Spatiotemporal decoupling of littoral and lacustrine geosmin dynamics: Implications for early warning in drinking water reservoirs

Littoral bloom foreshadows,
a five-week warning, then taste
downstream borne.
Geosmin
Taste and odor
Early warning
Planktothrix agardhii_
Spatiotemporal decoupling

WR2026: Yuying Gui#, Tengxin Cao#, Ming Su*, et. al. Spatiotemporal decoupling of littoral and lacustrine geosmin dynamics: Implications for early warning in drinking water reservoirs. Water Research 2026;XXX:XXXXXX 10.1016/j.watres.2026.125788.

Authors
Affiliations

Yuying Gui

Tengxin Cao

Jie Yang

Tianjin Hydraulic Research Institute

Jihui Qin

Tianjin Yuqiao Reservoir Authority

Ziyi Yang

Qi Zhang

Institute of Hydrobiology, Chinese Academy of Sciences

Yufan Ai

Jiao Fang

Yingjie Li

Yuanhong Xiao

Tianjin Yuqiao Reservoir Authority

Zhixiang Hao

Tianjin Hydraulic Research Institute

Zhengyan Li

College of Environmental Science and Engineering, Ocean University of China

Min Yang

Published

Mar 20, 2026

Doi

Abstract

The relationship between cyanobacterial niche characteristics and the transport dynamics of harmful metabolites to drinking water intakes remains poorly understood. This study integrated a national survey with a five-year high-frequency monitoring program to characterize these dynamics, focusing on the potent odorant geosmin. The national investigation revealed that 14% of surveyed sites exceeded the odor threshold of 10 ng L-1, indicating a non-negligible risk. In the YQ Reservoir, Planktothrix agardhii was identified as a primary producer. Monitoring revealed a distinct spatiotemporal decoupling: shallow littoral zones functioned as production centers where P. agardhii biomass peaked 8 days prior to the lacustrine intake. Time-lagged correlation analysis indicated that littoral biomass predicts intake geosmin concentrations with a 5-week lead time (R2 = 0.41). Ammonium was identified as the key regulatory factor, exhibiting its strongest correlation with geosmin in littoral zones (R2 = 0.37), though this linkage attenuated during transport. This proposed mechanistic transport model and tiered framework shift surveillance from reactive intake sampling to proactive littoral sentinel stations, establishing a critical predictive window for preventive intervention in reservoir-dependent water supplies.

Graphical abstract

Citation

Add to Zotero

@article{gui2026spatiotemporal,
  title = {Spatiotemporal decoupling of littoral and lacustrine geosmin dynamics: Implications for early warning in drinking water reservoirs},
  journal = {Water Research},
  pages = {XXX},
  volume = {499},
  year = {2026},
  issn = {0043-1354},
  doi = {10.1016/j.watres.2026.125788},
  url = {https://www.sciencedirect.com/science/XXXX},
  author = {Yuying Gui^#^ and Tengxin Cao^#^ and Jie Yang and Jihui Qin and **Ming Su**^\*^ and Ziyi Yang and Qi Zhang and Yufan Ai and Jiao Fang and Yijing Li and Yuanhong Xiao and Zhixiang Hao and Zhengyan Li and Min Yang},
  keywords = {2-methylisoborneol (MIB), Cell lysis-mediated release, Drinking water early warning, Growth-phase dependent release, Taste and odor}
}