Remote sensing algorithms for monitoring eutrophication in Ishizuchi storm water reservoir in Kochi Prefecture, Japan / Algorithmes de télédétection pour la surveillance de l'eutrophisation du réservoir d'orage d'Ishizuchi dans la Préfecture de Kochi, Japon

• Published in: Hydrological sciences journal Vol. 50; no. 3
• Main Authors: Ibrahim, Abdoul Nasser, Mabuchi, Yasushi, Murakami, Masahiro
• Format: Journal Article
• Language: English
• Published: IAHS Press 01.06.2005
• Subjects: absorption spectrale; band ratio; chlorophyll; chlorophylle; modèle de régression; rapport de bande; regression model; spectral absorption; turbidity; turbidité
• ISSN: 0262-6667; 2150-3435
• DOI: 10.1623/hysj.50.3.525.65024

Remote sensing technology is being conceived as a cost-effective tool to monitor the eutrophication problem in shallow inland lakes and reservoirs. The objective of this study is to develop hyperspectral remote sensing algorithms for chlorophyll and accessory pigments retrieval in the Ishizuchi Reservoir in Japan. The laboratory reflectance data of 207 field samples with manipulated pigment and suspended sediment concentrations were measured between 400 and 700 nm with a hyperspectral spectroradiometer, and integrated into 60 contiguous narrow bands. Band ratio and spectral absorption algorithms were developed by regression analysis with the observed chlorophyll measurements, and their estimation accuracies were evaluated using the RMSE of the estimates. Algorithms developed from spectral absorption ratios a(675 nm)/a*(675 nm) for five different classes of total pigment concentrations were more accurate than the algorithms based on band ratios R rs (538 nm)/R rs (488 nm), R rs (581 nm)/R rs (463 nm) and R rs (674 nm)/R rs (622 nm) as a result of removing the influence of overlapping absorption and scattering by water molecules and suspended solids from total absorption spectra.