Channel-morphology-based characterisation and assessment of spatial ice-jam predisposition along the Inner Mongolia reach of the Yellow River

Abstract. Ice-jam flood prevention and mitigation remain practical challenges in cold-region river management, making efficient identification of ice-jam-prone reaches essential. Morphology-based assessment can support preliminary screening in data-scarce regions. This study developed a method for assessing spatial ice-jam predisposition along an approximately 800 km reach of the Yellow River in Inner Mongolia. Building on a conventional model, we introduced indicators of shoal development and channel planform complexity, constructed four configurations of the ice-jam predisposition index using different indicator combinations, compared the results at three assessment scales, and examined their spatial correspondence with historical ice-jam records. Predisposition varied markedly, with High-class units concentrated in sections characterised by complex bar-channel configurations and pronounced morphological changes. At the 500 m scale, the full four-indicator configuration classified 11.85 % of the units as High; 78.7 % of historical records occurred in Medium- or High-class units, and the High-class enrichment ratio reached 2.87. Incorporating shoal development and channel planform complexity improved the differentiation of morphologically complex reaches. The proposed method supports preliminary screening of ice-jam-prone reaches and ice-jam flood management in data-scarce cold-region rivers.