- Related Image
- Click on the image to expand
Eighty-two-year-old fisherman Aliyabba had probably never thought that the house he had built along the coast in Mukkachery, near Ullal in Mangaluru, would one day be eaten by the sea. But it happened in July, when massive tidal waves decimated the structure.
The surging waves tormented 32-year-old Gita Das too, gobbling up her agricultural land in Kendrapara district of Odisha. Mid July, crashing waves brought down a portion of the protection wall around the famous Ganesha Temple at Ganpatipule in Ratnagiri district, Maharashtra. Coastal erosion has reared its ugly head with much greater ferocity than before, shrinking beaches, allowing the sea a greater foothold on land, affecting livelihoods, life and property.
Studies show about 45 percent of India’s coastline is severely eroding, much of it man-made. India’s 7,516 km-long coastline—from the rocky west to the sandy east as well as the islands Andaman and Nicobar and Lakshadweep—has been witness to horrific cases of erosion. “The situation in West Bengal is bad,” claims Prof Sugata Hazra, director the School of Oceanic Studies, Jadhavpur University, Kolkata.
“Already we have lost a lot of islands in the Sundarbans. In the last 40 years, we have lost 120 sq km of land. Some years ago, nine coastal village clusters in Digha had been vacated, with such loss of habitat producing a lot of migrants. Many illegally built hotels in Mandarmuni, a tourist haven, have eroded. It’s as if the sea is taking revenge,” adds Hazra.
The situation is grim in another tourist paradise—Kerala, severely devastated by last month’s floods. Take, for instance, Alappad village in Kollam, a 17-km stretch of land sandwiched between the sea and the enchanting backwaters. Famous for its mineral-rich sand—being mined extensively by companies like Indian Rare Earths and Kerala Minerals and Metals—Alappad might soon vanish from the map. Ponnani and Punnapra share the same fate. According to a study by the National Centre for Earth Sciences, the sea advanced by around five metres every year from 1973 to 2016. While as much as 239.6 km of shoreline has been facing the fury of the tidal waters, Kerala has gained 67.3 metres of land due to accretion.
The situation is depressingly similar on the Konkan coast. The Central Water and Power Research Station in Pune has identified 60 places on the Maharashtra coast, including 12 in Mumbai, which are facing erosion. The famous Deobag beach in Sindhudurg district has reduced to a narrow strip. “If it continues like this, it could adversely impact tourism.
Also, 10 per cent of houses in the village are affected by seawater every year,” shares Mahadev Sakharam, who runs a home stay, a couple of shops and undertakes boat rides. The Maharashtra Shoreline Management Plan 2017 shows how coastal erosion in Dadar, Malabar Hill, Mahim and Versova in Mumbai is posing a threat to infrastructure.
Things are not peachy on the Coromandel Coast either. According to a report by ISRO’s Ahmedabad-based Space Applications Centre (SAC) , if the sea level rises by one metre by 2100, Chennai stands to lose 3.11 sq km of critical industrial infrastructure.
Almost all in the Ennore region with 3,209.33 sq km of Tamil Nadu’s coast is likely to be submerged and millions rendered homeless. “We are being squeezed by a seaward moving city and a land-ward moving tide,” laments Saravanan from affected Urur Kuppam village. The SAC report further states NTECL Vallur, TANGEDCO’s power plants in Ennore, Kamarajar Port’s existing and proposed infrastructure inside the Creek, HPCL and BPCL’s oil terminals, the Minjur desalination plant and portions of CPCL’s petrochemical refinery in Manali will be swallowed by the sea.
Erosion, according to Geography books, is a natural phenomenon. But things go awry due to human intervention. Dr KS Jayappa of Mangalore University and an expert on the subject explains: “In Karnataka and Kerala when the south-west monsoon strikes between June and September, the wind activity is high which in turn produces huge two-metre high waves generating tremendous energy. As the latter hits the shore, the sediments from the beach is scooped up and taken offshore. After the monsoon, the wave energy decreases gradually and sediments get replaced on the beach. But trouble looms when human activities disrupt this occurrence.
For instance, sand being mined relentlessly in the estuaries leads to a lot less sediments via the rivers making its way to the beaches.” The same problem persists on the deltaic coastlines too. “All the deltaic regions such as the Sundarbans, the Krishna, Godavari and the Mahanadi have been starved of sand which used to be redistributed along the coast by the long shore current. But dams, barrages and diversions being built upstream trap the silt,” says Hazra.
When the confluence points of rivers get closed in the absence of dredging, it impacts the carrying of sand by the rivers to the sea. Prof Kali Sahu of the Marine Science Department of Berhampur University in Odisha says the Ganjam coast receives its sand deposits due to the south-north wind, but on account of the closure of the confluences of the Rushikulya and Bahuda rivers, the drifting of sand by the rivers has almost stopped. Also, rampant deforestation has opened avenues to drift the deposits of the beaches, resulting in erosion, he adds.
