Hydropluviometric variability in a forest watershed undergoing accelerated urbanization: the case of Mefou (South Cameroon)

Abstract

Abstract This article has as objective to investigate the impact of rainfall variability and land use changes on river discharge in the Mefou basin over the recent period (1963–2018). To achieve this goal, hydrometeorological data of this basin were analyzed using the Pettitt test. Likewise, land use changes were also analyzed using supervised classifications of Landsat satellite images at two periods (1973 and 2018). Average and extreme flows of Mefou river have increased since 1985-86, unlike the rainfall, which generally decreased for all seasons from the 1970s, apart from summer, where the reverse was observed. Changes in land use (increase impervious areas and a decrease in forest and water bodies) seem to be the main cause of the increase in runoff observed. The rainfall plays an essentially amplifying role in the increase in discharge in the seasons during which they occur. Those having experienced an increase or a maintenance of rainfall (summer and spring) recorded the most significant increases in discharges. These results could be useful for the improvement of future simulations of the Mefou river flow and the prevention of socio-environmental disasters like floods in the basin.