R S Mahendra

• Ph.D.
• Scientist at Indian National Centre for Ocean Information Services

The December 2004 Sumatra–Andaman earthquake emphasized consistent and comprehensive assessment of areas that are prone to the hazard of Tsunami. It also focused attention on the hazards that could be posed by large subduction zone earthquakes and the Tsunamis that could be further generated. Due to the extremely high vulnerability in the Andaman I...

A very severe cyclonic storm Phailin, a category-5 hurricane, was developed over the north of Andaman and Nicobar Islands on 9 October 2013. Subsequently, it propagated towards north– northwest and made landfall at the Gopalpur coast, Odisha on 12 October1 . The present study area, Rushikulya estuary is in close proximity (15 km north) to the landf...

Coral reefs are one of the prominent marine ecosystems in the world. Coral reefs are facing threats from both natural and anthropogenic factors. Monitoring, protecting and studying these ecosystems are considered as a complex process because they are underwater features. Remote sensing can be quite useful in this by providing huge amount of databas...

Sea Surface Temperature (SST) derived from the NOAA AVHRR satellite data were used to generate the Degree of Heating Weeks (DHW) and Hot Spot (HS) products. Combination of the cumulative temperature anomalies and the thermal stress studies were yielded to synoptically identify the probable areas of bleaching. The bleaching status of the Andaman reg...

Effective prediction of coastal flooding and associated inundation caused by extreme weather events, such as cyclones and high waves or swells, is critical for coastal hazard mitigation and emergency response planning. A fully coupled ADCSWAN model (ADvanced Circulation+ Simulating WAves Nearshore), which uses unstructured grids, is utilized to sim...

Climate change is a global phenomenon that has enhanced sea-level rise and aggravated the prevailing coastal hazards that make coasts more vulnerable. The socioeconomic vulnerability of villages for the entire Andhra Pradesh state and buildings at the selected locations along the Andhra Pradesh coast is estimated to understand the level of risk due...

In this study, long-term hourly sea-level records from 18 tide gauge stations during 1972–2007 were analyzed to study the characteristics of astronomical tides, sea-level trends, and extremes around India's mainland. The de-tided signals were used to estimate these parameters and study tide and surge interaction. The observed sea level depicts sign...

India's coastline stretches about 7516 km and about 15% of the Indian population lives around the coast. Coastal population, ecosystem and infrastructure in the coastal zone are becoming increasingly vulnerable to natural disasters such as tsunamis and storm surges. These events not only destroy the life and ecosystem along the coast, but they also...

India has a vast coastline of ~7,500 km encompassing the west coast (eastern Arabian Sea), east coast (western Bay of Bengal), and islands. The coastal water of India is rich in a wide variety of marine biotic and abiotic resources that support the livelihood of millions through fishery, recreational activities, tourism, marine commerce, maritime l...

The coastal flood during the tropical cyclone Tauktae, 2021, at Chellanam coast, Kerala, India, has invited wide attention as the wave overtopping severely affected coastal properties and livelihood. We used a combination of WAVEWATCHIII and XBeach to study the coastal inundation during high waves. The effect of low-frequency waves and the rise in...

The study aims to estimate the extent of inundation and depth due to a storm surge event by selecting a worst-case cyclone track scenario for Andhra Pradesh, Odisha and West Bengal on the basis of historic data. Storm surge model results for the Orissa cyclone suggest that over 2,150 km2 of land is inundated with an extent of 45 km from the shoreli...

The coastal flood during the Tauktae cyclone, 2021, at Chellanam coast, Kerala, India, has invited wide attention as the wave overtopping severely affected coastal properties and livelihood. We used a combination of WAVEWATCHIII and XBeach to study the coastal inundation during high waves. The effect of low-frequency waves and rise in the coastal w...

Variations of chlorophyll-a (chl-a), sea surface temperature (SST) and net primary productivity (NPP) along with fish catch were studied along the coastal waters off Karnataka, west coast of India from January 2007 to December 2016. These variations are linked with the Indian Ocean Dipole and El Niño/Southern Oscillation—Niño3.4 SST index. NPP was...

