Dr. Bellie Sivakumar is a professor at the Department of Civil Engineering of the Indian Institute of Technology Bombay (IIT Bombay), India. He received his Ph.D. degree (in Civil Engineering) from the National University of Singapore in 1999. He has about 25 years of experience in research, teaching, and professional services in the broader field of geosciences, especially in the fields of hydrology, hydroclimatology, and water resources. Sivakumar is an internationally recognised researcher for his enormous contributions and commanding role in advancing research in the areas of nonlinear dynamics, chaos, and complex network theories in Geosciences, with the development and applications of new scientific approaches and mathematical techniques. He has been a member of several professional societies, including AOGS, AGU, EGU, ASCE, IAHS, and MSSANZ. He has and continues to serve on many committees of professional societies and international conferences, including in AOGS, AGU, EGU, and MSSANZ. Sivakumar was the President of the Hydrological Sciences section of AOGS from 2016 to 2018 (and Vice-President from 2015–2016 and 2018–2019) and served as a secretary of the HS section during the period 2012–2014.