Hydrological data, Nyong, Cameroon

This data set contains the data of water discharge (Q; m3/s). The timeframes available are as follows: from 1995 to 1999 for the Nsimi SEW spring; since 1991 for the Nsimi SEW outlet; and since 1998 for the large river sites (Messam, Pont So’o, Mbalmayo and Olama). Though the water discharge monitoring at the Nsimi outlet and at the large river sites is still going on, only water discharge data up to the year 2017 are available for download at the moment.

Methods: For each of the five sites of the network, the daily water discharge values are calculated from water levels (heights of water). At each site, the water level is monitored by both an automatic limnimeter (OTT Thalimede; 1-mm resolution) with a 10-min frequency and daily readings on limnimetric scales (staff gages) by local observers. The daily water discharge values for the four large river sites (Messam, Pont So’o, Mbalmayo and Olama) are subsequently computed using a rating curve (relationship between water level and discharge) for each site. Each rating curve is obtained from measurements of the average water velocity and the cross-sectional area. River gauging data on the Nyong River collected by the Hydrological Research Centre (CRH) of Yaounde since 1947 indicate good cross-sectional area stability. However, in order to account for riverbed morphology modification that could modify the rating curves, discharge measurements are periodically executed on each site by the CRH. At the Nsimi SEW, water discharge is computed using a rating curve obtained with a calibrated concrete weir installed at the watershed outlet.