Valuing the impacts of the projected sea level rise due to global warming on coastal resources: a case study in Cavite City [Philippines]

This study tried to determine the extent of vulnerability of the Philippine coastal areas to sea-level rise focusing on Cavite City, and to identify adaptation strategies being practiced in the study area. Over the past decade or so, Cavite City has been vulnerable to tropical cyclones, flooding, coastal erosion and saltwater intrusion. This study also tried to estimate the economic vulnerability of the two most vulnerable barangay [villages] to flooding due to a one-meter SLR by 2100, namely: Barangays 11 (Lawin) and 48-A (Narra A). Results showed that by 2100, a one-meter SLR will cause damage to about 127 structures/houses with around 1,743 sq m of floor area, and 25,420 sq m land will be inundated Barangays 48A and 11 alone, if no action is taken to protect these infrastructures from accelerating sea level rise. The current value of these capital and land resources was estimated at Php 4,162,289.50 and Php 50,840,000, respectively. Existing adaptation strategies initiated by the local government to protect the coastal barangays in Cavite City building protective structures such as the sea walls and rockwalls, maintaining good drainage canals, and regular cleaning of the drainage canals. The local officials and the residents along the coasts found the structures i.e. sea walls and rockwalls, effective. The cost of the rockwall is estimated at Php 147,456.04 per linear meter. Presently, Cavite City has a total of 805.28 linearmeters of sea wall and 1,617.18 linear meters of rockwalls built around its coastal barangays lying along Manila Bay. For the barangay residents, it is 'business as usual'. Majority of the residents learned to adapt to the situation of flooding without doing anything. For them ankle length water in the streets or in their homes is a usual recurrence and it will just past. However, for the small number of respondents, they adapt to flooding by building higher houses, elevated garage and putting gutters and sandbags around their houses. They approximate the cost incurred ranging from P10,000 to P100,000 in elevating their flooring to building second storey for their houses. Majority of the residents do not intend to leave their present houses even if they continue to experience flooding. There were some residents who are willing to leave their places if the government can provide them relocation. The residents will opt to sacrifice their properties to flooding brought about by sea level rise and storm surge for as long as it is cheaper for them to stay in the present abode than to be relocated. If relocation will be the local government's planned strategy, the costs would be equal to the value of lost buildings/structures, the value of lost lands plus the acquisition cost of properties. The social benefits would be the reduced risk in the lives of the residents knowing the economic vulnerability due to flooding brought about by SLR, the government can plan ahead for their adaptation strategies considering the cost of adaptation strategies and the number of families or households to be benefited when the coastal barangays will be inundated by sea water.