Application of IRS-P4 OCM data to study the impact of tidal propagation on sediment dynamics in the Gulf of Kachchh

Abstract

This paper reports observations with respect to suspended sediment dispersal pattern at various stages of the tide cycles using the Indian Remote Sensing Satellite (IRS-P4) Ocean Colour Monitor (OCM) data, exploiting the high temporal resolution of two days and specific narrow spectral channels suitable to retrieve suspended sediment concentration. The shelf region of the Gulf, west of its mouth, plays a key role in sediment dispersal pattern within the Gulf of Kachchh as is evidenced by different linear shaped, clockwise and anticlockwise circulation patterns. The suspended sediments are transported as a V-shaped front into the Gulf during flooding conditions and as linear plumes fanning out of the Gulf during ebb conditions. Sediments are being transported into the Gulf along the northern shore from the Indus delta during flooding phase, whereas the southern shore gets sediments from the southern parts of the mouth. The study of sediment dispersal pattern led to dividing the Gulf of Kachchh into six zones, having characteristic sediment dispersal patterns. The information is useful for maintaining the approach channels of ports in addition to understanding dispersal of pollutants such as oil slicks under tidal influence.