Investigation of Various Factors of Extremely High Turbidity along the Coast of Matarbari, Bangladesh

Abstract

 The objective of this study is to identify the dominant factors that contribute to extreme turbidity along the coast around Matarbari Port, Bangladesh, and to investigate how the observed turbidity depends on the identified factors. Understanding the characteristics of this extreme turbidity is of importance for countermeasures against severe siltation around ports. Among the factors analyzed, the water level in the Meghna River and Karnaphuli River and the local significant wave height showed a moderate correlation with the measured daily average turbidity, while significant wave period, tidal amplitude, and surface current velocity had weak correlations with the measured turbidity in the Matarbari Port area. Satellite data from the Moderate-Resolution Imaging Spectroradiometer (MODIS) was used to capture the spatiotemporal variation in turbidity in Bengal Bay, including the Matarbari Port area. Through analysis, it was found that there is an approximately 30-day time lag between the river discharge from the Meghna River and the high turbidity around Matarbari. Based on this finding, linear regression was performed, and the obtained regression model showed good predictive ability for the observed daily average turbidity only as a function of local significant wave height and water level at the mouth of the Meghna River.