This book constitutes the post-conference proceedings of the First International Workshop on Discovering Drift Phenomena in Evolving Landscapes, DELTA 2024, held in Barcelona, Spain, on August 26, 2024. The 9 full papers presented together with 1 short paper were carefully reviewed and selected from 17 submissions. The papers are grouped into three topical sections, namely: adaptive and robust learning in dynamic environments; challenges and solutions in drift detection and anomaly explanation; and innovative approaches to concept drift detection and landscape shifts.