Shoreline Dynamics in Subarnarekha Delta Plain

Abstract

Shoreline morphodynamics refers to the counting the interaction, interface and adjustment of the seafloor topography and fluid hydrodynamic processes, seafloor morphologies and sequences of change dynamics involving the motion of sediment transports. Hydrodynamic processes include those of waves, tides and wind-induced currents. The present study involves an endeavour to appraise the transect wise investigative model for predicting the future shoreline position in order to monitor the shoreline shift along the coast in Balasore district of Orissa, India. The present study regarding the shoreline shift has been analysed in two ways such as short term and long term shoreline position analysis through Linear Regression (LR) model and End Point Rate (EPR) model respectively on the basis of these model generated shoreline dynamics nature, the future shoreline position has also been predicted. The model error or positional shift at each sample points (Transects) is observed. The positional error varies from −4.82 to 212.41 m. It has been found that model prediction error is higher in the mouth of river Subarnarekha. The overall error for the entire predicted shoreline was found to be 41.88 m by Root Mean Square Error (RMSE). In addition, further it was tested by means difference between actual and predicted shoreline positions using ‘t’ test and it has been found that predicted shore line is not significantly different from actual shoreline position at (t₁₃₂ = 0.278, p < 0.005). The obtained results of the present study suggest that the utilization of remote sensing data in addition with the GIS technology and statistical technique are very appropriate for extraction of shoreline and its shifting calculation. The magnitude of erosion is higher in the northern part of the coastline in the left bank area of Subarnarekha river estuary and also in the estuarine part of river Dugdugi and Burahbalang which is seen from the imagery of 1972 to 2010 and the model predicted shoreline also depicts the same. The southern part of the shoreline near Rasalpur, Joydevkasba is considerably stable indicated by the same model. The cross validation (The estimated shoreline was compared with the actual shoreline delineated from satellite imagery of 2013) shows that the model can predict consistent guesstimate of the shoreline position with satisfactory accuracy.