干旱区生态环境知识资源中心

A brief review of various physical processes acting in the Gulf of Kachchh (GoK), which have prominent roles in Gulf dynamics, is presented in this article. The eddies present in the GoK confirm that they are permanent features of the GoK circulation. Accurate estimation of residual currents and eddies in an active industrial coastal zone like the Gulf of Kachchh is important because of its potential applications with respect to discharge of pollutants. Though GoK is considered as a well-mixed system, recent studies revealed that only the central Gulf is well mixed. Stratification in temperature and salinity is noticed in the eastern Gulf, where a cold and high saline tongue is observed in the subsurface layers. Model results indicated the effect of seasonally changing winds the circulation. During southwest monsoon, the predominant westerly winds enhance the flood currents by about 20% and reduce the ebb currents significantly. In spite of semi-arid climate and lack of major rivers flowing into it, the Gulf is highly turbid with suspended sediment concentrations (SSC) during October-November 2002 ranging between 0.5 mg l(-1) and 674 mg l(-1).