The estimation of the catchment runoff using a small number of rainfall stations in Burkina Faso
AbstractThe objective of this study was to determine a suitable method to compute the runoff over a catchment with a few number of rainfall stations. Input hydrological variables were calculated against varying rainfall events duration bounded by at least one no-rainy day.
The study shows that it is possible to estimate correctly the runoff over a catchment of about 500 km2, by using the mean rainfall of Thiessen, the antecedent precipitation index and the cumulative rainfall since the start of the rainy season. The accuracy of the method increases when the rainfall stations are uniformly distributed within the catchment.
This work must be done by separating the heavy rainfall events (≥ 40 mm) into two parts: events of the beginning and events of the middle of the rainy season, in order to indirectly take into account the rainfall intensity. The model was applied to the Mogtedo irrigation scheme (Central region of Burkina Faso).
Key Words: Catchment-Rainfall-Runoff-Antecedent precipitation index-Multiple regression.
Journal of Environmental Extension Vol.4 2003: 67-73