Like Karnataka and Kerala, monsoons pose a challenge in Goa, with sandy beaches having a tendency to erode. Says Antonio Mascarenhas, retired researcher from National Institute of Oceanography, Goa: “In fair weather, the sand comes back and beaches refill themselves, gaining their original profile. Problems occur when we interfere with this natural process. From September to January, hastily erected beach shacks in north Goa impede the natural activity, with sand dunes destroyed to aid in their construction. So, when the monsoon waves climb further up the beach, without the protection of the dunes, the sea waves climb further onto land.”
Tropical cyclones, which the east coast is vulnerable to, also dramatically increase the effects of coastal erosion. According to the National Institute of Ocean Technology, of the 974-km Andhra coastline, 210 km have been identified as danger zones. Says former chief scientist of National Institute of Oceanography VSN Murthy, “During the 1970s, it was a different scenario. Now the currents are stronger and during monsoons the tidal height is four metres.”
Dr Surendra Thakurdesai, head of the Geography Department at Gogate-Jogalekar College in Ratnagiri, has studied the phenomenon of coastal erosion on the Maharashtra coast. “Earlier the damage to the coasts during monsoon used to get corrected in the later months. That pace of correction has reduced and hence the damage done is more of permanent nature nowadays,” he says.
Rising sea levels is another problem. The beautiful Pentha beach and other potential tourism spots such as Agaranasi, Hukitola, Eakakula, Madali and Habalikothi in Odisha are bearing the brunt of sea erosion. “The combination of the rising sea level with the change of the wind pattern causing high waves and prolonged coastal erosion has taken a heavy toll on the coastal population,” says Hemant Rout, an environmentalist and the president of the Mangrove Conservation and Marine Turtle Protection Society of Kendrapara, Odisha.
The coastal ecosystem is fairly fragile and tinkering with it in a haphazard manner has heightened the problem. Says environmentalist Aurofilio Schiavina, co-founder of Pondicherry Citizen’s Action Network (PondyCAN): “Very often the coastal protection measures themselves trigger a new cycle of erosion, with many of them designed for a localised problem ignoring the larger problem of erosion. For instance, sea walls and groynes accelerate the process disrupting as they do the natural movement of sand. So when you build a sea wall, you protect that stretch but the neighbouring stretch gets affected.”
Poorly conceived coastal development and construction has led to the erosion of many beaches in Kerala, Tamil Nadu and Puducherry. “All you can see in these places are ugly seawalls made of boulders or concrete. Puducherry is a classic example.
The town’s entire four km-long seafront eroded away due to the construction of a fishing harbour. Attempts to mitigate this erosion by building a seawall aggravated the situation, and has caused a chain reaction of more erosion, which is now eating away Tamil Nadu’s beaches north of Puducherry,” shares wildlife and conservation filmmaker Shekhar Dattatri whose public service video, ‘India’s Disappearing Beaches: A Wake up Call’, is available on YouTube.
National Centre for Earth Science Studies director K K Ramachandra calls ports, harbours as well as groynes culprits. “When constructing a groyne or breakwater, erosion is seen on the northern side while accretion takes place on the southern side,” he says.
There are success stories too. Like for instance the beach in Puducherry which disappeared when a harbour came up in 1986. But thanks to organisations such as PondyCAN and other citizens, which forced the government to not turn a blind eye to the problem, a 300-metre stretch of beach has slowly been formed. “It’s just a small portion of what we have achieved,” says Aurofilio. To protect and conserve the most important and dynamic buffer between the land and the sea, let everybody fight the good fight. The tiny Union Territory just did.
With inputs from Harsha, Abhijit Mulye, Sisir Panigrahy, Ashis Senapati, Krishna Chaitanya, Sri Lakshmi Muttevi, Manoj Viswanathan
How to arrest the erosion
❖ Ensure availability of sand and natural processes of tide acting on the beach to nourish it and redistribute sand. Sea walls or groynes, which involve high investment, are effective only as a short-term measure. For civil engineering solutions, enlist the help of naval engineers. —Prof Sugata Hazra, Jadhavpur University, Kolkata
❖ The trend in the international scientific community is to go for soft engineering measures working hand in hand with nature—hybrid solutions like in the case of hard structures, using material that can be easily dismantled. —Aurofilio Schiavina, Pondicherry Citizen’s Action Network
❖ A green wall such as growing casuarinas curbs wind activity. Vegetation such as Ipomoea biloba, a creeping vine that spreads like a mat, helps bind the sand. —Dr KS Jayappa, Mangalore University
❖ The main case of degradation of the beach dune system in Goa is tourism. Instead of flattening the beach, construction could be done behind the dunes. Why can’t tourists walk 100 metres to the beach? —Antonio Mascarenhas, formerly with National Institute of Oceanography
❖ Mumbai Transformation Support Unit has proposed using geobags—a sand and water mix. Experts claim they can break the flow of the waves from half a metre to four metres.