Building Coastal Resilience in South Asia against Extreme Events

Authors: Dr. M.V. Ramana Murthy, Flora Bawi Nei Mawi, Sourav Kumar Biswas and Khayal Trivedi

According to a 2020 report by the UN, more than 7000 extreme events have been identified since 2000 resulting in a sharp increase in floods and droughts globally. With the accelerating climate change, warmer weather, and frequent marine heatwaves, our coasts are particularly at a greater risk of facing frequent flooding, soil erosion, and loss of agriculture and natural defense systems that have been protecting us since centuries. Continuing the discussion on building coastal resilience, HOISA conducted a panel discussion with expert panelists from the subcontinent to chart a way ahead.

Dr MV Ramana Murthy from the National Centre for Coastal Research, Ministry of Earth Sciences India highlighted that over the last century and particularly since 1950, we have been witnessing a global trend of decrease in the number of rainy days, and an increase in intense rainfall events of 10-15 cms of downpour per day. The situation is alarming as it causes more destruction to crops, infrastructures and livelihood with flash floods and soil erosions. This can be seen in the heavy downpour in Mumbai on 26 July 2005 with 944 mm of rainfall in 24 hours and in Chennai on 1 Dec 2015 with 494 mm of rainfall in one day. In both these cases, critical data on vulnerable areas, extent of flooding, low lying areas and early warning systems were missing.

Researchers are currently working a model called INFLOWS that gathers all information related to the urban infrastructure and coastal population by using various models to then predict the potential inundation areas, thereby providing sufficient time for early warning systems. With an increase in extreme events, we require a two-fold approach – both short term and long term to strengthen our existing infrastructure along with an efficient warning system to build the much necessary coastal resilience.

Coastal resilience implies building the ability of a community to bounce back after hazardous events such as hurricanes, coastal storms, and floodings, instead of simply reacting to impacts. Over the coming decades, the population of India's Coastal regions and cities is expected to further increase. Coupled with the potential impacts of climate change, coastal communities, homes, infrastructure, and ecosystems are staring at increased disaster risk. The recent trends in the Arabian sea are particularly worrying as we are witnessing increased cyclonic systems, depressions and wave power on the coasts. Further the coasts are also under heavy stress with increased development of ports, coastal structures, damming of rivers and dredging of tidal inlets.

To counter these challenges, the National Shoreline Assessment System is building a database of Shoreline change atlas for the entire Indian coast using 12 sets of satellite images (1990-2018). This data is being updated annually, and state wise to identify vulnerable hotspots and thereby provide solutions.

There are various coastal management strategies at play today such as: Managed Realignment - where a new line of defense is identified inland; Move seawards – where new defenses are constructed towards the sea; and Limited interventions – where adjustments are made to be able to cope with erosion or inundations. It is recommended to look towards sustainable solutions that are cost-effective responding to the nature ecosystem in the area. However, it must be noted that a mixture of strategies may be required depending on the context and the community being affected. As examples, Chellanum in Kerala saw a construction of flood barriers on the coast line which worked in its favour as there has been no flooding since three years. Ramaypatnum in Orissa on the other hand required a very minimal intervention to protect the coastal communities. Pondicherry employed a strategy that is mimicked from the Lakshadweep where the wave power is broken while creating a beach at the coast. A living shoreline with natural habitats such as the mangroves, enhance and protect the coast.

As we look forward into the future, an informed and prepared community will have a greater opportunity to bounce back from disasters. Resilience should be measured by the information a community possesses. This allows better decision-making, lower carbon footprint, and improved citizen response in times of crisis.

Opportunities and Challenges of Nature-Based Solutions

Sourav Kumar Biswas from Sponge Collaborative shed light on the opportunities and challenges of nature-based solutions in the current context of increased risk or cyclones, storm surges and flooding resulting in coastal erosion, ground water and saltwater intrusion and habitat loss.

While looking at nature-based solutions, strategic conservation or restoration of mangroves, coral reefs and dunes can comprehensively mitigate all dimensions of risks linked to multi-hazards. These solutions can be prospective, wherein natural landscapes are protected, they can be corrective where natural or hybrid systems are leveraged (planting mangroves, reef restoration etc) or they can be compensatory, where bioeconomy and blue economy are promoted (agroforestry, sustainable fisheries, eco-tourism).

