The Evolution and Frontiers of Groundwater Research Hotspots in China

Groundwater plays an irreplaceable role in maintaining ecosystem stability and supporting production and daily life. Its extensive and long-term development and utilization have attracted increasing academic attention to groundwater research. In this study, we employed bibliometric analysis of 3514 graduate dissertations published between 1988 and 2024, extracted from the China National Knowledge Infrastructure (CNKI), examining their quantitative output, institutional affiliations, research fields, and keywords to explore groundwater research trends. The analysis indicates a growing focus on groundwater research, with 1066 (30%) graduate dissertations published in the past 5 years. North China, East China, and Northwest China were identified as the primary regions hosting groundwater research institutions. As a typical interdisciplinary field, "Earth Sciences," "Industrial Technology," and "Environmental Science" emerged as active intersecting disciplines. Moreover, keywords such as "numerical simulation," "hydrochemical characteristics," and "isotopes" were identified as high-frequency terms. Despite some progress, groundwater research continues to face challenges in several areas, including but not limited to the characterization of complex media, the integration of multi-source data, and the understanding of hydrogeochemical mechanisms. Based on keyword co-occurrence network and burst analysis, we predict future primary research directions. The integration of traditional disciplines such as hydrology, biology, and geochemistry is becoming increasingly prominent, while convergence with emerging fields like machine learning, big data, and artificial intelligence represents a frontier trend. The combined application of multiple technologies is becoming the optimal choice for addressing complex groundwater issues. In summary, this study provides a new perspective and offers broader insights for the research and development in the field of groundwater.