High water

Neglecting natural buffers, Kerala is building walls to keep out the sea

Artificial barriers along Kerala’s vulnerable shore are insufficient to protect the thickly populated coastal areas.

The coast of Kerala, where rain-laden clouds of the southwest monsoon make landfall, is losing its natural edge. Granite blocks and concrete walls now bind much of the sandy beaches, where generations of children played at the edge of the water.

Artificial structures along the Kerala coast cover 301.3 km, which is more than half of the coastline length of 576.1 km in the state. The length of the coastline with some form of erosion (low, medium or high) along with artificial structure measures 370.9 km. This is a little more than two-thirds of the length of Kerala’s coastline.

To complicate matters, the coastal region of Kerala also happens to be among the most populous parts of the country. According to the shoreline change assessment report for Kerala prepared by the National Centre for Sustainable Coastal Management for the federal environment ministry, the state’s coast had an average population density of 2,022 persons per sq km, according to 2001 census data.

This was even then much higher than Kerala’s average population density of 859 persons per sq. km, which in turn is higher than the national average of 382 persons per sq km, according to the 2011 Census.

With significant coastal erosion and high population density, artificial structures continue to be constructed along the coast in Kerala with the stated objectives of protecting lives and property. According to the shoreline change statistics prepared by National Centre for Sustainable Coastal Management for the country, though Gujarat has the longest-eroding coastline (928.4 km out of 2,021.3 km), artificial coasts have been built only over 6.9 km. Even in West Bengal, which has 78.5% of its coast under erosion, artificial structures have been constructed only along 12.1 km.

Limited effectiveness

However, the effectiveness of such walls and similar structures to deal with the adverse impacts of climate change is limited when compared with natural protection such as mangroves and sand dunes. Even while the artificial structures are increasing along the coast, the naturally protective systems are facing increasing pressures to their existence.

Kerala’s coast is vulnerable to sea level rise of 1.75 mm per year, according to estimates by the National Institute of Oceanography. The impact of sea level rise in some parts of Kerala can be significant because of the inundation of the estuarine network along the coast, for instance, in and around the commercial city of Kochi.

The estuarine mouth areas are also highly prone to erosion. Kollam and Ernakulam are the districts with the highest length of artificial coast at 79.92% and 79.74% respectively. These are districts with large backwater systems – Vembanad and Ashtamudi.

“In addition to the sea level rise, it is the increasing intensity of the storm surges that is going to be important for the Indian coast,” R Ramesh, director of National Centre for Sustainable Coastal Management, told indiaclimatedialogue.net

Boost natural protection

The answer, according to Ramesh, is to conserve and protect the natural protection systems such as mangroves, sand dunes, mud flats, sea grass beds and coral reefs. National Centre for Sustainable Coastal Management has mapped the ecologically sensitive areas all along the country’s coasts and submitted to state and national governments for incorporation into the coastal zone management plans as areas that should not be infringed for development.

“Both during the Odisha Super Cyclone of 1999 and the Asian Tsunami of 2004, mangroves have proved to have protected lives and property,” V Selvam, coastal ecologist and executive director of the MS Swaminathan Research Foundation, told indiaclimatedialogue.net

In a communication published in Science journal, Selvam and other international researchers showed how villages protected by mangroves and other coastal vegetation in Tamil Nadu survived the impact of the 2004 tsunami better than those that did not have the same protection.

According to Selvam, mangroves also provide protection against sea level rise because the soil platform under the mangroves plants continues to rise in height. The leaves from the mangrove plants fall into silt trapped from the water, and together the platform continues to rise. This can keep pace with the projected sea level rise and prevent inundation.

Emerging understanding

However, a detailed understanding of how the impacts of climate change will impact the Indian coasts is still emerging. Recently, National Centre for Sustainable Coastal Management completed an exercise for the Ministry of Environment, Forests and Climate Change to map the climate change vulnerability along the coast and also the high tide line. This project was done in partnership with the Survey of India.