An analysis by the Council on Energy, Environment, and Water (CEEW) suggests that three out of four districts in India are extreme event hotspots for flood, drought and cyclones. More than 95% of coastal Indian districts are prone to extreme events. In such a scenario, discussing different solutions become imperative.

The South Asian coasts can particularly learn from the three cases laid out as below.

Marshall Islands are deeply at risk with the rising sea levels. With only about 0.5m sea level rise, 8.5% of the buildings in the Marshall Islands are at the risk of inundation. The same climbs up to 37.1% with 1m sea level rise and 92.4% with 2m sea level rise. In such a scenario, seawalls are a common response to mitigate flooding, however, they may not withstand the future sea level rise with a risk of increased erosion, wave overtopping and scouring processes in the reef. Nature-based and hybrid solutions can particularly help in such cases where we must not only protect the shoreline by building coastal structures to limit intrusion but also strengthen reef bed to ensure a natural protection barrier against waves. Long term climate adaptation in coastal areas is about pursuing multiple adaptation pathways to prepare for different climate scenarios. Avoiding maladaptation and figuring out which strategies receive adequate investment is the biggest challenge we are facing.

On the other hand, the Tampa Bay in Florida, shows the opportunities but also challenges of Nature based solutions. The bay has a diverse coastal and nearshore ecosystem. With various natural and constructed coastal conditions, they face varying degree of exposure to sea level rise. The present coastal systems including of dunes, seagrass, mangroves, salt marsh and wetland forests all play are very critical role in its protection. The sea level rise coupled with urban land use and human activity are a challenge to this ecosystem. This is where we must protect, restore, enhance and deconstruct to build coastal resilience.

And lastly, in the case of Dhanushkodi in Tamil Nadu, we can see how integrating the blue economy agenda in building coastal resilience can help its ecosystems. Coastal eco-tourism, sustainable agriculture, salt extraction, fisheries and mariculture, and climate resilient settlements and ports form part of the agenda. Currently Dhanushkodi is facing challenges in health, nutrition, education, agriculture, financial inclusion, and skill development. Due to its geographical position, Dhanushkodi can be leveraged as a tourism destination within a diverse ecosystem and home to community of fishermen and salt pan workers. Developed salt marshes, a pilgrimage corridor, coastal uplands and reefs, and coastal lagoons can together create a framework for development of its community as well as of the ecology of Dhanushkodi against future threats.

These examples show that depending on the case, its socio-cultural-ecological context, different methods may be adapted to build coastal resilience. While nature-based solutions form an integral part of all these strategies, we must think of hybrid solutions to better defend our coasts while ensuring a sustained development of coastal communities.

A perspective from a community-based organisation

Flora Bawi Nei Mawi, co-founder and director of Community Care for Emergency Response and Rehabilitation in Myanmar, contributed to this panel by highlighting the importance of bringing communities at the center of all policy changes and transformation. From their previous experience of dealing with cyclones and storm surges, they believe that the main actor in bringing solution to a crisis must be the community itself. When the humanitarian sector or government, labels a particular group as vulnerable who need constant help, they are othering them by not allowing them to empower. The act of coming together, community memory and experience, collective response, decision making, and learning are essential in building resilience and recovering from any man-made or natural disaster.

Resilience means taking the space, claiming the rights of accountability, shifting the power to community, generating data and interpretation, and collaborating with others with mutual respect. Flora recommends that we must allow for stronger local leaderships, accountability, and abolishing aid hierarchies by addressing the underlying problem in part, if not all.         

While a long road lays ahead in strengthening the South Asian coasts from increased risks of climate change, we must continue to exchange information, ideas, strategies as each of the panelists highlighted while adapting hybrid solutions from bottom-up and top-bottom to ensure a thriving shoreline that the regions is blessed with.                                                                                                                                                                                                      

Contributions by Dr. M.V. Ramana Murthy, Sourav Kumar Biswas, and Flora Bawi Nei Mawi. Edited by Khayal Trivedi