A three month stream flow forecast for water management in the upper Olifants catchment

[摘要] English: A Climate Predictability Tool was used to evaluate the relationship between sea-surfacetemperatures and stream flow at different lead-times in the upper Olifants catchment inMpumalanga, South Africa. Four stream flow stations were selected from each of the subcatchmentsof the upper Olifants, namely the Groot Olifants on the eastern side and theWilger on the western side of the catchment.Canonical correlation analyses were used to make three month stream flow forecasts forOctober-November-December (OND) and January-February-March (JFM) seasons.Monthly global-scale SSTs were used to evaluate the effect of lead-times on correlationsbetween global Sea-Surface Temperatures (SSTs) and stream flow. Then the lead-timeswith Pearson's correlation values greater than 0.50 were selected to be used for evaluatingpossible origins of stream flow forecasting skill in the Equatorial Atlantic, SouthernAtlantic, Equatorial Indian and Pacific Oceans.Although local climatic and hydrological characteristics were not considered in this studygood hit score skill from the Southern Atlantic Ocean was found at a short lead-time oftwo months for both OND and JFM seasons. The equatorial Atlantic Ocean gave a goodhit skill score at longer lead-times of seven and eight months. The equatorial Indian Oceangave a higher Heidke score at a short lead-time of two months during OND and JFMseasons in the Groot Olifants sub-catchment. The oceanic domains adjacent to the southernAfrican subcontinent gave a good Heidke score at a shorter lead-time as compared to theequatorial Pacific Ocean. These forecasts could be used for planning water storage andreleases in dams that are down stream of these stream flow monitoring points.

[发布机构] University of the Free State