Hydroclimatic Trends and Solar Suitability in Semi-Arid Basins: A MCDM Approach in the Cheliff Basin, Algeria

Climate change drives the need for adaptive solar energy strategies. This study analyzes 41-year hydroclimatic trends (1985–2025) across the Cheliff River basin in Algeria using the Mann-Kendall test and Sen's slope estimator. It evaluates precipitation, temperature, relative humidity, and solar irradiance across 28 stations, integrating an objective CRITIC weighting approach with the TOPSIS multi-criteria decision-making framework to assess photovoltaic (PV) suitability.,Results reveal that 53.6% of stations exhibit significant upward solar irradiance trends (up to 0.94 MJ/m²/day), while 100% experience thermal intensification (temperatures rising up to 3.22°C in April) alongside stable precipitation. Furthermore, 32.1% show a significant decline in relative humidity (up to -11.38%). Comparing scenarios based on normal values versus trend-driven values via Sen's slope demonstrates that the latter yields higher, more contrasting performance peaks for both ground-mounted and floating photovoltaic (FPV) systems.,Deploying FPV systems offers a dual benefit for semi-arid basins: generating water-cooled clean energy while curbing reservoir evaporation to preserve scarce water resources, supporting sustainable agricultural and energy development.