Survey, 2019-01-01, Russia

Gorky Reservoir, algal-bloom mapping

Synchronised high-resolution LIF LiDAR mapping during an algal-bloom period, 4,087 data points at 8-metre resolution, used to derive regional Sentinel-2 retrieval models for chlorophyll-a and total suspended matter. Reported in Remote Sensing, 2019.

Published figures

Interpolated fields from the campaign, reproduced as issued. Plate titles carry the LIFL-9 under its original designation, UFL-9.

Interpolated chlorophyll a field mapped along the lidar track, Gorky Reservoir, Volga, Gorky Reservoir, 2023 — Fig. 1Chlorophyll a

Interpolated CDOM absorption at 440 nm field mapped along the lidar track, Gorky Reservoir, Volga, Gorky Reservoir, 2023 — Fig. 2CDOM absorption, a440

Interpolated total suspended solids field mapped along the lidar track, Gorky Reservoir, Volga, Gorky Reservoir, 2023 — Fig. 3TSS

Gorky ReservoirVolga Basin

● Gorky Reservoir 2023, 2023-09-16 → 2023-09-1767,763 measurements IDW interpolation, 600 samples

Chl-a1.73172µg/L

TSS2.773.72mg/L

Fig. 4 Campaign scan. 67,763 lidar returns along the ship track, switchable across Chl-a, TSS. Field view interpolates the channel across the surveyed water from the same measurements (inverse-distance weighting). Shoreline: Natural Earth.

The Gorky Reservoir, on the Volga, develops intense blue-green algal blooms in summer, during which its optical properties vary on scales of tens of metres and shift with currents and wind, conditions under which station-based sampling is largely uninformative. To capture that variability, in-water constituents were measured by ultraviolet fluorescence LiDAR alongside remote-sensing reflectance from a single radiometer, run together from a high-speed gliding motorboat.

In about two hours the survey collected 4,087 synchronised LiDAR and radiometric measurements at 8-metre resolution. The portion coincident with a Sentinel-2 overpass was used to build regional retrieval algorithms for chlorophyll a and suspended matter, the first such work for inland waters of this kind, and transferable to the other Volga reservoirs. Published in Remote Sensing (2019).