Monthly statistical coefficients for discharge and Brefeldin A calibration and validation.VariablePeriodR2ENSPBIASRSRDischargeCalibration0.790.7521.40.50Validation0.800.6421.70.60TSSCalibration0.390.34− 9.40.8Validation0.320.21− 2.20.8Full-size tableTable optionsView in workspaceDownload as CSV
Fig. 6. Monthly calibration and validation output for (a) monthly flow and (b) TSS; sediment data derived from MODIS images is used (measured in solid line, modeled in dashed line and points are daily TSS estimates).Figure optionsDownload full-size imageDownload as PowerPoint slide
Fig. 7. Comparison of measured and simulated (a) flow and (b) TSS.Figure optionsDownload full-size imageDownload as PowerPoint slide
The model fitness to purpose was the major criteria applied in assessing the usability of MODIS images generated TSS time series data. Despite a modest NSE for both calibration and validation (0.39 for calibration and 0.32 for validation) periods the model could bracket not more than 33% of the MODIS generated TSS data in the calibration period and 22% of it in the validation period. Two major assumptions may have played a critical role in creating the “black holes”. The first assumption is that the regression equations used to generate the time series are stable over the last ten years. While the land cover and the economic activity in the watershed seems unchanged over the last ten years the factors affecting the optical characteristics of the water are far complicated than this.