According to catastrophe modeling firm AIR Worldwide Typhoon Nari, aka Santi, made landfall in the Philippines, “as of 18:50 October 11, 2013 UTC (2:50 October 12, 2013 PHT; 14:50 October 11, 2013 EDT), just south of Baler, Luzon, as a Category 1 storm with a central pressure of 975 mb, sustained (10-minute) wind speeds of 120 km/h [75 mph], and gusts reaching 176 km/h.
“A radius of 93 km/h [58 mph] winds extends 90 km [56 miles] from the storm’s center. This area is sparsely populated; the only communities in the vicinity are Baler and Dingalan. Manila has experienced tropical storm-strength winds and intense rainfall is expected overnight. Coastal areas have been warned of possible storm surges, but AIR does not expect significant insured losses from this storm. The heaviest expected damage will likely be from flood, although intense winds are expected overnight. Tropical storm-strength winds have affected Manila and coastal areas are warned of storm surges.”
“The Philippines can experience tropical cyclone activity in every month; Luzon has already experienced significant damage from typhoons in the 2013 season as Typhoon Utor (with wind speeds of 194 km/h) made landfall in early August and a weaker Typhoon Rumbia (with wind speeds of 65 km/h) made landfall in late July,” said Dr. Peter Sousounis, AIR Worldwide’s senior principal scientist. “An average of six tropical cyclones make landfall in the country annually, with another three passing close enough to cause loss. Activity peaks in July and November. Weak currents in the atmosphere move the storms over the islands, resulting in heavy precipitation and flooding. Damage to property in the Philippines is dominated by flood through all but the highest return periods.”
“Nari has tracked over or close to Quirino, Nueva Ecija, Nueva Vizcaya, and Pangasinan. The storm will continue to move westward and be offshore once again within the next couple of hours. Heavy rainfall is expected to continue even after Nari exits The Philippines with totals of 100-200mm expected over the next 18-24 hours, and up to 300mm in mountainous areas. After exiting the Philippines Nari will head into the South China Sea, and make a second landfall in Vietnam sometime late Monday.”
AIR explained that in the Philippines, “lighter materials, such as wood frame with galvanized iron or aluminum roofs, are often used for residential buildings in rural areas. In contrast, urban residential structures are generally made of concrete block with metal roofs, although hollow concrete is also used. Masonry residences and high-rise apartments made of steel construction can also be found in the cities. Masonry is often used for smaller commercial establishments although the majority of all commercial and industrial buildings are reinforced concrete or steel. Building codes are not strictly enforced. In the Luzon area one to two story buildings of mixed construction (concrete and wood) are common.”
AIR said, however, that the situation is somewhat different in Manila, where “high-rise commercial and apartment buildings are generally built to stricter code requirements. In addition, commercial and apartment buildings usually have stronger foundations than residential buildings, and these foundations provide a stronger resistance to flood loads. Flood is much more damaging to the lower floors of a multi-story building and many apartment buildings in Southeast Asia have commercial establishments on the first floor.
“Balconies and sliding glass doors, which are common in apartment buildings, increase the vulnerability to heavy winds. The northern area of Luzon is not heavily insured due to low commercial and industrial activity. The highest amount of insured risk is found in Manila. Cyclone coverage typically excludes loss or damage from flood, tidal wave, high water, or overflow, regardless of whether it is caused by high winds.”
Source: AIR Worldwide