ABSTRACT Oxbow lakes are abandoned channels formed by lateral erosion and natural river cutoff, serving as important wetland resources for regional ecosystem balance. However, the long-term spatiotemporal evolution and hydrological mechanisms of oxbow lakes remain poorly understood. In this study, multi-temporal Landsat images were used to derive Water Appearance Frequency (WAF), from which river centerlines and morphological characteristics were extracted. Key hydrological driving factors were identified by integrating hydrometeorological data. The Mann–Kendall test and the Hurst index were applied to analyze trends and abrupt changes. Using these methods to study the inundation and morphological changes of oxbow lakes and mainstream evolutionary patterns and dynamic mechanisms. The results indicated significant spatial and temporal variations in inundation frequency, with high-frequency zones delineating the river morphology. After the completion of the Three Gorges Dam, the area of low-frequency inundation increased, whereas the extent and width of high-frequency inundation zones and the overall river area decreased, indicating wetland degradation. Morphological mutations during the dry season corresponded to dam operations, while those during the flood season coincided with extreme climatic events. These findings enhance understanding of the long-term evolution and driving mechanisms of oxbow lakes and provide scientific support for floodplain wetland restoration and river management.
Liu et al. (Mon,) studied this question.