Ioannis Markonis conducts research on the hydrological cycle, climate variability, and extreme hydroclimatic events. His work focuses primarily on long-term changes in water availability, the relationships between climate change and hydrological extremes, and the statistical analysis of hydroclimatic data. His research involves collaboration on topics that integrate hydrology, climatology, under global warming. He is the author of numerous scientific publications, covering a wide range of topics such as drought, paleoclimatic changes, big data in geosciences, planetary water cycles, and terrestrial water cycle variability. His expertise provides valuable insights into the development of water resources under changing climatic conditions.