“We wanted to identify the areas that are vulnerable if there is a storm surge or a cyclone,” Ramesh said. “We worked out a methodology to find out how much of inundation can happen if there is a surge, say 1 metre or 0.5 metre. The increase in the water level could be due to surges or due to sea level rise. It is important for the governments to identify the low-lying areas and have an action plan on how to protect them in the future.”

The idea was to mark out a hazard line for the coast. There were two components for this. One was the flood line – till what point the sea could come if there was a flood. The second was to understand the erosion along the coast.

For both, it was necessary to have precise information about the elevation profile along the coast. Low-level aerial photography provided high-resolution data. Erosion mapping was done on top of this mapping.

Erosion accretion

For the erosion-accretion maps across the country, National Centre for Sustainable Coastal Management used colour codes so that policymakers could identify in which stretches of the coast the sediments were being washed away or being built up at a low, medium or high rate. The maps also identified the stretches that have artificial structures along them.

“Coasts have a natural dynamic, with erosion and accretion happening at the same place,” Ramesh observed. In summer months, accretion happens because the low energy waves deposit sediments. During the monsoon period storm waves take out these sediments. Sea walls and hard structures usually move erosion to down-drift areas.”

In this process of mapping, the high tide line was also mapped along the country’s coast, so that it could be used as baseline for future coastal zone planning and management. The maps have been handed over the national and the state governments in the coastal states for ground validation and subsequent notification.

The Kerala government has tasked the Thiruvananthapuram-based National Centre for Earth Science Studies to fine-tune these maps along with local-level information inputs, according to an official source. The government is of the opinion that blending local understanding about the coasts will help in effective zoning and management.

Local scenario

At the local level, the sea walls are considered both an asset and a liability. For instance, in Chettuva village of Thrissur district, there is a long sea wall along the coast. PK Basheer, member of the Kadappuram Panchayat, remembers that during his childhood, the sea was further away from where it currently is.

Though the sea wall has helped prevented the sea from coming in further, it breaches often and does not provide a permanent solution. On the other hand, while the tidal currents have been taking away sand from the beach, it has been building a sand bank along the mouth of the Chettuva river, endangering the fishing boats as they come into the harbour.

Ravi Panakkal, an environment activist, finds the sea wall an obstruction to the conservation of turtles along the coast. “Even though much public money is spent to construct this wall, it does not offer protection against storm surges, as the sea has been dislodging the stones at many locations,” he told indiaclimatedialogue.net

K. Venu, a local journalist at Chavakkad, says the sea walls have been failing because they are constructed hastily, have faulty designs and are sited at wrongly identified locations.

Ramesh of National Centre for Sustainable Coastal Management feels that a “sediment cell approach” has to be taken to understand the erosion-accretion dynamics along the coast. Sediments cells are that part of the sea that is enclosed by two headlands (the part of the land jutting into the sea). The flow of sediments happens only within a sediment cell, so thus once the dynamics of this movement is understood then siting and designing interventions such as artificial structures, if required, becomes more scientific.

“We have identified 27 primary sediment cells and 54 sub cells for the entire length of the Indian coastline,” said Ramesh. “We would like to use this as a boundary for the integrated coastal zone management plans.”

It may not be possible for Kerala to abandon the sea walls already built. However, with a holistic and scientific approach, further hardening of the coast with sea walls can be prevented. This will help Kerala’s coast to find its own natural resilience to climate change and eroding seas.

This article first appeared on India Climate Dialogue.

We welcome your comments at letters@scroll.in.
Sponsored Content BY 

What’s the difference between ‘a’ washing machine and a ‘great’ washing machine?

The right machine can save water, power consumption, time, energy and your clothes from damage.

