Interannual runoff persistence and climate sensitivity in contrasting karst and non-karst semi-arid catchments

Subsurface storage may influence how semi-arid catchments integrate hydroclimatic variability. We compared annual runoff in karstic Sebdou (1973–2006; n = 33 hydrological years) and non-karstic marl–clay Batna (discharge: 1969–1986, n = 17; PET: 1973–2006, n = 34 calendar years; concurrent P–Q–PET analysis: 1973–1974 to 1985–1986, n = 13). Mann–Kendall trends, precipitation–runoff elasticity, annual Budyko diagnostics, and runoff autocorrelation were applied. Sebdou showed declining runoff, increasing temperature-derived PET, elasticity of 1.19, and lag-1 runoff autocorrelation of 0.67. Batna showed a lower lag-1 estimate (0.38), no detectable precipitation–runoff elasticity, and increasing temperature-derived PET. These patterns suggest contrasting annual hydrological behaviour consistent with different subsurface settings. However, unequal record lengths, unquantified annual storage changes, and other catchment controls preclude unique attribution to geology.