Shoreline evolution due to construction of rubble mound jetties at Munambam inlet in Ernakulam–Trichur district of the state of Kerala in the Indian peninsula

Munambam inlet is in the West Coast of India falling in Ernakulam–Trichur districts of Kerala. This is the point where the north branch of Periyar river after joining Chalakudi and Pullut rivers meets the Arabian Sea. Due to the littoral drift from the north direction, a sand spit had formed at the mouth which caused frequent capsizing of boats. In order to arrive at a permanent problem, two breakwaters of length 360 m and 625 m had been constructed in the year 2000. After the construction of the breakwaters, the sand spit disappeared and there was considerable improvement in the bathymetry at the initial periods but the problem recurred. This paper highlights the details of the shoreline evolution from 1975 to 2012 derived from the actual field data and MIKE 21. The results indicate that the advancement of shoreline on either sides of the inlet is a peculiar phenomenon unlike erosion on one side and accretion on the other. Short term solutions for the management of the recurring problems are suggested in this paper. Long term solutions to the problem are also suggested, such as calling for the attention of the state and local government and research organizations.