The present study assesses patio-temporal variability of the greenness index of Indian mangroves of the Sundarban forest with bio-carbon flux during 1990-2020. The analysis of NDVI derived using Landsat data reveals the mangrove stress level was very high during the years 1990, 2006, 2007, 2009 and 2011, with 2011 km² mangroves were severely affect...

The coastal communities are the most vulnerable to climate vagaries, which affect their habitat and livelihood alike. Vulnerability assessments undertaken using quantitative or qualitative methods at macro- or micro-level need to capture the location and context so as to be able to use them towards improving mitigation and resilience strategies at...

The coastal vulnerability to multi-hazard study aims to assess the coastal zones of Andhra Pradesh that really are vulnerable to various oceanogenic hazards. Using high-resolution coastal elevation, the maximum extent of coastal inundation during extreme high waves of cyclones & tsunamis, shoreline change, and sea-level rise can be computed. Vulner...

Coral reefs are fragile and endangered ecosystems in the tropical marine and coastal environment. Thermal stress due to marine heat waves (MHW) could cause significantly negative impacts onthe health conditions, i.e., bleaching of the coral ecosystem. The current study is an attempt to quantify theintensity of coral bleaching in the Andaman regioni...

The estuaries are highly dynamic in terms of carbon cycling, considering the emission of CO2 to the atmosphere, which is quantitatively significant for the global carbon cycle. The estuaries along the east coast of India, which flow into the northwestern coastal Bay of Bengal, are located in the tropics extending between latitudes 9°N and 22°N. The...

The coastal zones of northern Odisha coast, western Bay of Bengal, are highly exposed to natural forcing. These regions are vulnerable due to natural hazards such as cyclones, tsunamis, floods, shoreline/beach erosion and sea-level rise. Further, the increased intensity and density of the extreme events in the recent decades have contributed more t...

The present study is to estimate the inundation extent and depth to estimate the extent of damage using geospatial technique caused due to a storm surge. This is achieved by selecting a worst-case cyclone track (Super Cyclonic Storm) scenario for three Indian states, Andhra Pradesh, Odisha and West Bengal based on the historic data. Over 1300 cyclo...

Nowadays due to the change in climatic conditions and proliferation in sea level, the coastlines are under high threat. The Gujarat coastline is studied in the current work. It is the longest coastline in India and is highly vulnerable to cyclones, earthquakes, floods, landslides, etc. These facts show the relevance of the present research. The par...

During November–December 2015, very heavy rainfall caused severe flood in Southern Tamil Nadu that resulted in severe damages with huge economic losses as per news agency Times of India. Remote sensing data from Sentinel-1 synthetic aperture radar (SAR) and Landsat-8. Operational land imager (OLI) images together with ancillary information such as...

The impacts of climate change are of particular concern to the coastal region of tropical countries like India, which are exposed to cyclones, floods, tsunami, seawater intrusion, etc. Climate-change adaptation presupposes comprehensive assessment of vulnerability status. Studies so far relied either on remote sensing-based spatial mapping of physi...

The impacts of climate change are of particular concern to the coastal region of tropical countries like India, which are exposed to cyclones, floods, tsunami, seawater intrusion, etc. Climate-change adaptation presupposes comprehensive assessment of vulnerability status. Studies so far relied either on remote sensing-based spatial mapping of physi...

The status of reefs in Palk Bay and the Gulf of Mannar was studied during April-May 2016 following a bleach alert, as the sea surface temperature recorded a sudden increase from 30.5C to 34.0C in Gulf of Mannar. About 71.48%  8.9% of the corals in Palk Bay and 46.04%  3.78% in Thoothukkudi group of Islands in Gulf of Mannar were found bleached,...

The status of reefs in Palk Bay and the Gulf of Mannar was studied during April–May 2016 following a bleach alert, as the sea surface temperature recorded a sudden increase from 30.5 deg C to 34.0deg C in Gulf of Mannar. About 71.48% +/- 8.9% of the corals in Palk Bay and 46.04% +/- 3.78% in Thoothukkudi group of Islands in Gulf of Mannar were foun...

Densely populated coastal zones of India are highly exposed to natural environment. These are impacted by episodic natural events, continuous coastal process, gradually rising sea levels and coexisting human interventions. The present study is an attempt to assess the implication of the sea level rise and coastal slope in the coastal erosion for en...

