Multi-scale drivers of instream and riparian habitat integrity from stream power and landscape configuration in African catchments

• Multi-scale habitat integrity across Central, East, West, Southern African rivers. • Landscape configuration outperforms land cover in predicting habitat loss. • Distinguishes manageable human impacts from erosive stream power effects. • Identifies cumulative catchment as optimal scale for intervention planning. • Gradient dominance analysis enables targeted interventions in African watersheds. African instream and riparian ecosystems face intensifying pressure from multiple stressors, yet distinguishing human impacts from natural conditions remains challenging. This study evaluated how landscape configuration and stream power influence habitat integrity using the Index of Habitat Integrity (IHI) across 196 sites in seven African countries at six spatial scales (from cumulative basin to sub-basin riparian buffers). Generalised linear models showed contrasting stream power effects at the cumulative basin scale: maximum stream power significantly reduced the integrities of both habitat types, while minimum stream power enhanced riparian integrity. Generalised linear mixed effects models revealed that the cumulative basin scale was also optimal for predicting habitat integrity, with spatially aggregated settlements as the significant negative driver for both habitat types. Settlement spatial configuration (COHESION) emerged as the strongest predictor for both habitat types, with relative importance values exceeding those of proportional land cover metrics. Principal component analysis (PCA) revealed three orthogonal gradients driving dataset variation: anthropogenic pressure, vegetation patterns, and stream power dynamics, with both habitat types responding synchronously to anthropogenic pressure. Gradient Dominance Analysis using site scores from the PCA identified the dominant gradient at each site and project. Sites with high anthropogenic dominance showed the lowest integrity, while sites with high erosion exhibited degradation despite minimal human impact. Moderate dominance indicated greater habitat variability and higher integrity. This diagnostic approach complements the IHI, distinguishing anthropogenic impacts from natural drivers, enabling targeted interventions, and supporting evidence-based conservation in developing African watersheds.