Abstract:The high degree of spatial variability in climate conditions, and a lack of meteorological data for East Asia, present challenges to conducting surface water research in the context of the hydrological cycle. In addition, East Asia is facing pressure from both water resource scarcity and water pollution. The consequences of water pollution have attracted public concern in recent years. The low frequency and difficulty of monitoring water quality present challenges to understanding the continuous spatial distributions of non-point source pollution mechanisms in East Asia. The China Meteorological Assimilation Driving Datasets for the Soil and Water Assessment Tool (SWAT) model (CMADS) was developed to provide high-resolution, high-quality meteorological data for use by the scientific community. Applying CMADS can significantly reduce the meteorological input uncertainty and improve the performance of non-point source pollution models, since water resources and non-point source pollution can be more accurately localised. In addition, researchers can make use of high-resolution time series data from CMADS to conduct spatial-and temporal-scale analyses of meteorological data. This Special Issue, "Application of the China Meteorological Assimilation Driving Datasets for the SWAT Model (CMADS) in East Asia", provides a platform to introduce recent advances in the modelling of water quality and quantity in watersheds using CMADS and hydrological models, and underscores its application to a wide range of topics.Keywords: East Asia; CMADS; meteorological input uncertainty; hydrological modelling; SWAT; non-point source pollution models China and the surrounding region in East Asia are considered to be the birthplace of human civilisation. East Asia experiences the most typical and pronounced monsoon climate in the world, and detailed analyses of the atmospheric hydrological cycle in East Asia can offer a substantial regional contribution to global climate change research.Travelling back to the 19th century, natural science research in East Asia, and even globally, still followed the paradigm of dividing the whole into smaller components (e.g., dividing systems into elements), and then studying each isolated part individually. In this context, there was no interdisciplinary approach for researching various types of scientific issues simultaneously. By the second half of the 20th century, a highly detailed and complex classification of numerous natural science disciplines had been developed, and scientists were accustomed to dividing scientific fields into a number of sub-fields. This promoted a more professional approach to research and led to the evolution of various cross-disciplines and interdisciplinary disciplines. However, in recent decades, scientists have recognised many problems associated with the single-disciplinary approach of the 19th century. More researchers reconsidered methods for systematically considering and analysing different system elements of multiple disciplines at a more comprehensive le...