Hydroclimatic Variability, Change Points and Drought Characteristics in the Upper and Middle Cheliff Basin, Algeria: A Multi-Station Analysis

This research examines the hydroclimatic variability of precipitation in part of the Cheliff Basin, the largest basin in northern Algeria, over the period 1971–2016. The dataset consists of records from 17 rainfall stations located within the Upper and Middle Cheliff watershed, selected for their representativeness of the different hydrographic units and provided by the National Agency for Hydraulic Resources (ANRH). The time series were analyzed using a seven-year moving average to smooth interannual fluctuations and subsequently subjected to the non-parametric Pettitt and Mann–Kendall tests to detect change points and identify significant trends. The results reveal an alternation between wet periods (1972–1978) and dry periods (1979–2001 and 2005–2006) in 12 out of the 17 stations. Major breakpoints are primarily observed between the late 1970s and the mid-1980s. Seven stations exhibit a relatively stable rainfall regime, whereas the remaining ten record precipitation deficits ranging from 5% to 53%, reflecting the pronounced impact of prolonged droughts across the basin. These findings confirm the intensification of water deficit conditions and highlight the increasing vulnerability of the Cheliff Basin to climate change. They underscore the necessity of integrating hydroclimatic variability into water resource planning and sustainable management strategies in order to enhance the resilience of hydrological systems and ensure secure water supply for agricultural, industrial, and domestic uses.