Drainage divide migration on the volcanic island of Madeira

Abstract

Drainage divide migration has emerged as a key process in understanding and predicting landscape evolution. In this study, we analyse the χ index on the volcanic island of Madeira to assess movement and stability of drainage divides. The index was calculated in MATLAB using elevation data from NASADEM. Results suggest that the central region of the island is relatively stable, whereas the flanks exhibit significant instability and divisor migration. Given the volcanic context, geology and uplift alone are unlikely to explain these anomalies. While the findings are consistent with previous studies for other Macaronesia Islands, more detailed analysis is required.