Globally coastal areas are vulnerable to disasters such as tropical cyclones where 40 % of the global population lives within 100 km of coast. In India, about 13 % of the population live within this coastal belt and hence they are vulnerable to cyclone disasters. The East Indian coast is mostly affected by tropical cyclones originating from norther...

In this paper we demonstrate the persistence of sea surface thermal fronts based on the frequency of Sea Surface Temperature gradient satellite data, at seasonal and non-seasonal cycles. Prominent thermal fronts were observed in the northeast Arabian Sea between the 50 m bathymetry contour and continental self break (∼200 metre contour). A total of...

Coral bleaching reported in the North Bay, Andaman Islands during the April last week of 2016 due to thermal stress. The Coral Bleaching Alert System (CBAS) a service providing by Indian National Centre for Ocean Information Services (INCOIS) has reported the warning and the bleaching has been confirmed from the field survey conducted on April 26,...

The study mainly deals with the physical vulnerability of eastern coast India, Andhra Pradesh. It is one of the Indian states which have a very vast coastal line. Andhra Pradesh is very important to the whole economy, Vishakhapatnam is a major port situated in the eastern coast of India. Andhra Pradesh coastal line about 972 Km long, is affected by...

North Arabian Sea experiences massive proliferation of variable algal species. The study presents variability of Noctiluca and its association with hydrographic parameters such as sea surface temperature (SST) and water column stability using ten years of satellite data. The area was categorized into three regions, North (23 to 26°N and 56 to 70°E)...

Present study employs reef-up approach to map coral reef zones along the Sentinel Island of Andaman using high spectral resolution offered by hyper spectral imagery by Hyperion mission of NASA. This data consisting of 242 spectral bands, provide a unique ability to identify Coral substrate based on their spectral properties. We applied atmospheric...

Coastal areas of Andhra Pradesh in the north eastern part of India are mostly vulnerable for accelerated erosion hazards. Along the 200 km of coastline most of the coastal areas, towns and industries are threatened by reoccurring of storms, flood events and sever coastal erosion. The east coast of India is mostly affected by tropical cyclones origi...

Coastal areas of Andhra Pradesh in the north eastern part of India are mostly vulnerable for accelerated erosion hazards. Along the 200 km of coastline most of the coastal areas, towns and industries are threatened by reoccurring of storms, flood events and sever coastal erosion. The east coast of India is mostly affected by tropical cyclones origi...

Coastal areas of Andhra Pradesh in the north eastern part of India are mostly vulnerable for accelerated erosion hazards. Along the 200 km of coastline most of the coastal areas, towns and industries are threatened by reoccurring of storms, flood events and sever coastal erosion. The east coast of India is mostly affected by tropical cyclones origi...

Coastal areas of Andhra Pradesh in the north eastern part of India are mostly vulnerable for accelerated erosion hazards. Along the 200 km of coastline most of the coastal areas, towns and industries are threatened by reoccurring of storms, flood events and sever coastal erosion. The east coast of India is mostly affected by tropical cyclones origi...

The Indian Tsunami Early Warning Centre (ITEWC) in Hyderabad monitored the 11 April 2012 tsunami off the coast of Sumatra, which was generated by a shallow strike-slip earthquake and it largest aftershock of magnitude Mw (mB) 8.5 and 8.2 respectively, that occurred inside the subducting slab of the Indian plate. The earthquake occurred at 08:38 UTC...

A minor tsunami of about 50 cm was generated along the coast of Qurayat near Makran subduction zone in the Arabian Sea due to the 24 September 2013 Pakistan earthquake of magnitude 7.6 Mw(mB), although its source was ~200 km far inland of the Makran trench. The real-time sea-level observation network in the Arabian Sea recorded minor tsunami arriva...

A minor tsunami of about 50 cm was generated along the coast of Qurayat near Makran subduction zone in the Arabian Sea due to the 24 September 2013 Pakistan earthquake of magnitude 7.6 Mw(mB), although its source was ~200 km far inland of the Makran trench. The real-time sea-level observation network in the Arabian Sea recorded minor tsunami arriva...

