Details of Award
NERC Reference : NER/B/S/2003/00771
Role of wetlands in ensuring water-security: an investigation of the source of dry-season streamflow augmentation by two contrasting dambos in Zambia
Grant Award
- Principal Investigator:
- Professor M New, University of Oxford, Geography - SoGE
- Co-Investigator:
- Professor WM Edmunds, University of Oxford, Geography - SoGE
- Grant held at:
- University of Oxford, Geography - SoGE
- Science Area:
- Terrestrial
- Freshwater
- Earth
- Atmospheric
- Overall Classification:
- Freshwater
- ENRIs:
- Natural Resource Management
- Science Topics:
- Earth Resources
- Hydrological Processes
- Hydrogeology
- Abstract:
- There is currently poor understanding of hydrological systems in the semi-arid and sub-humid African tropics. Dambos - shallow headwater wetlands common throughout Southern and Central Africa - are frequently described as sustaining dry-season streamflow through release of rainwater stored within the wetland ('sponge theory'), thereby ensuring water-security in a seasonally water-scarce environment. However, the hydrological functions of these wetlands are strongly debated: some recent studies suggest dambos do not augment downstream flow and, in fact, may lead to increased water losses from the system. The sources of dry-season streamflow originating from the wetland lie at the centre of this debate and, accordingly, form the focus of this study. We propose to use state-of-the-art isotopic (e.g. delta 18 O, delta 2H and 87Sr/86Sr)) and trace element (e.g. Cs, Li, F, U, Ba, Rb and Ba/Sr) approaches coupled with geochemical and hydrological mixing models (e.g. PHREEQC and EMMA) to differentiate the three end-members in dry-season flow from dambos: in-dambo water, shallow soil groundwater and deeper regolith/bedrock groundwater. Two catchments of similar size and vegetation characteristics but differing bedrock lithologies (crystalline vs carbonate-rich) in north-western Zambia will be studied. Streamflow at the wetland outflow will be sampled throughout the dry-season. Soil water will be collected through centrifugation of core samples collected along a circle around the wetland perimeter. Shallow groundwater will be sampled from piezometers installed along this circle and the deeper bedrock aquifer will be sampled from boreholes. Analyses will be conducted at Oxford University and the British Geological Survey in Wallingford.
- NERC Reference:
- NER/B/S/2003/00771
- Grant Stage:
- Completed
- Scheme:
- Small Grants Pre FEC
- Grant Status:
- Closed
- Programme:
- Small Grants
This grant award has a total value of £25,649
FDAB - Financial Details (Award breakdown by headings)
| Total - T&S | Total - Staff | Total - Other Costs | Total - Indirect Costs |
|---|---|---|---|
| £3,587 | £14,268 | £1,230 | £6,563 |
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