Temperature and land use influence on spatiotemporal dynamics of particulate composition in Chinese Eastern Plain Lakes: a remote sensing-based study

Abstract

The composition of particulate matter in lakes is considered a key indicator of underwater light-field dynamics and the proportion of organic matter. In this study, reflectance from Sentinel-3 OLCI (Ocean and Land Colour Instrument) imagery at 510, 560, and 620 nm was utilized to estimate the organic suspended matter to total suspended matter ratio (OSM/TSM) in lakes, serving as an indicator of particulate composition. The multi-year spatiotemporal characteristics of OSM/TSM in 76 lakes (>10 km 2 ) from 2016 to 2023 were investigated. Generalized linear models were used to explore the relative ranking of meteorological and anthropogenic correlates, while a pooled linear mixed-effects model was used for association analysis. The results revealed that OSM/TSM mainly ranged from 0.2 to 0.6, and 79.96% of the lakes showed an increasing trend in OSM/TSM according to the Mann-Kendall test. Additionally, peak OSM/TSM values were often observed in summer and autumn, while the lowest values occurred in spring and winter. Temperature had the highest normalized relative weight (44.93%) for intra-annual OSM/TSM variation. For inter-annual variation, land-use variables had a combined normalized relative weight of 58.00%. The OSM/TSM estimates provided by this study for large inland lakes can serve as a valuable reference for future lake monitoring and assessment in the Eastern Plain Lakes of China.