The land - water boundary line, which is the shoreline, is continually changing due to various dynamic features like, bathymetric changes, wave conditions, currents, and orientation of coast. Therefore, the shoreline position oscillates incessantly with regard to time. Shoreline oscillation amounts to erosion/accretion problem. In addition, the frequent storms and the sea level rise will lead to coastal flooding and which in turn causes accretion/erosion phenomena along the coast. In this paper, the shoreline changes are studied by utilizing numerical approach, due to the construction of a fishery harbour on Kerala coast in India. SW and LITPACK modules of Mike 21 software are adopted for the prediction of shoreline evolution. The analyses reveal that there are tremendous accretion on the northern side and considerable erosion on the southern side after the construction of the harbour
The land – water boundary line can be taken as the shoreline (Dolan et al.1980). But the shoreline position will change constantly with respect to time, depending on the dynamic features of water level. So, considering the purpose and use of data, the period of time is adopted and the shorelines are measured in a temporal frame. The land – water boundary line at a particular time is only the instantaneous shoreline at that particular time.
The major factors influencing the evolution of shorelines are movement of sediments, rises in sea level and coastal interference. The hydrodynamic features like nearshore conditions, river aspects, storm surges and the categories of coastal landforms also affect the shoreline (Narayana and Priju, 2006; Scott, 2005; Kumar and Jayappa, 2009). The shoreline evolution is directly connected to accretion or erosion problem on the coast. The likely shoreline oscillations and the actual connected risk evaluation for various time periods are the main necessity (Burgess et al. 2001). Depending upon the sediment supply, shoreline may have three different conditions in the system of sediment budgeting. These conditions can be called as deficit, balanced and surplus condition. The considerable deviations in sediment supply, with short or long-time span, causes deficit/surplus sediment budget leading to shoreline changes (Mukhopadhaya et al. 2012). Generally, sea level rise following storms, global warming etc. will cause coastal flooding and erosion or accretion occur along the coastline (Dattatri et al. 1997).