Changes in Vegetation Cover and Socio-Economic Transitions in a Coastal Lagoon (Kalametiya, Sri Lanka), As Observed by Teledetection and Ground Truthing, Can be Attributed to an Upstream Irrigation Scheme

  • L.P. Jayatissa
  • M.-C. Guero
  • S. Hettiarachchi
  • N. Koedam

Abstract

According to some non-scholarly reports, Kalametiya lagoon (dry zone of southern Sri Lanka, formerly 8.9 km2, now 7.5 km2) had been a moderately or high salinity water body and a very important centre of prawn fishery until the late 1960s. Most of the lagoon area had remained open water until then. An upstream irrigation project, the Udawalawa irrigation scheme, came into operation in 1967, increasing the freshwater inflow to the lagoon. The flora, fauna and water quality of the lagoon was reported to have changed since then.

The lagoon now is a shallow coastal water body with low salinity water. More than 75% of the lagoon is covered by freshwater species or mangrove species characteristic for water with a low salinity: Eichhornia crassipes, Typha latifolia resp. Sonneratia caseolaris. There is actually no commercially important fishery in the lagoon.

The present study was carried out to assess scientifically the said changes in the vegetation within a GIS, using aerial photographs taken in 1956 and 1994 and IRS IC, PAN+LISS III satellite images of 1997 in combination with ground surveys and information from a questionnaire-based survey.

It appeared from this work that the aerial cover by Sonneratia caseolaris has increased by more than 30 times over the period from 1956 to the recent dates. Also, the lagoon area with open water has been drastically reduced during the same period as a result of spreading of freshwater and low salinity plant species. The results strongly suggest that the locally reported changes (fisheries decline, water salinity decrease) can be corroborated by the observed profound changes in plant cover and that upstream water works may have had strong impacts on this ecosystem, thus causing these changes.

This study couples data obtained from retrospective aerial photograph series, from spaceborne imaging, from actual ground surveys and from questionnaires amongst elderly people to reconstruct decadal environmental change, thus attempting to fill the gap of lacking historical environmental data.

fisheries GIS irrigation mangrove Sonneratia caseolaris remote sensing Typha latifolia 

