Author(s): Senthilkumar R; Murali K; Sundar V
Keywords: Inlets; Littoral drift; Waves; Tides; Longshore velocity
Abstract: Tidal inlets are commonly used as navigation channel for fishing and other small vessels. It is vital to keep the mouth of such inlets open and free from sand bar formations. Further, the tidal ingress enhances flushing, thus enhancing the water quality. During fair weather season, the availability of water depth in the inlet decreases due to lowered wave and current activity. The formation of sand bars due to the dominance of the alongshore sediment transport in the vicinity of the mouth of the inlet as well as the sediment brought in by the inlets are responsible for degradation of the smooth flushing of tidal inlets. The dynamics of tidal inlets is rarely a subject of systematic study due to the complexities involved. In the present investigation, an attempt has been made to numerically model a dynamic inlet situated at Kondurpalem, (14.02660 N, 80.1534180 E) Andhra Pradesh, along the east coast of India. Since east coast of India experiences a net littoral drift of about one million m3 per annum, which is one of the largest in magnitude, this needs to be considered in the analysis in the modeling of the sand formation and the associated phenomena. A frequency domain wave model has been used to compute the wave induced radiation stresses. The wave induced currents have been obtained by solving the depth averaged circulation model using the radiation stresses. The sediment transport and morphodynamics were derived from the currents induced by waves and tides. The model results show the extent of siltation and the regions of inlet that needs improvement. Thus, the model results help in the design of training works and further to validate the effectiveness of the training works.