Monitoring of Coastal Geo-Environment for Hazard Mitigation: A Case Study of Machilipatnam Region, Andhra Pradesh, India

The coastal zone is highly dynamic, which responds in various ways to human interventions and extreme weather events. Tropical storms cause enormous damage to the coastal region and its communities during landfall. Many of the world’s largest deltas are densely populated and are increasingly vulnerable to natural disasters. The Krishna district within the river delta, is amongst the few districts with very high proneness to cyclone hazards. Machilipatnam in Krishna district is one of the oldest coastal towns in Andhra Pradesh, situated on a series of ancient beach ridges. Two major storms struck this region in the last half-century causing large scale devastation. The extent of inundation from multiple flood events can be a very good indicator for flood hazard zonation. The lateral expansion of Machilipatnam town is analysed in GIS environment based on time series satellite data. The developmental activities in the near shore zone are modifying the pristine coastline configuration. This is evident from shoreline monitoring. It is observed that there is a net increase in the extent of mangroves, indicating a better protection to the town against tropical storms. The unplanned growth of aquaculture may be an amplifying factor for coastal flooding, particularly if it is interfering with the drainage system. In addition to the existing flood protection measures, the areas suitable for shelter belt plantation and mangrove regeneration are identified for coastal vulnerability reduction.