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References

  1. Abeywickrama, B.A.: 1960, 'The vegetation of the lowlands of Ceylon in relation to soil', in Tropical Soils and Vegetation. Proceedings of the Abidjan Symposium, Paris, pp. 87–92.Google Scholar
  2. Abeywickrama, B.A.: 1964, The Estuarine Vegetation of Ceylon. Proceedings of the Decca Symposium, Paris, UNESCO, pp. 207–210.Google Scholar
  3. Aksornkae, S., Maxwell, G.S., Havanond, S. and Panichsuko, S.: 1992, Plants in Mangroves, Thailand, Chalongrat Co. Ltd, pp. 102–105.Google Scholar
  4. Ball, M.C.: 1988, 'Ecophysiology of mangroves', Wetlands 6, 12–22.Google Scholar
  5. Bandaranayake, W.M., Sulthanbawa, M.U.S., Weerasekara, S.C. and Balasubramaniam, S.: 1974, 'Aglossary of sinhala and tamil names of the plants of Sri Lanka', The Sri Lanka Forester 11(3–4), 67–149.Google Scholar
  6. Banerjee, L.K., Sastry, A.R.K. and Nayar, M.P.: 1989, Mangroves in India. Identification Manual, Calcutta, India, Botanical Survey of India, pp. 1–113.Google Scholar
  7. Dahdouh-Guebas, F.: 2001, Mangrove Vegetation Structure Dynamics and Regeneration. PhD dissertation, Brussels, Belgium, Vrije Universiteit Brussel, pp. 1–317.Google Scholar
  8. Dahdouh-Guebas, F., Verheyden, A., De Genst, W. Hettiarachi, S. and Koedam, N.: 2000, 'Four decade vegetation dynamics in Sri Lankan mangroves as detected from sequential aerial photography: a case study in Galle', Bulletin of Marine Science 67(2), 741–759.Google Scholar
  9. Dassanayake, M.D.: 1981, A Revised Handbook to the Flora of Ceylon, Vol 3, NewDelhi, Amerind Publishing Co. Pvt. Ltd., pp. 450–452.Google Scholar
  10. Dassanayake, M.D.: 1983, A Revised Handbook to the Flora of Ceylon, Vol 4, NewDelhi, Amerind Publishing Co. Pvt. Ltd., pp. 127–132.Google Scholar
  11. Dassanayake, M.D.: 1991, A Revised Handbook to the Flora of Ceylon, Vol 7, New Delhi, Oxford and IBH Publishing Co. Pvt. Ltd., pp. 397–399.Google Scholar
  12. Dassanayake, M.D.: 1997, A Revised Handbook to the Flora of Ceylon, Vol 11, New Delhi, Oxford and IBH Publishing Co. Pvt. Ltd., pp. 187–291.Google Scholar
  13. Davis, T.A.W. and Richards, P.W.: 1933, 'The vegetation of Moraballi creek, British Guiana, an ecological study of a limited area of tropical rain forest. Part I', Journal of Ecology 21, 350–384.Google Scholar
  14. Davis, T.A.W. and Richards, P.W.: 1934, 'The vegetation of Moraballi creek, British Guiana, an ecological study of a limited area of tropical rain forest. Part II', Journal of Ecology 22, 106–155.Google Scholar
  15. De Silva K.H.G.M. and Balasubramaniam, S.: 1984–85, 'Some ecological aspects of the mangroves of the west coast of Sri Lanka', Ceylon Journal of Science (Biological Science) 17–18, 22–40.Google Scholar
  16. Duke, N.C., Ball, M.C. and Ellison, J.C.: 1998, 'Factors influencing biodiversity and distributional gradients in mangroves. Mangrove special issue', Global Ecology and Biogeography Letters 7, 27–47.Google Scholar
  17. Jayatissa, L.P.: 1987, Phytosociology of Some Coastal Water Bodies in Sri Lanka with Particular Emphasis on Three Lagoons, M. Phil. thesis, Matara, Sri Lanka, University of Ruhuna, pp. 1–162.Google Scholar
  18. Jayatissa, L.P., Dahdouh-Guebas, F. and Koedam, N.: 2002, 'A review of the floral composition and distribution of mangroves in Sri Lanka', Botanical Journal of the Linnean Society 138, 29–43.Google Scholar
  19. Liyanarachchi, P., Hettiarachi, S. and De Silva, M.P.: 1995,'Wetland site report and conservation management plan, Kalametiya and Lunama Kalapuwa's', Sri Lanka, Central Environmental Authority/Euroconsult, Sri Lanka, Ministry of Transport, Environment and Women's Affairs, pp. 1–83.Google Scholar
  20. Lovett, D.L.: 1981, A Guide to the Shrimps, Prawns, Lobsters and Crabs of Malaysia and Singapore, Occational Pub. no. 2. Faculty of Fisheries and Marine science, University of Pertanian Malaysia.Google Scholar
  21. Munro, I.S.R.: 1955, Marine and Freshwater Fishes of Ceylon, Canberra, Dept. of External Affairs, pp. 1–351.Google Scholar
  22. Pethiyagoda, R.: 1991, Freshwater Fishes of Sri Lanka, Wildlife Heritage Trust of Sri Lanka, pp. 229–236.Google Scholar
  23. Saenger, P., Hegerl, E.J. and Davie, J.D.S.: 1983, Global Status of Mangrove Ecosystems, Commission on Ecology Papers No. 3. The Environmentalist. Vol. 3.Google Scholar
  24. Scott, D.A.: 1989, A Directory of Asian Wetlands, IUCN, pp. 1–86.Google Scholar

Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • L.P. Jayatissa
    • 1
  • M.-C. Guero
    • 2
  • S. Hettiarachchi
    • 1
  • N. Koedam
    • 3
  1. 1.Department of BotanyUniversity of RuhunaMataraSri Lanka
  2. 2.French Institute of PondicherryPondicherryIndia
  3. 3.Laboratory of General Botany and Nature Management, Mangrove Management GroupVrije Universiteit BrusselBrusselBelgium

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