Imperial College London's Water Systems Integration (WSI) Group, led by Professor Ana Mijic, is seeking highly motivated PhD candidates for projects in integrated water system modelling. The group has developed the WSIMOD framework, which enables flexible modelling of the terrestrial water cycle, including urban and rural interactions, natural processes, infrastructure, and human factors. Three PhD projects are available, each advancing key aspects of WSIMOD's development: P1: Modelling the whole-water cycle at a global scale using open-source datasets, focusing on water-system modelling, Python programming, and data assimilation. P2: Uncertainty assessment of integrated water system models, emphasizing uncertainty quantification, validation, and statistical analysis. P3: Development of LLM-based agents for hybrid water system modelling, combining machine learning, Python, and scenario analysis. Applicants must be UK Home students or of Chinese nationality, with a strong academic record (first-class degree or distinction), interest in water cycle modelling and management, and good programming skills (ideally Python). Relevant professional or research experience is valued. Candidates will apply for departmental PhD funding, with deadlines in January and March 2026. Funding details are not specified, but the positions are for funded PhD opportunities. To apply, email Professor Ana Mijic with your CV and a motivation paragraph for your chosen project. Internal interviews will be held until a suitable candidate is identified. Key research areas include integrated water system modelling, uncertainty quantification, machine learning, and the application of LLM agents in environmental science. The WSI Group offers a collaborative environment at Imperial College London, a leading institution in environmental and civil engineering research.