Evaluation of stream water quality data generated from MODIS images in modeling total suspended solid emission to a freshwater lake

• Published in: The Science of the total environment 2015-08, Vol.523, p.170-177
• Main Authors: Ayana, Essayas K., Worqlul, Abeyou W., Steenhuis, Tammo S.
• Format: Article
• Language: English
• Subjects: Basins; Calibration; Emission analysis; Environmental Monitoring - methods; Freshwater; Freshwater monitoring; Freshwaters; Geologic Sediments - analysis; Hydrology; Lake Tana; Lakes; Lakes - chemistry; MODIS; Mouth; Rivers; Rivers - chemistry; Satellite Imagery; Sediments; TSS; Water Movements; Water Pollutants - analysis
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2015.03.132

Modeling of suspended sediment emission into freshwater lakes is challenging due to data gaps in developing countries. Existing models simulate sediment concentration at a gauging station upstream and none of these studies had modeled total suspended solids (TSS) emissions by inflowing rivers to freshwater lakes as there are no TSS measurements at the river mouth in the upper Blue Nile basin. In this study a 10year TSS time series data generated from remotely sensed MODIS/Terra images using established empirical relationship is applied to calibrate and validate a hydrology model for Lake Tana in Upper Blue Nile Basin. The result showed that at a monthly time scale TSS at the river mouth can be replicated with Nash–Sutcliffe efficiency (NS) of 0.34 for calibration and 0.21 for validation periods. Percent bias (PBIAS) and ratio of the root-mean-square error to the standard deviation of measured data (RSR) are all within range. Given the inaccessibility and costliness to measure TSS at river mouths to a lake the results found here are considered useful for suspended sediment budget studies in water bodies of the basin. •MODIS images used to generated total suspended sediment (TSS) time series data for a stream•The usability of the data to model TSS emission into a lake is evaluated•Generated data were capable of modestly reproducing monthly variations•The PBIAS indicated slight underestimation of suspended sediment