Methodology to detect long-term trends in groundwater by monitoring changes in vegetation distribution

Abstract

Multidate remotely sensed images, covering a period of 34 years (1967–2001), have been used to detect long-term trends in groundwater resources around Lake Ngami in the distal reaches of Botswana's Okavango Delta. The detection methodology is based on monitoring changes in the vegetation distribution of the studied area. The changes consist of sustained shifts from perennial wetland to an intermittently flooded dryland and a significant increase in woody species adapted to low water table conditions (e.g. Acacia mellifera and Acacia erioloba).

Acknowledgements

Work leading to this article was co-funded by START International, Canon Collins Educational Trust for Southern Africa, the Southern Africa Science Regional Initiative and the Harry Oppenheimer Okavango Research Centre through Professor H. Annergan and Professor S. Ringrose. Sincere thanks go to the anonymous reviewers for their instructive comments and to D.R. Zinhumwe for encouragement during the compilation of this article.

Notes

^†This remark is reported in Brind (1955). Although Livingstone (a missionary explorer who travelled extensively in Africa during the 19th century) did not publish anything himself, his diaries have been published widely (see, e.g. Ransford 1978 and Livingstone 1858).