MGB-5 investigates the killer landslide in Magallanes, Sorsogon  Effects of Typhoon Dante in mainland Bicol known

The Mines and Geosciences Bureau in Bicol (MGB-V), in coordination with the Provincial Office of the Department of Environment and Natural Resources in Sorsogon and the Municipal Environment and Natural Resources Officer (MENRO) of Magallanes Town, investigated May 4 the reported landslide that occurred in Barangay Hubo, Magallanes Town in the Province of Sorsogon, that buried 18 residents living in the area including 20 houses, the Elementary School, the Barangay Hall and the Day Care Center.

An investigation report prepared by MGB-V showed that the landslide is a debris slump that occurred on May 2, 2009 at 2:30AM as a result of continuous rains for about 4 days triggered by tropical storm Dante.

The heavy rains supersaturated the soil with more than 300 millimeters of rainfall as shown by a rain gauge in Magallanes Town and this triggered the debris slump, the report said.

The report described the width of the landslide as approximately 200 meters wide and with about 25 meters depth. It occurred in the southern slope of a low hill facing Barangay Hubo and slided 150 meters downslope carrying 75,000 cubic meters of silt and clay ending at the edge of the shoreline.

The report has recommended to the Barangay Captain of Hubo and the concerned municipal officials of Magallanes to declare the areas surrounding the low hill where the landslide occurred as uninhabitable. A recommendation was also made to resettle the remaining threatened families.

It will be recalled that as early as two years ago or on November 4, 2006, MGB-V warned  the local government, through a written advisory, that Barangay Hubo is threatened by landslides followed by another verbal warning through the MENRO of Magallanes reiterating the warning after a landslide occurred on 21 February 2008. Two Barangay officials from Barangay Hubo attended on 15 October 2008 the Capacity-Building Seminar on Geohazard Awareness and Disaster Preparedness conducted by MGB-V in Magallanes where the specific hazards in the different  Barangays of the Municipality were discussed and landslide hazard map of the area was given.

Meanwhile, in the aftermath of heavy rains induced by Typhoon Dante, MGB-V immediately conducted a rapid assessment on the effects of Typhoon Dante in the Provinces of Albay, Sorsogon, Camarines Norte and Camarines Sur.

Results of the assessment showed Barangays Gumapia, San Pedro, Buenavista, Gabao, Macawayan, Bagsangan and Tongdol in Irosin; San Vicente, Managa-naga, Aquino, Obrero and Somagongsong in Bulan; Basud in Sorsogon City; Sta. Cruz, Rizal, Burgos and Escuala in Casiguran and Gadgadon in Matnog, all in the Province of Sorsogon; Several Barangays in Libon and Oas in Albay; Baao, Nabua and Bato in Camarines Sur; Labo, Mercedes, San Vicente, Vinzons and Talisay in Camarines Norte were affected by floods.

Like Barangay Hubo, Barangays Osiao in Bacon, Sorsogon City and Lahong in Juban in Sorsogon; Barangays Nogotgot, Inang Maharang, Cawayan and Manumbalang in Manito, Morera in Guinobatan, Salvacion in Sto.Domingo and Lignon Hill in Legazpi City, Maynonong in Tiwi, all in Albay; Sta. Rosa Del Sur in Pasacao, San Isidro and Poblacion in Libmanan, Guijalo and Becalen in Caramoan and Maangas in Presentacion, all in Camarines Sur were affected by landslides.

In the Province of Catanduanes, several landslides occurred mostly along road cuts making most of its central and northern municipalities inaccessible from Virac.