Visakhapatnam: Parts of Vizag’s coastline are eroding at an average of 1.40 metres per year over the last 25 years. Of the total 135km of the coast, about 38.4 km is eroding at an average of -1.40 m/year. About 74.6 km of coastline appears to be accreting with an average of +1.08 m/year while around 41.4 km coast is found to be stable.
The condition of Vizag shoreline was assessed by the Andhra Pradesh Space Applications Centre, using satellite images. Pictures of Vizag shorelines were extracted from multi-temporal satellite images for 1989, 1999, 2005, 2010, 2012 and 2015 using digital image processing and visual interpretation.
The study was carried out using multi-resolution and multi-temporal satellite data from Landsat TM and IRS. The datasets were gathered on cloud-free days on different dates over a chosen period from 1989 to 2015.
“Beaches were analysed to assess their evolution, like erosion and accretion associated with human intervention and climatic condition. Both natural and anthropogenic proce-sses along the coast control the erosion as well as the accretion activities of the coastal zones.
In this study, high-resolution im-ages taken from 1989 to 2015 at an interval of about 5/10 years and topographic maps were collected to determine coastline changes. The present shoreline maps show the shoreline erosion accretion pattern in the coastal area of Visakhapatnam district by using different sources of remote sensing data,” said scientist at Andhra Pradesh Space Applications Centre Kannan R., who collected the satellite data and analysed cha-nges of Vizag shoreline.
The study paper “Detection of Shoreline Changes Visakhapatnam Coast, Andhra Pradesh from Multi-Temporal Satellite Images” was also published in the Journal of Remote Sensing & GIS.
The study found that in a natural environment, erosion and accretion at a certain area are normally in balance. If erosion occurs in a particular area, accretion would also be found. Interestingly, in this study this is not evident along Vizag shore, proving that the sediment transport in the area has been disturbed.
