Monitoring river ice is important for hydrological research and water resources management. Given the severe shortage of field observations, remote sensing can provide an effective complementary method. However, previous river-ice remote sensing studies have primarily assessed satellite monitoring capabilities or economic applications, with little attention to high-elevation areas such as the Tibetan Plateau. Remote sensing research on Tibetan Plateau river ice remains limited, as does our understanding of river ice at the catchment scale.

The Cold-Region Remote Sensing Hydrology group at the Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, selected the Babao River basin, a representative alpine catchment in the northeastern Tibetan Plateau, to investigate the spatial and temporal distribution of high-elevation river ice at the basin scale. Using 447 Landsat images acquired during river-ice seasons from 1999 to 2018 and the conventional normalized difference snow index (NDSI), we monitored river ice over a long time series. The mean validation kappa coefficient was 0.973. Mean river-ice area during the ice season showed a slight declining trend and was negatively correlated with air temperature (Figure 1). Gentle slopes and high elevations favored river-ice formation (Figure 2), while spring ice melt supplemented river discharge. This work was the first to reveal basin-scale distribution patterns and trends in river ice on the Tibetan Plateau, providing a reference for further research in the region.

The findings were published in Remote Sensing of Environment. See:

Haojie Li, Hongyi Li, Jian Wang, Xiaohua Hao. (2020). Monitoring high-altitude river ice distribution at the basin scale in the northeastern Tibetan Plateau from a Landsat time-series spanning 1999-2018. Remote Sensing of Environment. 247: 111915. https://doi.org/10.1016/j.rse.2020.111915