Examples of design of HFS in WMO-assisted projects

Abstract

This system was designed in 1969 and commissioned in 1974. The rivers concerned were the Niger itself from its source to its confluence with the River Bani in Mali, and its main tributaries, the Milo and Tinkisso in Guinea and the Sankarani and Bani in Mali. A total of 77 hydrometric and rainfall stations were taken over by the project and available for the calibration of the forecasting models. At the beginning of the project, 12 stations were equipped with radio-transmitters and could be used for real-time data transmission, and thus for operational forecasts. The size of the basin and its physiography, consisting of the high mountains of Fouta Djallon in the upper reaches of the rivers and of flat valleys entering the arid plain of the middle reach after the confluence of the Niger with the Bani (the inner delta of the Niger), required more detailed real-time information on the flows and rainfall. For this reason 15 additional radio stations were established, each to transmit both rainfall and discharge data daily during the rainy and flood season, including the period of flood recession. The total of 27 radio stations were installed so that each larger tributary could be monitored by a discharge station, either before or after its confluence with a river of second or first order (Niger).