. Hydrobiol. Suppl. 107 , 467–512 (1997).

    Google Scholar 

  12. Verschuren, D., Tibby, J., Sabbe, K. & Roberts, N. Effects of lake level, salinity and substrate on the benthic invertebrate community of a shallow tropical-African lake ecosystem. Ecology (in the press).

  13. Gasse, F., Juggins, S. & Ben Khelifa, L. Diatom-based transfer functions for inferring hydrochemical characteristics of African paleolakes. Palaeogeogr. Palaeoclimatol. Palaeoecol. 117, 31–54 ( 1995).

    Article  Google Scholar 

  14. Kilham, P., Kilham, S. S. & Hecky, R. E. Hypothesized resource relationships among African planktonic diatoms. Limnol. Oceanogr. 31, 1169–1181 (1986).

    Article  ADS  Google Scholar 

  15. Harper, D. M., Phillips, G., Chilvers, A., Kitaka, N. & Mavuti, K. Eutrophication prognosis for Lake Naivasha, Kenya. Verh. Int. Verein. Limnol. 25, 861–865 (1993).

    CAS  Google Scholar 

  16. Harper, D. M. The ecological relationships of aquatic plants at Lake Naivasha, Kenya. Hydrobiologia 232, 65–71 (1992).

    Article  CAS  Google Scholar 

  17. Cohen, A. S., Talbot, M. R., Awramik, S. M., Dettman, D. L. & Abell, P. Lake level and paleoenvironmental history of Lake Tanganyika, Africa, as inferred from late Holocene and modern stromatolites. Geol. Soc. Am. Bull. 109, 444–460 (1997).

    Article  ADS  CAS  Google Scholar 

  18. Halfman, J. D., Johnson, T. C. & Finney, B. P. New AMS dates, stratigraphic correlations and decadal climatic cycles for the past 4 ka at Lake Turkana, Kenya. Palaeogeogr. Palaeoclimatol. Palaeoecol. 111, 83– 98 (1994).

    Article  Google Scholar 

  19. Owen, R. B. & Crossley, R. Recent sedimentation in lakes Chilwa and Chiuta, Malawi. Palaeoecol. Afr. 20, 109–117 (1989).

    Google Scholar 

  20. Mann M. E., Bradley, R. S. & Hughes, M. K. Northern hemisphere temperatures during the past millennium: inferences, uncertainties, and limitations. Geophys. Res. Lett. 26, 759–762 ( 1999).

    Article  ADS  Google Scholar 

  21. Kutzbach, J. E. & Street-Perrott, F. A. Milankovitch forcing of fluctuations in the level of tropical lakes from 18 to 0 kyr BP. Nature 317, 130–134 (1985).

    Article  ADS  Google Scholar 

  22. Roberts, C. N. et al. Timing of the Younger Dryas event in East Africa from lake-level changes. Nature 366, 146– 148 (1993).

    Article  ADS  Google Scholar 

  23. Street-Perrott, F. A. & Perrott, R. A. Abrupt climate fluctuations in the tropics: the influence of Atlantic Ocean circulation. Nature 348, 607–612 (1990).

    Article  ADS  Google Scholar 

  24. Stuiver, M. & Reimer,, P. J. Extended 14C data base and revised CALIB 3.0 14C age calibration program. Radiocarbon 35, 215–230 (1993).

    Article  Google Scholar 

  25. Lean, J., Beer, J. & Bradley, R. S. Reconstruction of solar irradiance since 1610: implications for climate change. Geophys. Res. Lett. 22, 3195–3198 (1995).

    Article  ADS  Google Scholar 

  26. Knox, J. C. Large increases in flood magnitude in response to modest changes in climate. Nature 361, 430–432 (1993).

    Article  ADS  Google Scholar 

  27. Webster, J. B. Drought, migration and chronology in the Lake Malawi littoral. Transafr. J. Hist. 9, 70–90 (1980).

    Google Scholar 

  28. Connah,, G. African Civilizations (Cambridge Univ. Press, 1987).

    Google Scholar 

  29. Rind, D. & Overpeck, J. Hypothesized causes of decade-to-century-scale climate variability: climate model results. Quat. Sci. Rev. 12, 357–374 (1993).

    Article  ADS  Google Scholar 

  30. Woodhouse, C. A. & Overpeck, J. T. 2000 years of drought variability in the central United States. Bull. Am. Meteorol. Soc. 79, 2693–2714 (1998).

    Article  ADS  Google Scholar 

  31. Line, J. M., ter Braak, C. J. F. & Birks, H. J. B. WACALIB version 3. 3: A computer program to reconstruct environmental variables from fossil assemblages by weighted averaging and to derive sample-specific errors of prediction. J. Paleolimnol. 10, 147–152 ( 1994).

    Article  ADS  Google Scholar 

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We thank K. Mavuti, B. Ammann, F. Janssen and H. E. Wright for field assistance; the Lake Naivasha Riparian Association for lake access; F. Gasse for use of the African diatom reference and calibration data sets; and S. Fritz, F. Gasse, K. Kelts, F. Oldfield, J. P. Smol, B. Tinsley and H. E. Wright for comments on the manuscript. This work was supported by NSF, the Quaternary Paleoecology Program at the University of Minnesota, and by fellowships from NOAA and FWO-Vlaanderen (D.V.) The fieldwork was conducted with permission from the Office of the President of the Republic of Kenya to K. Mavuti.

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Correspondence to Dirk Verschuren.

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The data presented here are archived at the World Data Center-A for Paleoclimatology.

Supplementary information

Figure 1

Fossil diatom taxa in the sediment record of Crescent Island Crater (Lake Naivasha, Kenya) (DOC 783 kb)

Figure 2

Fossil chironomid taxa in the sediment record of Crescent Island Crater (Lake Naivasha, Kenya) (DOC 764 kb)

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Verschuren, D., Laird, K. & Cumming, B. Rainfall and drought in equatorial east Africa during the past 1,100 years. Nature 403, 410–414 (2000).

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