Abstract

MONCAYO ERASO, Ricardo Javier  and  TRINDADE GALO, María de Lourdes Bueno. SPATIO-TEMPORAL ASSESSMENT OF TROPHIC STATE OF A LARGE LAKE USING MOD09GA IMAGES. Cienc. Ing. Neogranad. [online]. 2017, vol.27, n.1, pp.27-42. ISSN 0124-8170.  https://doi.org/10.18359/rcin.1893.

Although the empirical relationship between satellite imagery and data collected in the field Secchi disk has been demonstrated by previous studies in inland water bodies, creating the basis line for spatiotemporal monitoring to identify seasonality index trophic state calculated with Secchi disk (TSISD) has been little explored in monitoring large lakes. To make a practical example of the spatioseasonal food web in the Porto Primavera reservoir (State of São Paulo Brazil) from May 2000 to April 2015, images generated by the MODISTerra sensor is used, and, also two field works were performed to obtain values Secchi Disk (SD). These values were used to adjust and validate a model of correlation between reflectance values centered on 645nm and DS band. The results indicated that the model has a high coefficient of determination (R2 = 0.80) and moderate error associated with the estimates (RMSE = 0,47m). The analysis of seasonal variation (IETDS) shows the following pattern: the transparency of the lake is affected by the dry and rainy seasons. The average value of the sampling stations located on the lake classify it as oligotrophic, next to the mouth of the Rio Pardo region, it has an eutrophic classification for a large part of the year; in the summer and fall seasons this condition extends to almost the entire northern region of the lake.

Keywords : reservoir; spatio-seasonal; surface reflectance; remote sensing; transparency.

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