River mouth dynamics of Swarnamukhi estuary, Nellore coast, southeast coast of India

Swarnamukhi is an east flowing river having a total length of 130 km. This is an independent river which rises at an elevation of 300 m in the eastern Ghats ranges near Pakala village in Chittoor district of Andhra Pradesh, India. This study was carried out using multitemporal satellite images of IRS P6 LISS-III and Landsat 8 OLI/TIRS data from 2011 to 2015. The subsequent short term river mouth dynamics, coastal erosion and accretion rates have been calculated for the years between 2011 and 2015. Low river inflow, wind, tides, movement of the waves and littoral currents play a key role in the dynamic activities of erosion and accretion. The erosion rate from 2011 to 2015 was slightly decreased from 0.081 to 0.027 km2. The total net rate of accretion was estimated at 0.438 km2. The study shows during last five years (2011-2015) accretion is more than the erosion. High fluctuation of erosion and accretion are characteristics for the short term scale at river mouth.