The sustainable development of groundwater resources in arid and semi-arid regions is a challenging task hindered by climate change and human activities. The rational utilization and management of groundwater resources is, therefore, dependent on an understanding of the influences of human and climatic factors on the spatial distribution of groundwater resources and their change over time. The thick Quaternary aquifers in the Yinchuan Basin, China were used herein as an example of how to quantitatively assess spatial and temporal trends in groundwater resources in response to human activities and climate change. A 3D transient groundwater flow model was constructed and used to simulate the evolution and spatial variability of hydrogeological processes from 1990 to 2020. By subsequently applying regime shift detection and correlation analysis to the simulation results, we found that: 1) groundwater storage was continuously depleted over the 30-year period, reaching a cumulative depletion of 1.89×10⁹ m³; 2) human activities were mainly responsible for variations in regional hydrogeological processes for a period of up to 30 years. Climate only affected short-term interannual fluctuations in groundwater storage; 3) human activities (e.g., river water diversion and groundwater abstractions) were the decisive factors causing a continuous reduction of groundwater resources. A policy-driven reduction in water diversion from the Yellow River directly led to a significant drop in groundwater storage, which had a consequent effect on surface water and groundwater interactions and altered agricultural irrigation patterns (crop patterns and irrigation methods); 4) the amount of groundwater recharge from the Yellow River and local lakes increased from 1990 to 2020, whereas the discharge of groundwater to the Yellow River and lakes decreased.

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With the growth of global population, the big cities become increasingly crowded. It is not rare to see large crowds in public transportations and events with masses of visitors, such as music festivals and football matches. The question “How to deal with crowds” is receiving attention, both from academia and practical crowd management. This thesis aims at contributing to a better understanding of crowds from the perspective of individual crowd members’ experiences, including their well- being, emotional experiences and action tendencies. In addition, we want to understand the emotional contagion effect between groups in crowds. To achieve this, we chose to go into the crowds, get in touch with the crowd members, and try to find out what factors sustain their well-being, how their emotional experiences can be measured in a playful and non-intrusive manner, what they tend to do when they have certain emotions, and how the grouping behavior reflects their experiences.@en

Recent accidents (News, 2006, 2010, 2013, 2015) show that crowded events can quickly turn into tragedies. The goal of crowd management is to avoid such accidents through careful planning and implementation. Crowd management practices are collaborative efforts between the different actors of the crowd management team and the crowd that depend on effective handling, sharing, and communication of information. Safety and comfort of a crowd depend on the success of such efforts. We have studied current practices and the role of technology through interviews to crowd managers. Our findings show that event planning and monitoring can be complex and sophisticated, but are operated with little support from technology. Crowd managers intend to increase their use of technology, but they have been so far dissatisfied by existing solutions. We provide recommendations for a bigger role of technology in crowd management.

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Of the many crowd behavior models, very few have been used in assisting crowd management practice. This lack of usage is partly due to crowd management involving a diversity of situations that require competencies in observing, sense-making, anticipating and acting. Crowd research is similarly scattered across disciplines and needs integration to advance the field towards supporting practice. To address these needs, we present inCrowd, an integrated framework detailing a high-level architecture of a decision-support system for crowd management and model development. It also offers a lens for categorizing crowd literature, allowing us to present a structured literature review.@en