Impacts of floating photovoltaic stations on the spatial distribution of chlorophyll-a in lakes

Abstract

To assess the impact of FPV stations on chla concentrations in lake water bodies on a global scale, we selected 150 FPV installations across three climatic zones worldwide. Using a total of 5,458 scenes of Landsat imagery from 2000 to 2022, we simulated chla concentrations before and after the installation of FPVs. Hotspot analysis was then applied to compare the effects of FPV installations on the spatial clustering of chla concentrations in lake water. The results revealed that: (1) In tropical and temperate zones, the concentration of chla in the lake water where FPVs are located has decreased; in cold zones, the decline rate of chla concentration in the lake water of FPVs has slowed down.(2) FPVs alter the spatial clustering of chla. In tropical zones, low-value clustering increases while high-value clustering decreases. In cold zones, both high-value and low-value clustering increase. In temperate zones, both high-value and low-value clustering decrease. (3) The coverage of FPVs is not the determinant factor influencing chla concentrations. In fact, larger lake surface areas generally corresponded to lower chla concentrations.(4) Compared with the significant influence of TSI on chla concentration, the impact of FPVs on chla concentration is relatively weak. Although path analysis reveals that the TSI has a significant and strong positive causal effect on chla, our results based on remote sensing imagery and spatial clustering analysis primarily reflect correlations rather than strict causality.