Development of Regional Algorithm to Estimate Suspended Sediment Concentration (SSC) Based on the Remotely Sensed Reflectance and Field Observations for the Hooghly Estuary and West Bengal Coastal Waters

Abstract

The present study presents regional algorithm to estimate suspended sediment concentration (SSC) from remote sensing reflectance (Rrs) and field observations for the Hooghly Estuary and coastal waters of West Bengal. The understanding of the suspended sediment concentration along the coastal waters is essential to estimate the environmental impact of erosion and depositional process. The water samples were collected onboard for cloud-free days along the Hooghly Estuary and along the open coast of West Bengal. The field synchronous OCM data are then processed for geometric corrections, and remote sensing reflectance at pixel level is retrieved. The SSC is observed to vary from 35 to 75 mg/l along coastal waters and 24 to 270 mg/l in Hooghly Estuary. The sum of Rrs at 555 and 620 nm is observed to have high correlation with the SSC observed by conventional method. An exponential relation is observed to show better comparison with an R2 value of around 0.74. From observations, it is evident that the reflectance values and SSC for Hooghly Estuary (particularly clay sediment) yielded good correlation than coastal waters for sand sediment concentration. As the regional algorithm developed for the West Bengal coastal area gives better results, this algorithm can used for further research and to estimate SSC in the study area.