Dambos, seasonally saturated wetlands, are common in the headwaters of many
southern African rivers. It is widely believed that they play an important
role in regional hydrology. However, there have been very few studies of t
he natural processes occurring within catchments containing dambos, and the
ir hydrological functions are not well understood. This paper describes a s
tudy conducted to determine the water budget of a small Zimbabwean catchmen
t containing a single dambo. The results indicate that: a) rainfall dominat
es, and inflow from the surrounding catchment comprises only a small percen
tage (ca. 12%) of the total water input to the dambo; b) dry season flow is
typically only a small proportion (ca. 14%) of the water stored within the
dambo and potentially available to flow at the end of the wet season. Thes
e findings have important implications for agriculture and water resource m
anagement in the region; loss of water to evaporation rather than to river
flow indicates that water within some dambos could be put to productive use
in growing crops with little impact on dry season river flows. (C) 2000 El
sevier Science Ltd. All rights reserved.