Study and analysis of the streamflow decline in North Algeria

Abstract

This research analyses the variability of hydrometeorology data in the Sebaou watershed, (Northern Algeria) and examines the impacts of Climate Change (CC) and Human Activities (HA) on the streamflow decrease, using the climate elasticity model and hydrologic modelling. The results of tests, used to identify the trends and breakpoints in the data series, show significant downward trends and breakpoints, through the 1980s in streamflow. At the Sebaou outlet, the decrease of runoff, after 1985 is assessed; 34.8%, 35.8%, 28.5%, 41.6% and 40.1% in year, autumn, winter, spring and summer, respectively. The results obtained, by climate elasticity model, reveal that a 10% change in rainfall ensues in around 16–25% variation in streamflow. Besides the factors (CC and HA) have an effect of 58% and 42% respectively, on the reduction of streamflow in the Sebaou. The land use maps analysis approve those of the elasticity method and the GR2M model.