Towards a secure nation: how safe are we against cyclone-induced sea surges?

Abstract

Several severe tropical cyclones have hit Sri Lanka in the past century, with those in 1964 and 1978 being the worst, resulting in loss of lives of the order of several hundred as well as considerable damage to housing and other infrastructure due to both the sea surge and the high winds. In comparison, the death toll in Sri Lanka due to the tsunami disaster in December 2004 was of the order of several tens of thousands, however, a tsunami event of such magnitude is extremely rare, expected only once every several centuries. So, tropical cyclone induced storm surges appear to pose a more frequent, albeit comparatively less severe, threat of flooding in most parts of the coastline of Sri Lanka than tsunami. Nevertheless, it must be noted that the severity of the storm surge hazard could be greater even compared to the tsunami for certain parts of the coastline of Sri Lanka. For example, the city of Mannar and the nearby localities are probably more at risk of coastal flooding due to storm surges than tsunami. So, whilst improving our tsunami preparedness in coastal areas, we must also pay due attention to the potential threat of coastal flooding due to cyclone induced sea surges as well. How can the country prepare itself for a severe cyclone event? As far as sea surges are concerned forecasting of storms, early warning and evacuation are necessary to save lives. Furthermore, as in tsunami mitigation, public education and awareness is also an important aspect in storm surge hazard mitigation as well. So, it is prudent to integrate the tsunami hazard with cyclone induced sea surges as part of a multi-hazard risk reduction strategy.