Japan Geoscience Union Meeting 2019

Presentation information

[J] Oral

A (Atmospheric and Hydrospheric Sciences ) » A-OS Ocean Sciences & Ocean Environment

[A-OS15] Freshwater discharge through rivers and estuaries to the ocean

Mon. May 27, 2019 3:30 PM - 5:00 PM 102 (1F)

convener:Shinichiro Kida(Research Institute for Applied Mechanics, Kyushu University), Dai Yamazaki(Institute of Industrial Sciences, The University of Tokyo), Yosuke Alexandre Yamashiki(Earth & Planetary Water Resources Assessment Laboratory Graduate School of Advanced Integrated Studies in Human Survivability Kyoto University), Humio Mitsudera(Institute of Low Temperature Science, Hokkaido University), Chairperson:Shinichiro Kida(RIAM, Kyushu University), Humio Mitsudera(Hokkaido University, Institute of Low Temperature Science), Yosuke Yamashiki(GSAIS Kyoto University)

4:15 PM - 4:30 PM


*Shweta Yadav1, Yamashiki Yosuke1, Junichi Susaki1, Kanako Ishikawa2, Yoh Yamashita1 (1.Kyoto University, 2.LBERI)

Keywords:Chlorophyll-a, Lake and Coastal Water, Satellite-Remote Sensing

Chlorophyll-a is an optically active compound (OAC) commonly used as a proxy for phytoplankton biomass in an aquatic environment. Retrieving the concentration of chlorophyll-a remains a challenge due to the presence of several OAC particularly in water bodies which are in proximity to the land-based activities. In this study, an effort has been made to estimate the chlorophyll-a concentration of both the freshwater Lake Biwa and the coastal water of Wakasa Bay in Japan. A spectral decomposition algorithm was used to determine the chlorophyll-a using the satellite images. The algorithm was applied to the satellite images from two different sensors namely Landsat-8 /OLI and Sentinel-2A/MSI. The satellite-derived chlorophyll-a concentration for the lake and coastal water from two different sensors were compared to assess the performance of both the sensors. The accuracy of the chlorophyll-a results derived from the images was evaluated with the in-situ measurement data of the chlorophyll-a for the Lake Biwa and the coastal water of Wakasa Bay. Both satellite sensors appear to give the best results for the coastal water (R2 > 0.80) with an RMSE < 0.3 µg/L. However, slight underestimation of chlorophyll-a noted for the Landsat-8 image with an increase in chlorophyll-a concentration. For the lake water, Sentinel-2A results were relatively better (R2 > 0.70) than Landsat-8, with an RMSE of < 1.0 µg/L. The obtained results will be useful to evaluate the primary productivity of both freshwater and coastal water body.