Global climate change and high-intensity human activities present challenges for water resource and environmental management. The impacts of climate change and human activities on water resources include increased droughts and floods, reduced water availability, and harmful effects on ecosystems. In addition, accelerating global warming and increasing occurrence of extreme climate events drastically manipulate or even degrade the ecosystem services and functioning of large river basins, as well as urban areas. Water security has become a major challenge to the sustainable development of human society. Thus, it is of great significance to fully understand the response characteristics and mechanism of hydrological processes in the changing environment, to propose adaptive countermeasures such as water resources management, ecological environmental protection, and urban risk management, which will promote the sustainable development of human society and ecosystem.

In line with these objectives, the Scientific Committee of the XVIII World Water Resources Congress has approved three special sessions to be organised during the conference. These sessions, hosted by Academician of the Chinese Academy of Sciences, Professor Jun Xia, Fellow of the Norwegian Academy of Science and Letters, Professor Chong-Yu Xu, and Professor Lu Zhang from Wuhan University, will focus on the following themes: 'Smart Water Management in Large River Basins,' 'Characterising Hydrological Response in a Changing Environment,' and 'Hydro-meteorological Extremes and Urban Sustainable Development in a Changing Environment.'

We are honored to invite Former President of IAHS Professor Kuniyoshi Takeuchi, Former President of IWRA Professor Cecilia Tortajada, and several academicians from various countries including Professor Asit K Biswas at the University of Glasgow, Professor Lars Gottschalk at the University of Oslo, Professor Slobodan P. Simonovic at the University of Western Ontario, Professor Bridget Scanlon at the University of Texas at Austin, Professor Rob Vertessy at the University of Melbourne, and Professor Ian White at the Australian National University, as well as many international and domestic famous scholars, to share the academic frontiers of the relevant research fields together.

We warmly welcome scholars engaged in these research areas to share their findings and contribute to these enlightening sessions.