By Danny O. Calleja
LEGAZPI CITY, Aug. 12 – The Mines and Geosciences Bureau (MGB) has announced that copies of geohazard maps of the seven Bicol cities and 83 of the region’s 107 municipalities are now available for use by local government units (LGUs) as inputs in disaster risk reduction and land use planning.
The maps were prepared under the Geohazard Mapping and Assessment Project (GMAP) as part of the Bicol Recovery Project implemented through a partnership between the Department of Environment and Natural Resources (DENR), MGB’s mother agency, and the Department of Social Welfare and Development (DSWD).
The project was designed to enable the poor and vulnerable groups, especially women and children, to prepare and cope with the impacts of disasters and various environmental emergencies, according to Reynulfo Juan, MGB’s regional director for Bicol.
All the maps of different geohazard themes such as landslide susceptibility, flood hazard, liquefaction potential and ground subsidence/ground settlement prepared by the MGB could be obtained from its regional office at the Bicol’s regional government center in Barangay Rawis here, Juan said.
Local government and barangay officials will be trained on how to use the geohazard maps for disaster preparedness, he added.
GMAP was a countrywide undertaking started late last year for a funding of P3.56 million with the DSWD footing P1.89 million and the rest amounting P1.67 million coming from MGB fund.
For Albay, the geohazard maps of this city and that of Tabaco and Ligao Cities are already available along with that of the towns of Camalig, Daraga, Guinobatan, Malinao, Malilipot, Tiwi, Rapu-rapu, Jovellar, Manito, Oas, Libon, Pioduran and Polangui.
The three cities and the towns of Camalig, Daraga, Guinobatan, Malinao and Malilipot have some of their barangays listed as floods and lahar flow because of their proximity to Mt. Mayon with others sitting within the permanent danger zone.
The other towns far from the volcano have their own risk factors such as Tiwi that plays host to the 350-megawatt geothermal energy complex being run by Chevron; Rapu-rapu, an island town where the Korean-owned Rapu-rapu Minerals, Inc. (RMMI) operates a polymetallic project through open-pit mining and Manito, site of the 110-megawatt geothermal field of the Energy Development Corporation.
Oas, Libon and Polangui also listed as flood-prone areas being part of the Bicol River Basin (BRB), a vast wetland covering various towns of Albay, Camarines Sur and Camarines Norte.
In Camarines Sur, those towns mapped as geohazard areas are Baao, Balatan, Bato, Bombon, Buhi, Bula, Cabusao, Calabanga, Camaligan, Canaman, Caramoan, Gainza, Libmanan, Magarao, Milaor, Minalabac, Nabua, Ocampo, Pamplona, Pasacao, Pili, Sagnay, San Fernando, Sipocot, Siruma and Tinambac, all within the BRB.
The other Camarines Sur municipalities are Lupi, Ragay and Del Gallego that are called the railroad towns of mountainous terrain whose forest covers have perished due to logging and other environmental-destructive activities.
The rest listed are Buhi, Garchitorena, Goa, Lagonoy, Presentacion, San Jose and Tigaon, all upland-coastal areas threatened by floods and landslides.
The cities of Naga and Iriga that are also flood-prone being parts of the BRB are also listed.
In Camarines Norte all the 12 towns—Daet, the capital town; Jose Panganiban, Labo and Paracale, the mining towns; and Basud, Talisay, San Lorenzo Ruiz, Vinzons, Capalonga, San Vicente, Sta. Elena, Mercedes all, mountain areas pestered by illegal logging are geohazard sites, according to the MGB mapping.
In Sorsogon, the maps ready are for the City of Sorsogon, the provincial capital and for 11 of the province’s 14 towns namely Bulan, Bulusan, Barcelona, Casiguran, Castilla, Gubat, Irosin, Juban, Magallanes, Matnog and Sta. Magdalena. All these LGUs have portions that are considered risk areas.
The whale shark town of Donsol that is being visited by thousands of tourists coming for interactions with whale sharks, the world’s largest fish and its adjoining municipality of Pilar that is considered the main gateway between the mainland of Bicol and the island province of Masbate are considered risk free being not listed in the geohazard sites.
Down Masbate, the mapped risk areas are the city which is the provincial capital, the gold- mining town of Aroroy and the municipalities of Cataingan, Balud, Cawayan, Dimasalang, Placer and Uson, all within the province’s mainland.
For Catanduanes, those mapped geohazard sites are the mountainous towns of Gigmoto, Pandan, San Miguel and Viga, all bearing records of massive landslides that have killed several residents and damaged millions of pesos worth of properties and government infrastructures.
Albay Governor Joey Salceda whose province is frequented by massive floods and landslides particularly when huge volumes of volcanic debris stored at the slopes of Mt. Mayon are swept down to the lowland by rainwater, hailed the project saying it will help towards sound disaster risk management that requires vital information on the geographic distribution of risks.
Juan said that with one of the world's longest coastlines and archipelagic features, the Philippines is naturally prone to geological hazards.
Coastal areas are especially prone to coastal erosion, storm surges and sea level rise. Under the project, coastal areas spanning 2,385 kilometers and 160 municipalities nationwide were also surveyed, Juan said.
The DENR and MGB believe that identifying such areas will reduce the loss of lives and properties brought about by natural disasters.
Juan explained that the program was designed not just to anticipate disasters but also to help people adapt to the geologic effects of climate change.
He said that climate change has also affected the severity and frequency of natural disasters.
In recent years, many have suffered losing their properties and loved ones because of sudden landslides and floods. Suffering resulting from these tragedies could have been avoided if people had been warned earlier, Juan said .
GMAP, he explained makes use of remote sensing studies to identify features that could indicate unstable areas or impending physical events. These remote sensing studies use air photographs, LandSat and Earth Resources Technology Satellite (ERTS). Radar images are used as well.
Data are also gathered through field surveys by geologists from MGB. These are stored, processed and managed under a Geographic Information Systems (GIS) platform.
Information based on geographic location can be captured, stored and retrieved using the GIS platform. GIS can also be used for displaying information in form of layers of digital maps, Juan said.
The digital version of the geohazard maps, being prepared will be similar to the satellite imagery provided by the National Aeronautics and Space Administration ( NASA). The map will contain various layers of images outlining the Philippines’ topographical, geological and coastal features.
Juan said that with the information becoming accessible, people will find out for themselves, with the help of experts and scientists, whether or not they are in affected areas, and whether they need to adapt to these geographic features to avert disastrous results.
“Time is truly of the essence in disaster management. MGB has been given up to the end of this year to complete the digital versions of the maps,” he added. (PNA)