Abstract
In semi‐arid regions, small artificial surface reservoirs are important to meet the domestic and
agricultural water requirements of smallholder farmers. The research objective of the study was to
determine the rainfall‐runoff relation of two ungauged rivers using the measured water levels of the
downstream reservoir. The study areas are the catchments of the upper Mnyabezi River (22 km2) and
upper Bengu River (8 km2), which are tributaries of the Thuli River in southern Zimbabwe. The rainfallrunoff
relationship is established with the SCS‐Method. The catchments were each divided into subareas
by Thiessen‐polygons. For each polygon the amount of discharge was calculated based on the
precipitation, land use, land treatment, antecedent moisture conditions and hydrological soil group. The
summation of the calculated runoff per polygon formed the inflow variable for the reservoir models. The
collected daily water level data from the period March ‐May 2007 were used to calibrate the rainfallrunoff
model. The calibration process of the rainfall‐runoff model resulted in an initial abstraction of 7.6
% of the actual retention. It is concluded that the SCS‐method is a useful tool to simulate the rainfallrunoff
relation of small ungauged catchments
| Original language | Undefined |
|---|---|
| Title of host publication | Proceeedings 8th WaterNet/WARSFA/GWP-SA Symposium, 31 October - 2 November 2007, Lusaka, Zambia ( CD-ROM) |
| Place of Publication | Harare, Zimbabwe |
| Publisher | Waternet |
| Pages | - |
| Number of pages | 8 |
| Publication status | Published - 31 Oct 2007 |
Keywords
- IR-61523
- METIS-242775
Cite this
de Hamer, W., Love, D., Booij, M. J., & Hoekstra, A. Y. (2007). A rainfall-runoff model for two small ungauged catchment using the water balance of a reservoir for calibration. In Proceeedings 8th WaterNet/WARSFA/GWP-SA Symposium, 31 October - 2 November 2007, Lusaka, Zambia ( CD-ROM) (pp. -). Harare, Zimbabwe: Waternet.