Nondimensional Methods to Classify the Tidal Inlets Along the Karnataka Coastline, West Coast of India

Abstract

This classification of tidal inlets is essential to maintain the stability of the inlets as well as to study the changing patterns of tidal inlets in India. Tidal inlets around the world have been classified as either wave-dominated or tide-dominated or river-dominated, since the 1970s. Tidal inlet classification for 471 inlets along the coast of India was carried out by Vikas M et al., based on wave and tide information. But only 30 inlets were considered for river-based classification due to lack of discharge information. In order to consider the river-based classification, the river flood discharge was estimated using Synthetic Unit Hydrograph (SUH) methods for Karnataka coast. In this study, 29 tidal inlets along the coast of Karnataka are selected for the classification based on river discharge. The classification has been done in two aspects; without considering wave period $\left( {{\text{i.e.}} \frac{{Q_{tide} }}{{\sqrt {{\text{gH}}^{5} } }}\,{\text{versus}}\, \frac{{Q_{f} }}{{\sqrt {{\text{gH}}^{5} } }} } \right)$ and by considering wave period $\left( {{\text{i.e.}} \frac{{{\text{Q}}_{tide} }}{{{\text{g}}^{1.75} {\text{H}}^{1.25} {\text{T}}^{2.5} }} \,{\text{versus}}\, \frac{{{\text{Q}}_{f} }}{{{\text{g}}^{1.75} {\text{H}}^{1.25} {\text{T}}^{2.5} }}} \right)$ where Q_tide is peak tidal discharge, Q_f is river discharge and H is wave height. The results obtained are validated with hydrological and geomorphological classifications and the dominant forces over the dynamics of the inlets are determined.