Lakeshore transformation and water color dynamics: A satellite-based 23-year assessment of nine plateau lakes in Yunnan, China

Abstract

Study region Nine plateau lakes in Yunnan, China. Study focus We developed an extended lakeshore utilization classification framework to categorize lakeshores as natural, agricultural, or artificial using fixed maximum shorelines. We then derived the Forel–Ule Index (FUI) of the nine lakes from MODIS to characterize water color dynamics during 2000–2022. We quantified lakeshore composition and transformation trajectories, assessed FUI trends, and examined contemporaneous and one- and two-year lagged lakeshore–FUI associations. New hydrological insights for the region Lakeshore classification achieved 98.8% overall accuracy. Four lakes exhibit intensification, two show adjustment, and three remain relative stable. Artificial lakeshore increases from 29.1% to 45.2% in Erhai, while agricultural lakeshore increases from 36.3% to 73.5% in Chenghai. Significant upward FUI trends occur in Erhai, Chenghai, Yangzong, and Xingyun, whereas Lugu exhibits a downward trend and the other lakes show no significant trends. Contemporaneous lakeshore–FUI associations is significant for natural and artificial lakeshore in Erhai and Lugu and for agricultural lakeshore in Yilong, with none supported elsewhere. The lagged analysis shows that five lakeshore–FUI associations strengthen and five weaken. These contrasting responses indicate that lakeshore transformation alone does not determine water color dynamics, which is conditioned by lake-specific environmental and anthropogenic contexts. The proposed framework supports integrated lakeshore and water color monitoring and coordinated lake–watershed management in Yunnan and comparable lake systems.