In 2010, Hans Rosling, a Swedish statistician, convinced a room full of people that the washing machine was the greatest invention of the industrial revolution. In the TED talk delivered by him, he illuminates how the washing machine freed women from doing hours of labour intensive laundry, giving them the time to read books and eventually join the labour force. Rosling’s argument rings true even today as it is difficult to deny the significance of the washing machine in our everyday lives.

For many households, buying a washing machine is a sizable investment. Oddly, buyers underestimate the importance of the decision-making process while buying one and don’t research the purchase as much as they would for a television or refrigerator. Most buyers limit their buying criteria to type, size and price of the washing machine.

Visible technological advancements can be seen all around us, making it fair to expect a lot more from household appliances, especially washing machines. Here are a few features to expect and look out for before investing in a washing machine:

Cover your basics

Do you wash your towels every day? How frequently do you do your laundry? Are you okay with a bit of manual intervention during the wash cycle? These questions will help filter the basic type of washing machine you need. The semi-automatics require manual intervention to move clothes from the washing tub to the drying tub and are priced lower than a fully-automatic. A fully-automatic comes in two types: front load and top load. Front loading machines use less water by rotating the inner drum and using gravity to move the clothes through water.

Size matters

The size or the capacity of the machine is directly proportional to the consumption of electricity. The right machine capacity depends on the daily requirement of the household. For instance, for couples or individuals, a 6kg capacity would be adequate whereas a family of four might need an 8 kg or bigger capacity for their laundry needs. This is an important factor to consider since the wrong decision can consume an unnecessary amount of electricity.

Machine intelligence that helps save time

In situations when time works against you and your laundry, features of a well-designed washing machine can come to rescue. There are programmes for urgent laundry needs that provide clean laundry in a super quick 15 to 30 minutes’ cycle; a time delay feature that can assist you to start the laundry at a desired time etc. Many of these features dispel the notion that longer wash cycles mean cleaner clothes. In fact, some washing machines come with pre-activated wash cycles that offer shortest wash cycles across all programmes without compromising on cleanliness.

The green quotient

Despite the conveniences washing machines offer, many of them also consume a substantial amount of electricity and water. By paying close attention to performance features, it’s possible to find washing machines that use less water and energy. For example, there are machines which can adjust the levels of water used based on the size of the load. The reduced water usage, in turn, helps reduce the usage of electricity. Further, machines that promise a silent, no-vibration wash don’t just reduce noise – they are also more efficient as they are designed to work with less friction, thus reducing the energy consumed.

Customisable washing modes

Crushed dresses, out-of-shape shirts and shrunken sweaters are stuff of laundry nightmares. Most of us would rather take out the time to hand wash our expensive items of clothing rather than trusting the washing machine. To get the dirt out of clothes, washing machines use speed to first agitate the clothes and spin the water out of them, a process that takes a toll on the fabric. Fortunately, advanced machines come equipped with washing modes that control speed and water temperature depending on the fabric. While jeans and towels can endure a high-speed tumble and spin action, delicate fabrics like silk need a gentler wash at low speeds. Some machines also have a monsoon mode. This is an India specific mode that gives clothes a hot rinse and spin to reduce drying time during monsoons. A super clean mode will use hot water to clean the clothes deeply.

Washing machines have come a long way, from a wooden drum powered by motor to high-tech machines that come equipped with automatic washing modes. Bosch washing machines include all the above-mentioned features and provide damage free laundry in an energy efficient way. With 32 different washing modes, Bosch washing machines can create custom wash cycles for different types of laundry, be it lightly soiled linens, or stained woollens. The ActiveWater feature in Bosch washing machines senses the laundry load and optimises the usage of water and electricity. Its EcoSilentDrive motor draws energy from a permanent magnet, thereby saving energy and giving a silent wash. The fear of expensive clothes being wringed to shapelessness in a washing machine is a common one. The video below explains how Bosch’s unique VarioDrumTM technology achieves damage free laundry.


To start your search for the perfect washing machine, see here.

This article was produced by the Scroll marketing team on behalf of Bosch and not by the Scroll editorial team.