23 Jan 2019 04:50am IST
How could a group of musicians rollicking on the shores of Indonesia expect they would lose their lives engulfed by a virulent wave? A tsunami had struck. On December 23, 2018, a volcanic disturbance in the Sunda straits triggered a tsunami following which 430 people from the surrounding islands perished. Earlier, in 2010, the Fukushima tsunami in Japan damaged a nuclear plant and flooded a coastal airport. Back home, on December 26, 2004, the coast of Tamil Nadu was swept by giant waves causing 8700 deaths and massive loss of property. In addition, as the incessant hurricanes along the coast of USA, the recurring storm surges along the Indian East coast have resulted in loss of life and collapse of dwellings on a yearly basis. As such, hydro-meteorological phenomena that invariably culminate in coastal disasters are the foremost natural hazards that impact coastal dwellers of the world.
Essentially, it needs to be noted that frontal shorefronts are obviously the most affected in the wake of marine invasions: apart from the landscape and vegetation, habitations and people are battered the most. In Tamil Nadu, loss of life and property was identified only along the frontal strip ranging from 6 to 132m from the dune line; saline inundations were noted up to 862 metres from the dune line. It is within these strips where maximum damage was observed, and where all the 8700 dwellers perished. A similar scenario has been reported following global tsunamis, hurricanes, storm surges, and also in Indonesia on December 23, 2018 where 430 people vanished. By analogy therefore, if these dwellers had to be living farther from the shoreline, all of them would be living today.
It is often argued that the mandatory open spaces as stipulated in the 1991 and 2011 regulations have no scientific basis, and therefore lack justification for their existence. However, a close scrutiny of the dynamics of such spaces reveals that buffer zones are indeed imperative: (a) The ecologically sensitive dune belts along Indian coasts extend far inland; in Goa, these features are identified up to and even beyond 350 metres from the beach; (b) Erosion is prevalent along world’s sandy as well as swampy coasts; around 70% of world’s sandy shores have eroded and retreated over the past few decades; (c) Accelerated erosion is observed along world’s developed coastlines; loss of property is observed wherever coasts retreat; (d) Sandy coasts are bound to withdraw with the impending sea level upsurge; the extent of retreat depends on the gradient of the shore face. Sand dunes are likely to retreat 40 to 400 m per metre of the sea level rise; (e) Geomorphological studies have revealed that the predicted rise in global sea level is bound to cause rapid and extensive retrogression of wetlands, marshes and mangrove swamps; (f) The effective shoreline advance or retreat of a coastal site depends on the global sea level change and local vertical crustal movements; human activities are a complicating factor that can result in coastlines moving landward and thus invading former dry areas; (g) A rising sea level could also result in greater intrusion of saline waters into estuaries with a consequent contamination of coastal aquifers; in large urban areas salt water has advanced several kilometres inland; (h) Global climate change models have forecast increase in intensity of storms and cyclones with associated flooding of coastal lowlands. The most cost effective long term solution for the health of coasts is preserving land to: conserve coasts for posterity, neutralise forces of the ocean, and allow future marine transgressions. Hence the requisite buffer zones, designated as NDZs, in the prevailing 2011 coastal laws.
The new CRZ 2018 rules contain some dreadful schemes. By proposing tourism related activities in the NDZ, precisely within which sensitive and fragile sand dunes are located, the coastal buffer zones have lost their morphological value and scientific significance.
Part 1.9 (i) of the draft stipulates that “sand dunes identified shall be conserved and protected”; Part 1.9 (b) notes that “no developmental activities be permissible except for providing eco-friendly temporary tourism facilities on stilts such as walkways, tents and the like”; but strangely, Part 1.9 (d) warns that “no activities on the sand dunes shall be taken up that would lead to erosion/destruction of sand dunes”. Further, Section 4 (ix) “prohibits dressing or altering active sand dunes”. In contrast, Section 5.3 (g) dealing with regulation of activities in NDZ states that “temporary tourism facilities shall be permissible in the NDZ of CRZ-III areas. Temporary facilities shall only include shacks, toilets/washrooms, change rooms, shower panels”. How can fragile dunes survive under such pressures? There appears no relent by the builders/tourism lobby in particular.
In a scientific paper that appeared in Current Science in 2004, this author had concluded thus: “Therefore, the most ideal low-risk development is the one that recognises coastal geological processes, preserves natural coastal landforms, and promotes coastal afforestation.
A public policy for coastal hazard management, by considering suitable options for adaptation, together with appropriate setbacks in the form of forested natural landforms, may well be the last chance to save coastal lowlands and its inhabitants from the ravages of recurring hydro-meteorological events”. This hypothesis (of 2004) is valid today.
(Dr Antonio Mascarenhas is a former Scientist,