Current study emphasizes on recent very severe cyclonic storm Phailin of category -5 hurricane has caused significant morphologic changes in Olive Ridley sea turtle nesting ground in estuarine region of Rushikulya, east coast of India. In the present study, we have used Remote Sensing and GIS tools for investigating and quantifying the morphologic...

An archipelago island system of Andaman is consisting of several hundreds of islands. The coastal environs of these islands are rich in bio-diversity. Most of the islands rimed with fringing corals and healthy mangroves observed near the creeks/streams in the coastal zones. The Sumatra Earthquake occurred on December 26, 2004 recorded a 9.3 Mw not...

Export Date: 13 March 2014, Source: Scopus, Article in Press

The present work is a multi-temporal satellite based study on the spatial dynamic of an important coastal habitat, the Pichavaram mangrove ecosystem, over a period of 15 years. The Pichavaram mangrove forest near Chidambaram, South India is the second largest mangrove forest in the world. Unsupervised classification, the Iterative Self Organising D...

Aftermath of the Indian Ocean Tsunami of December 26, 2004, which caused approximately 230 000 fatalities, the Ministry of Earth Sciences (MoES) has taken up the responsibility to establish the National Tsunami Early Warning System at Indian National Centre for Ocean Information Services (INCOIS), Hyderabad. The Indian Tsunami Early Warning System...

The Intergovernmental Coordination Group for the Indian Ocean Tsunami Warning and Mitigation System (ICG/IOTWS) was formed in response to the tragic tsunami on December 26th 2004, in which over 230,000 lives were lost around the Indian Ocean region. The Intergovernmental Oceanographic Commission of UNESCO (IOC-UNESCO) assembly, during its twenty-th...

The study area coastal zone of Nellore district is experiencing frequent inundation by natural disasters. The current study is focused on generating Multi-hazard vulnerability map using the parameters historical storm surge heights, future sea level, future shoreline and high resolution coastal topography. The area is experiencing the severe coasta...

The coral reef of Andaman Sea is one of the least explored regions of the Indian Ocean. The coral reefs are the tropical fauna forming the important eco-system in the tropical ocean. The coral reefs grow in the suitable climatic conditions. The coral reef systems of Andaman region are unique from ecological perspective. The reefs found around A...

Coastal areas of Orissa State on the northeastern part of the Indian peninsula are potentially vulnerable to accelerated erosion hazard. Along the 480-km coastline, most of the coastal areas, including tourist resorts, hotels, fishing villages, and towns, are already threatened by recurring storm flood events and severe coastal erosion. The coastal...

Aftermath Dec26, 2004 the Boxing Day tsunami, the Indian government had formulated tsunami warning system for Indian Ocean to monitor and forecast tsunamis. The Indian tsunami early warning centre at Indian National Centre for Ocean Information Services (INCOIS), Hyderabad is made operational for 24 X 7 basis from 15 October 2007. The Decision Supp...

Aftermath Dec26, 2004 the Boxing Day tsunami, the Indian government had formulated tsunami warning system for Indian Ocean to monitor and forecast tsunamis. The Indian tsunami early warning centre at Indian National Centre for Ocean Information Services (INCOIS), Hyderabad is made operational for 24 X 7 basis from 15 October 2007. The Decision Supp...

Aftermath Dec26, 2004 the Boxing Day tsunami, the Indian government had formulated tsunami warning system for Indian Ocean to monitor and forecast tsunamis. The Indian tsunami early warning centre at Indian National Centre for Ocean Information Services (INCOIS), Hyderabad is made operational for 24 X 7 basis from 15 October 2007. The Decision Supp...

Aftermath Dec26, 2004 the Boxing Day tsunami, the Indian government had formulated tsunami warning system for Indian Ocean to monitor and forecast tsunamis. The Indian tsunami early warning centre at Indian National Centre for Ocean Information Services (INCOIS), Hyderabad is made operational for 24 X 7 basis from 15 October 2007. The Decision Supp...

Chlorophyll-a maps derived from IRS-P4 Ocean Color Monitor (OCM) was used to study the distribution pattern of phytoplankton biomass in the eastern Arabian sea off Karnataka-Goa coast, southwest coast of India. The data was compared with in-situ measurements of chlorophyll-a concentration estimated for 100 stations covering an area of more than 400...