Is Climate or Direct Human Influence Responsible for Discharge Decrease in the Tunisian Merguellil Basin?

Climate change and direct anthropogenic impact are recognized as two major factors affecting catchment runoff. This study investigated the separate effect of each these for runoff from important Tunisian Merguellil catchment. For this purpose, more than forty years hydrological data were used. The methodology was based on characterization, NDVI index to monitor land use dynamics, Budyko approach specify origin change. results show that is much upstream downstream. last three decades display a 40% reduction in associated with influence humans, who responsible about 78% variation flow. It appears climate contributes less 22%. combination increased cultivated decreased annual rainfall main reason reduced Consequently, effects threaten sustainable runoff, water reservoirs, future supply general. Ultimately, available remains an parameter key indicator guide choices decision-makers practitioners current climatic conditions. supporting management remaining resources.