ABDUL WAHAB KHAN | NT
The obstruction caused to the sea waves by the casino vessel Lucky Seven, that was grounded at the Miramar beach, besides the stationed restroom container there, could be one of the reasons for conditions which have led to drastic sand erosion at the popular beach, and experts say that the bad weather which battered the beach has also caused the worst erosion witnessed for at least last fifteen years.
A prominent wave cut scarp is noticed indicating that the dune is eroded severely.
The height of the scarp is about 1.4 metres and extends to around 50 metres along the shoreline. Wave cut scarps indicate marine erosion.
According to a marine expert, although Miramar beach is prone to and indeed witnesses erosion during June-July every year, the kind of overall erosion observed at Miramar this year (June- September) is unprecedented over at least the last 12-15 years.
A former NIO scientist and member of Goa State Bio-diversity Board (GSBB) Dr Antonio Mascarenhas told ‘The Navhind Times’ that it is rather difficult to state whether the erosion described above was caused by the grounded ship alone as there were other factors like bad weather, erection of watch tower, and restroom container besides flattening of sand dunes, however, a detailed study will able to reveal the exact cause.
“The monsoon was still active during the last week of September. Wind speeds were around 25 km/h, and waves were of the order of 1.5 metres. Such oceanographic parameters induce seawater to come over the beach and attack the base dunes. Being composed of unconsolidated sand and fragile nature, the dunes collapse due to continuous wave onslaught,” he said.
But one of the worst affected areas is the popular Miramar beach, which just fortnight ago saw around 50 metres of marine erosion, said Mascarenhas.
He further said that during high tide on 27 September last month, seawater was touching the base of the eroded dune. Such a phenomenon indicates that the beach got eroded and its level was lower than normal, as a consequence of which the seawater transgressed the available beach, and reached the base of the dune. The vegetation which is crucial to the survival and stability of sand dunes also got uprooted.
The Miramar beach extends about 4.5-km southwards up to Caranzalem and terminates against the wooded hill slopes of Cabo promontory and the sand dunes formed are of low to medium height.
It is further noted that the tourism watch tower is located precisely at the spot where it should not have been, and this is one of the causes why Miramar sand dunes are being routinely damaged.
“This is violation of CRZ rules by the government department. This structure along with the numerous trips their jeeps make over and across the dune field is damaging the sand dunes,” said Mascarenhas, who is also a former member of Goa Coastal Zone Management Authority.
Mascarenhas, who has done an extensive research over a period of five years on sand dunes, said that the eroded dune can be restored by beach nourishment.
“The wind-blown sand collected daily from the roundabout can be transported by hand carts and dumped along the damaged dune on a daily basis, over a month or so. This sand will easily stabilise if ipomoea’ creepers are planted,” he explained.
He further suggested that the sand dunes should be protected by erecting a minimum 1 metre high wooden or geo-textile fence perpendicular to the direction of prevailing winds, and fixing dune plants, wherever upper portions of the beach have no vegetation, that serve as sand traps.