Japan Geoscience Union Meeting 2025

Presentation information

[E] Poster

A (Atmospheric and Hydrospheric Sciences ) » A-HW Hydrology & Water Environment

[A-HW27] Biodiversity, nutrients and other materials in ecosystems from headwaters to coasts

Thu. May 29, 2025 5:15 PM - 7:15 PM Poster Hall (Exhibition Hall 7&8, Makuhari Messe)

convener:Noboru Okuda(Kobe University), Takuya Ishida(Hiroshima University), Masahiro Kobayashi(Kansai Research Center, Forestry and Forest Products Research Institute), Adina Paytan(University of California Santa Cruz)


5:15 PM - 7:15 PM

[AHW27-P17] Evaluation of Seasonal variation in carbon sequestration by seagrass in tidal flats, using UAV

*DINGCHANG CHEN1, Kento Kawanabe1, Mitsuyo Saito1, Takuya Akinaga2, Shin-ichi Onodera1 (1.Hiroshima University , 2.Okayama University)


Seagrass meadows have an important role as a blue carbon sink which mitigates climate change. However, they are currently facing risks of a reduction in coverage area and a decline in biodiversity due to human impacts and climate change. Unmanned aerial vehicles (UAVs) are so effective in flexibly monitoring variations in seagrass coverage with cost-effective and high-resolution images as compared with satellite images.
The research aimed to evaluate a seasonal variation in seagrass distribution in a tidal flat. The study area is located on the islands of the Seto Inland Sea in western Japan. In order to obtain seasonal variation in seagrass carbon storage, we collected monthly seagrass images in 2024, using UAV. Then we used the SVM method to classify the samples and calculated the seagrass coverage for subsequent estimates.
Seagrass cover showed clear seasonal variation, with the highest density in autumn at 31.8%. The peak in autumn cover could be attributed to a variety of environmental factors. For example, water quality is generally more stable in autumn, with moderate temperatures and increased nutrient availability, which is conducive to seagrass growth.
In contrast, summer had the lowest cover at 18.6%. This decline could be related to warmer water temperatures, increased turbidity, or potential stress factors, which are more prevalent in warmer months. Spring and winter cover was intermediate at 21.9% and 27.1%, respectively.