Changes in rivers generally result from interactions between climate variability/change and anthropization (Orr and Carling, 2006). It is however, recognized that their sensitivity to these factors also depends on the natural predispositions (size, slope system, type of soil, etc.) of their watersheds (Gibson et., 2005).
Most of time, changes in hydrological regimes are only examined through rainfall-discharges relationships (Liénou et al., 2008; Ebodé et al., 2021a). Few authors in sub-Saharan Africa for example (D'Orgeval and Polcher, 2008; Amogu et al., 2010; Ebodé et al., 2021b) have assessed the hydrological impacts of human-induced environmental changes. Likewise, studies that attempted to dissociate the latter from those arising from exclusively hydro-climatic fluctuations are quantitatively limited (Ebodé et al., 2020; Ebodé et al., 2022a; Ebodé et al., 2022b; Ebodé 2022a; Ebodé, 2022b; Ebodé, 2022c). However, there is no doubt that anthropogenic actions through urbanization and industrial agriculture, which have resulted in large-scale deforestation, have increased considerably over the past thirty years throughout Sub-Saharan Africa and even beyond.
Beyond the climate change that is currently raging throughout Cameroun and Central Africa (Ebodé et al., 2020; Ebodé, 2022c), the studied basin (Mefou) has experienced accelerated and uncontrolled urbanization through an excessive spatial extension of the Yaounde city (Ebodé, 2022d; Ebodé, 2022e), whose population has multiplied by 10 in about thirty years, from 50 000 in 1957 to 1 500 000 in 2008. Today it is estimated at 2 500 000 inhabitants. Projections predict that it will exceed 3 000 000 by 2030 (BUCREP, 2010). This population growth which has as corollary the increase in impervious areas, has probably caused a change in the rainfall-runoff relationship, which requires a new study of hydrological variability.
The main objective of this study is to investigate the impact of precipitation variability and land use change on the hydrological dynamics of the Mefou river. Considering that few studies have attempted to investigate the impact of rainfall variability and land use change on river regimes in Central Africa, this paper contributes to this debate by focusing our analysis on the Mefou river basin in South Cameroon, which is representative of Central African basins under the sub-equatorial Atlantic climate. It appears fundamental for this basin where many socio-environmental problems are observed, in this case, floods. In addition, the data and new entrants would help in the long-term planning of water demand and use as well as improve future simulations of the flow river.