They are at it yet again. After ransacking sandy coasts, they are now targeting coastal cliffs. Amidst the daily reports about hill cutting all over Goa, the cliff at Vagator is severely sliced down to the water line. Some years ago, the Baga hillock was badly mutilated due to cutting of rock faces and excavation at its base. Although the rocky slopes of Vagator were disfigured some years ago, similar incidents are common in Anjuna in particular, Ozrant and Cola in the south. Several coastal cliffs have been disfigured by human action as natural rock morphology has been altered drastically.
A fly-by along the coast of Goa will prove that around 35% of our shoreline is characterised by hard rocky strips with majestic cliffs that drop to the shore line and imposing headlands that jut into the sea. A look from the ocean reveals PreCambrian hard rocks exposed at Tiracol, Vagator, Anjuna, Ozrant, Baga and Aguada, oldest granitic rocks are found along Canacona coast, and laterite sections are seen at Chapora, Dona Paula and Cabo de Rama. A geological section from the base towards the top of the cliff indicates large lithological and compositional variations: (a) From the base (sea level), dark grey coloured quartzites are identified up to around 5-8 metres, (b) softer lateritic and pinkish clayey material is observed above the hard base rocks, (c) loose, fractured and partially weathered hard rocky material is interspersed within the lateritic clay. In brief, although the base rock is very hard and compact, the section above is soft and permeable. It is the top lithological section that makes the cliff particularly prone to landslides.
Irrespective of the vulnerable nature of coastal cliffs, these ecosystems are being urbanised illicitly at a rapid pace: (1) At Vagator, two bulldozers were recently identified at the water line, an unprecedented scene never observed before. A pathway has been cut down into the water. The quartzite base of the cliff is excavated for the sake of a concrete embankment. This part falls between the LTL and HTL and constitutes the intertidal zone and is hence classified as CRZ I. As such, the concrete wall is uncalled for, as it has been built by levelling natural rock along the base of the cliff. (2) At Anjuna, the erstwhile cliff coast has lost its identity. Although this is a highly vulnerable rocky coast, the entire strip is heavily built-up with dense structures, mostly hotels and restaurants, perched at the cliff edge. Massive vertical concrete retaining walls have now replaced parts of the rock face. The base of the cliff is lined with a wide strip of tetrapods over 350 metres along the water line. Robbed of a natural sea cliff, this kind of ill planned concretisation makes Anjuna the most obnoxious portion of the Goa coast. (3) The coasts of Ozrant and Ashvem are again saturated with hotels. A new comer would not believe that cliffs and rocky slopes of yesteryears are now occupied by dense commercial structures and hence heavily urbanised. (4) The rocky hill slopes of Dona Paula, Vainguinim, Oxel and Bambolim are dotted with skyscrapers and private residences. A massive starred resort is seen perching at Dona Paula. Luxuriant vegetation is cleared and replaced by residences. Since this zone is now placed under ODP, half the densely wooded slope is earmarked as settlement, yet another urbanised sector in the offing. (5) Canacona is probably the most exotic of all our cliffs. Although these rocky gradients are free from human interference, few isolated constructions are seen. (6) All this concretisation is happening with impunity in the No Development Zone. The cliff faces and the hill tops come under the mandatory setback where construction activity cannot be permitted. Mutilating of coastal hill slopes are blatant violations of CRZ 2011 notification.
The approaching monsoon wave regime is bound to teach us grave lessons: (A) A narrow patch of marine deposits form a beach along the base of sea cliffs worldwide. This sediment is commonly composed of sand, cobbles and boulders. These deposits provide protection to cliffs against direct wave attack and reduce the rate of erosion. The equilibrium that a cliff base offers has been completely altered at Anjuna and Vagator due to the unwarranted human activity. (B) The concrete embankments will act as hindrances to wave attenuation; waves will thus break further seaward, current patterns will alter, thereby causing a disruption in the littoral sediment movement. (C) Since the sea walls are within the reach of waves, its base will get undermined; their survival is thus at stake. (D) The coast is the site of extraordinary release of wave energy. The present geomorphological configuration of cliffs is the result of slow moulding of the landscape over thousands of years. Any interference along the cliff base and rock face is bound to alter coastal processes whereby monsoonal wave regime will lead to enhanced erosion, deepening of cliff base, narrower beaches, removal of sand, slumping of hill slopes, gravity flows, and even landslides.
The concept of CRZ has ceased to exist along the cliff coasts of Goa. The brutal massacre of vulnerable rock faces tantamount to unprecedented violations of several provisions of CRZ rules. In particular, the Anjuna-Ozrant cliffs is a classic example where the entire sector depicts a concretised sea front and is thus heavily urbanised with chock-a-bloc hotels and dwellings within the NDZ. The Anjuna cliff, with a tetrapod lined base is the ugliest. Vagator is presently under attack. Coastal hill slopes of Dona Paula are already built-up. The magnificent granite cliffs of Canacona coast are next in line. It is relatively easy, for example, to restore an eroded sand dune by nourishing it over time; but if a coastal cliff is concretised, the millenia old natural rocky landforms are lost forever.
(Dr Antonio Mascarenhas is a former Scientist, NIO, Goa)
