Journal article
The role of a dambo in the hydrology of a catchment and the river network downstream
- Abstract:
- Dambos are shallow, seasonally inundated wetlands and are a widespread landform in Central and Southern Africa. Owing to their importance in local agriculture and as a water resource, the hydrology of dambos is of considerable interest: varied, and sometimes contradictory, hydrological characteristics have been described in the literature. The issues in contention focus on the role of the dambo in (i) the catchment evapotranspiration (ET) budget, (ii) flood flow retardation and attenuation, and (iii) sustaining dry season flow to the river down-stream. In addition, both rainfall and groundwater have been identified as the dominant source of water to the dambo and various hydrogeological models have been proposed to describe the hydrological functions of the landform. In this paper, hydrological and geochemical data collected over a full hydrological year are used to investigate and describe the hydrological functions of a dambo in north-western Zambia. The Penman estimate of wetland ET was less than the ET for the miombo-wooded interfluve and the wetland has been shown to have little effect on flood flow retardation or attenuation. Discharge of water within the wetland contributed little to the dry season flow from the dambo, which was sustained primarily by groundwater discharge. Flow in a perched aquifer within the catchment coils contributed to a large portion of baseflow during the rains and early dry season. This source ceased by the mid dry season, implying that the sustained middle to late dry season streamflow from the wetland is through discharge of a deeper aquifer within the underlying regolith or bedrock. This hypothesis is tested through an analysis of groundwater and wetland geochemistry. Various physical parameters, PHREEQC model results and end member mixing analysis (EMMA) suggest strongly that the deep Upper Roan dolomite aquifer is the source of sustained discharge from the wetland.
- Publication status:
- Published
- Peer review status:
- Peer reviewed
Actions
- Publisher:
- Copernicus Publications
- Journal:
- Hydrology and Earth System Sciences More from this journal
- Volume:
- 7
- Issue:
- 3
- Pages:
- 339-357
- Publication date:
- 2003-01-01
- DOI:
- EISSN:
-
1607-7938
- ISSN:
-
1027-5606
- Language:
-
English
- Keywords:
- Subjects:
- UUID:
-
uuid:ed52025a-0591-48d0-a326-cd6198e0cbc2
- Local pid:
-
ora:5492
- Deposit date:
-
2011-06-23
Terms of use
- Copyright holder:
- C J von der Heyden & M G New
- Copyright date:
- 2003
- Notes:
- Citation: von der Heyden, C. J. & New, M. G. (2003). 'The role of a dambo in the hydrology of a catchment and the river network downstream', Hydrology and Earth System Sciences 7(3), 339-357. © Authors 2003. This article is distributed under the terms of the Creative Commons Attribution, NonCommercial and ShareAlike License (http://creativecommons.org/licenses/by-nc-sa/2.0/deed.en). This permits the copying and distribution of the work, and the making of derivative works, provided the original authors are credited. However, you may not use this work for commercial purposes, and if you alter, transform, or build upon this work, you must distribute the resulting work under a license identical to this one. For any reuse or distribution, you must make clear to others the license terms of this work. These conditions may be waived if you get permission from the copyright holder and, in the case of commercial use during the first five years, you also get permission from Copernicus Publications and the European Geosciences Union.
If you are the owner of this record, you can report an update to it here: Report update to this record