Andrea Rinaldo is not only a brilliant scientist but a thoughtful and methodical researcher who has generously served academia, the science communities and society. His groundbreaking contributions to water science have changed the way we see and understand the water-environment-health nexus. He is a founder of and a world leader in the interdisciplinary field connecting ecology, hydrology and epidemiology. His work has far-reaching implications for our understanding of ecosystems and water-based diseases, with an outsized impact on society, and developing countries in particular, by improving the way we manage water resources and risks associated with waterborne diseases while balancing environmental and health implications. Andrea was the originator of many of the ideas that define modern geomorphology, and he has generated a large and novel body of theory, marking a turning point in the field, which continues to be highly referenced in the study of geomorphology today.

Andrea embodies the hallmarks of a Robert E. Horton Medal recipient: His life’s work is marked by scientific excellence and impact, and he is world-renowned in his field. Andrea has also been of service to the field as a journal editor, a member of AGU and other professional society committees, and an adviser for governments and policymakers on water-related problems. Notably, he played an important role in the study of the high waters in the city of Venice. For decades, Andrea organized summer schools at the Istituto Veneto in Venice, which provides junior scholars and doctoral students with the opportunity to interact with leading water scientists and ecologists from around the world. Through these short courses and workshops, he stimulated learning and discovery for new generations of water scientists. With his enthusiasm and positive demeanor, he has educated many scientists who have pursued their own successful careers. He has been a champion of equity in the field and an ardent promoter and supporter of women in academia and scholars from underserved backgrounds.

Andrea is a unique researcher in that he approaches his work with unparalleled creativity, intensity and enthusiasm. His contributions have deeply impacted the study and our understanding of water science, and he has distinguished himself with ideas that have had and will continue to have long-lasting implications for broad and diverse fields of science. His contributions have opened new avenues of discovery, which others have actively followed, but Andrea is and will continue to be a world leader in his field.

— Marc Parlange
The University of Rhode Island
Kingston, Rhode Island

Thank you, Marc, for your generous citation; I fear that our friendship biased your judgement. Nonetheless, I am delighted to accept the 2023 Horton Medal, humbled and proud of following in the steps of many of my scientific heroes. Hydrology is rapidly changing its aims and tools, in particular by focusing on water controls on living organisms and communities, as foreseen by giants of the field decades ago. Will future large-scale water resources management plans include the reduction of the loss of biodiversity? Is the structure of river networks a template of the spread of waterborne diseases? Will we be able to prevent water resources development schemes in the light of the social and economic cost of the increased burden of poverty-reinforcing disease they would bring? How nature works matters as well: when the substrate for ecological interactions is the river basin, its emerging universality of form — the legacy of a self-organized critical nature — spills onto its function as ecological corridors for species, populations, pathogens. New questions and deeper understanding thus resonate, enabling a paradigm shift in the quantification of the water-related natural capital, underpinning that the fundamental study in searching for historical causes is hydrography (as Bertrand Russell wrote in 1934). Big or small, our accomplishments/discoveries talk about a journey, whose outcome was far from obvious, accompanied by students, colleagues and institutions. My gratitude, and sour regret for his loss, goes to Ignacio Rodriguez-Iturbe, master of contemporary thought, dearest friend and role model with whom I worked for more than 30 years. I have also been blessed by exceptional students, many now colleagues, whom I am ideally hugging. Colleagues influenced me deeply in different ways, like Gedeon Dagan or Marc Parlange and Patrick Aebischer, who hired me at École Polytechnique Fédérale de Lausanne (EPFL). My ties to the University of Padua are profound, where the influence of Claudio Datei and Giovanni Marchesini, whose memory I cherish, digs deep still. The fertile intellectual environment where I grew up in Venice I shared with my brothers, Piero and Daniele. Key, however, has been the impact of what EPFL gave me 17 years ago, a unique research infrastructure for integrated laboratory, field and theoretical studies focused on hydrologic controls on living communities. Rock-solid support from a wonderful family made the rest: my wife of 43 years, Caterina (my hero); Daniele, Carlotta and Tobia, with their families; and my grandchildren, Mario and Adriana. — Andrea Rinaldo, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland Università di Padova, Padua, Italy