**About the Special Issue Editor**

**Arjen Y. Hoekstra†** (1967–2019) was Professor in Water Management at the University of Twente, and Visiting Professor at the Lee Kuan Yew School of Public Policy at the National University of Singapore. He held an M.S. degree in Civil Engineering and a Ph.D. degree in Policy Analysis, both from Delft University of Technology. Hoekstra has led a variety of interdisciplinary research projects and advised governments, civil society organizations, companies, and multilateral institutions like UNESCO and the World Bank. Hoekstra has received various awards, including an ERC Advanced Grant, Europe's most prestigious research grant.

Hoekstra pioneered in quantifying the water volumes virtually embedded in trade, thus showing the relevance of a global perspective on water use and scarcity. As creator of the water footprint concept, Hoekstra introduced supply chain thinking in water management. With the development of Water Footprint Assessment, he laid the foundation of a new interdisciplinary research field, addressing the relations between water management, consumption and trade. Hoekstra was founder of the Water Footprint Network (2008), co-initiator of the Water Footprint Research Alliance (2015), and founding member of the Planetary Accounting Network (2018).

Hoekstra's scientific publications cover a wide range of topics related to water, food, energy, and trade, and include a large number of highly cited articles and book chapters. His books have been translated into several languages and include The Water Footprint of Modern Consumer Society (Routledge, 2013, 2019), The Water Footprint Assessment Manual (Earthscan, 2011), and Globalization of Water (Wiley-Blackwell, 2008). Hoekstra was Editor-in-Chief of *Water*, an interdisciplinary open access journal covering all aspects of water, including water science, technology, management, and governance.

Hoekstra has taught in a variety of subjects, including, sustainable development, water management, river basin management, hydrology, water quality, water footprint assessment, natural resources valuation, environmental systems analysis, and policy analysis. He developed various educational tools, including the River Basin Game and the Globalization of Water Role Play.

His colleagues will miss himas a passionate human, always working and socially engaged. He had an open mind, was intrigued by other cultures, and visited many countries over the years. To-the-point, no-nonsense, and starting from a base of trust characterized Arjen. He enjoyed giving autonomy to the people he with whom he worked. He was socially active in our team and was working from his sustainable office, a green oasis filled with plants. He was an inspiration to us all.
