Water level dynamics monitoring for the lakes on the Yunnan plateau by using surface water and ocean topography (SWOT) satellite data

Study region This study focuses on the Yunnan Plateau in southwestern China, examining nine major plateau lakes: Dianchi, Erhai, Fuxian Hu, Chenghai, Lugu Hu, Qilu Hu, Xingyun Hu, Yangzonghai, and Yilong Hu, all located in high-altitude settings with complex surrounding terrain. Study focus Using newly released Surface Water and Ocean Topography (SWOT) satellite data to monitor lake water-level dynamics, we propose an automated method to retrieve high-precision time-series water levels from SWOT observations. The method aims to improve spatiotemporal monitoring capability and provide a complementary alternative to the official SWOT LakeSP product. New hydrological insights for the region The results show that SWOT, combined with the proposed method, can monitor the nine lakes at a monthly scale with high accuracy (achieving an RMSE of less than 0.09 m). The retrieved water levels reveal clear seasonal variations, with minimum levels generally occurring in April–May and maxima from August to November, consistent with regional precipitation patterns. Intra-annual water-level fluctuations range from 0.23 to 1.20 m. Most lakes exhibit periodic annual variations, whereas Fuxian Hu and Yangzonghai show sustained water-level declines over the available observation period.