Study on the spatiotemporal distribution characteristics and influencing factors of open water during the freezing period in the Inner Mongolia Section of the Yellow River from 1986 to 2023

The Inner Mongolia section of the Yellow River, northern China This study utilizes Landsat remote sensing data from 1986 to 2023 and a random forest algorithm to analyze the spatiotemporal distribution characteristics of open water during the winter freezing period. The focus is on the correlation between open water area and air temperature and water discharge, the relationship between open water distribution and the geometric characteristics of river bends, and the connection between open water and ice jam formation. The results reveal significant differences in the frequency of open water occurrences across various river sections, with reservoir construction and operation playing a key role in altering these distribution patterns. The open water area shows a moderate positive correlation with water discharge and a weaker correlation with air temperature, highlighting the critical role of water discharge in its formation. Additionally, the spatial pattern of open water downstream and ice jams near bend apexes suggests a potential indicator for identifying ice jam-prone areas. These findings enhance the understanding of winter hydrological processes in this region and provide useful indicators for assessing and managing ice flood hazards in the Yellow River Basin. • Open water during freezing period was mapped using Landsat data and random forest. • Open water occurs frequently at river bends and downstream of reservoirs. • Discharge strongly influences open water area; temperature has weaker impact. • Open water near bends may indicate ice jam-prone zones during freezing period.