Wednesday, January 18. 2012
by Danny O. Calleja
SORSOGON CITY— There is an alarming state of siltation in the
major river and all its tributaries that serve as receiving ends of volcanic debris swept down by rain waters from the slopes and crevices of Bulusan Volcano, according to the Department of Science and Technology (DOST).
All smaller tributaries of Cadac-an River, the main river system that traverses the municipalities of Juban and Irosin are now heavily silted even as the Department of Public Works and Highways (DPWH) had recently conducted dredging operations, Gerry Asuncion, the DOST provincial chief said here on Wednesday.
The huge volume of lahar and other volcanic debris stored at the slopes of Mt. Bulusan during its series of eruptions starting since about three years ago and cascaded with rain waters into these river system brought about these siltation, said Asuncion as he warned local disaster management authorities and residents against its consequences.
This scenario is very likely to cause overflowing of the river and tributaries and trigger flash floods that could ravage nearby communities particularly these days that La Niña has been dumping heavy rains in the area, he said.
The DOST, Asuncion said has been monitoring the developments taking place in areas surrounding Mt. Bulusan which is still abnormal and presently under alert level which means more ash explosions or even a major eruption may occur anytime even as it has not been manifesting signs toward these events in the past days.
Latest bulleting issued by the Philippine Institute of Volcanology and Seismology (Phivolcs) monitoring station based in Barangay Cabid-an here on Wednesday said “seismic network did not detect any volcanic earthquake during the past 24 hours. Weak emission of white steam clouds 50 meters high could be observed from southeast and northwest vents”.
Alert Level 1 status is strongly reiterated and the public as well local government units (LGUs) affected are reminded that entry to the 4-kilometer radius Permanent Danger Zone (PDZ) is strictly prohibited due to the possibility of sudden steam and ash eruptions.
Civil aviation authorities must also warn pilots to avoid flying close to the volcano’s summit as ejecta from sudden eruptions may be hazardous to aircraft while people living within valleys and along river channels should be vigilant against sediment-laden stream flows and lahars in the event of heavy and prolonged rainfall, it added.
Asuncion said that DOST had come up with the river map of these areas for regular monitoring and have also installed a mechanism to find out the volume of mudflow, its increase and its impacts on these certain identified areas.
“With the heavy siltation of Cadac-an river, the barangays of Tampi, Taboc, Biriran and Binanuahan in Juban have now become highly threatened by floods as heavy downpours have been causing river overflowing which if not given immediate intervention, will also create a greater problem in terms of water supply needs,” he stressed.
Asuncion also explained that they are now devising a water filter out of clay that can be used to filter water and remove the particles of sand and silt to come up with safe water for immediate needs.
With the prevailing situation in Juban and Irosin towns, some highly flood-prone areas should be given attention in terms of clean and potable water supply, he said advising that water filter made out of clay can also be used to remove particles on water affected by the silting.
“This water filter can be used for immediate needs in evacuation centers as part of DOST’s disaster risk reduction mechanism intervention to have access to clear water supply to people in evacuation centers affected by flooding or other calamities,” he said.
“Evacuation centers should be able to use alternative means to provide safe drinking water and this water filter made out of clay can be mass produced so that areas affected by flooding can use these as a means to have clear water supply including for bath and toilet needs,” Asuncion added. (PNA)
- Geologists warn Philippine’s Mount Bulusan volcano becoming increasingly restive (theextinctionprotocol.wordpress.com)
- Mount Bulusan spews ash anew (sorsogonunited.wordpress.com)