The Hydrosphere in Crisis: Human Impact, Climate Change, and Pathways to Resilience, 2nd Edition

Dear Colleagues,

Our planet is currently undergoing unprecedented, rapid, and drastic changes driven by human activities and the climate system. These changes have far-reaching implications across various components of the Earth system, posing a significant threat to human survival. Among all Earth system spheres, the hydrosphere is fundamental to the existence of nearly all life on Earth, the maintenance of the life-sustaining eco-environment, and the development of human society. The history of human development can be seen as a journey of water exploration, management, and utilization. At the same time, the hydrosphere is the most sensitive sphere to external changes. Over the past few hundred years, the rapid development of human society has severely compromised the quantity and quality of water resources. In addition to human-induced factors, climate warming is widely recognized as the most extensive and profound factor affecting the global state of the hydrosphere and water resource availability. It is not an overstatement to say that the Earth's hydrosphere is under immense pressure from human society and global warming, undergoing unprecedented transformations. As a result, water crises and water-related geohazards are becoming increasingly frequent. Given these challenges, we have launched this topic on the hydrosphere to gather the latest and most innovative insights into its current status, its evolution driven by anthropogenic activities and climate warming, and the corresponding strategies, policies, and technologies needed to address these issues.

The first edition of the Topic titled “Hydrosphere Under the Driving of Human Activity and Climate Change: Status, Evolution and Strategies” was highly successful. It significantly advanced our understanding of hydrological systems across continental to coastal environments, with a focus on hydrogeochemical processes, human impacts, and resource sustainability.

This second edition titled “The Hydrosphere in Crisis: Human Impact, Climate Change, and Pathways to Resilience, 2nd Edition” aims to build on the success of the first by delving deeper into emerging challenges, such as the intensifying impacts of extreme weather events on water systems. It also explores novel research directions, including the integration of advanced digital technologies in hydrological monitoring, and recent technological and policy developments, like the adoption of innovative water treatment technologies and new governance frameworks for transboundary water resources. The aims of this new editon are to collect the latest and most innovative insights into the current state of the hydrosphere, its evolution influenced by anthropogenic activities and climate warming, and to explore corresponding strategies, policies, and technologies for resilience.

We encourage submissions of various manuscript types, including Review Articles, Perspective Papers, Innovative Case Studies, Original Research, and Short Communications. Potential topics include, but are not limited to, the following:

• Surface and subsurface water circulation;
• Surface water and groundwater interaction;
• Water resource sustainable development;
• Hydrochemistry formation and water quality assessment;
• Geothermal water genesis and development;
• Water behaviors and related geohazards;
• Nature-based Solutions for water management;
• Water resource management and policy;
• Water knowledge dissemination;
• Hydrosphere digitalization;
• Artificial Intelligence in water resource research and management;
• Machine Learning in hydrological studies;
• Water-Energy-Food Nexus under climate stress;
• Water governance;
• Socio-economic impacts;
• Resilience strategies.

We look forward to your valuable contributions to this important topic.

Dr. Yong Xiao
Prof. Dr. Jinlong Zhou
Dr. Qichen Hao
Dr. Jibin Han
Dr. Wanjun Jiang
Topic Editors