More information:

Hamandawana, H. 2008. Monitoring transitions in vegetation cover to detect long-term trends in ground water resources. 2008 UNESCO UCI Groundwater Conference Proceedings

Description:

Monitoring transitions in vegetation cover to detect long-term trends in ground water resources.

Summary / Notes:

This paper provides a simple methodology to detect long-term trends in groundwater resources by using multi-date remotely sensed imagery and in-situ observations to monitor transitions inrnvegetation in and around Lake Ngami's emergent floodplain environment in the distal reaches of Botswana's Okavango Delta. Covering a period of 34 years between 1967 and 2001, trendsrnemerging from this reconstruction point to a sustained shift from a perennial wetland to an intermittently flooded dryland environment, significant increase in drought tolerant woodyrnspecies notably Acacia mellifera and Acacia erioloba, and sustained contraction of groundwater resources. With transitions in the distribution of these and other indicator species mimicking changes in hydrological conditions, it is apparent that spatial and temporal variations in their distribution can be used to provide long-term trends in groundwater resources. In view of the general lack of time-series data on regional trends in aquifer storages in arid and semi-arid areas, remote-sensing-based monitoring of vegetation can be exploited to provide proxy measurements and useful insights that can be used to guide the formulation of informed interventions potentially capable of enhancing our capacities to cope with decreasing supplies in areas where signals of climate change point to the inevitability of increased scarcities. Key words: groundwater, long-term trends, remote sensing, arid/semi arid areas, drying sequences.

Year: 2008

Type: Report

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