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163Figure 14. Conjectural meander pathways in the Hooghly Estuary. Present situation isshown by the thick white line. A possible former pathway is indicated by the dotted line. Thelocation of a training wall that may have triggered avulsion is indicated (Pethick, 2008).West bank157. The western or Hugli bank of Sagar Island is almost wholly accretional at the presenttime. It appears from anecdotal evidence that this is a relatively recent development and thaterosion formerly characterized much of this coast. There may be several explanations of thisreversal from erosion to accretion. One possibility proposed here is again connected to thetidal meander, this time of the Hugli itself. The mangrove area located immediately south ofthe arrow shown in Figure 14 represents a former meander bend. The meander pathway thatmay have caused this erosion is shown as a dotted white line in Figure 14. Avulsion of thismeander to its present pathway, shown as a thick white line in Figure 14, may be a result ofthe construction of a training wall running north east from the extreme northerly tip ofNayachar Island. This training wall could have intercepted the dominant ebb tidal flow thatpreviously was directed into the Haldia channel, forcing flow eastward into the main channeland causing avulsion of the meander to its present location. This in turn has led to the westcoast of Sagar becoming located at the extreme southerly tip of the inside of the meanderbend and thus receiving sediment from the flow rather than losing it to erosion as formerlywas the case. Majority of sediment, both fine sand and silts are derived from the land and