Philippines: Geohazard mapping to save more lives

by Hazel F. Gloria

The weather is now very unpredictable, climate shifting and always changing causing untold pains, sufferings and death of millions of people around the world.

Families became homeless, unproductive and desperate. There has to be a way out because now, more than ever environmental issues are increasingly becoming important and closely affecting people’s routine patterns.

According to the Department of Environment and Natural Resources-Mines and Geo-sciences Bureau (DENR-MGB), “Geo-hazards Mapping and Assessment Program is an important component of the disaster management and mitigation to reduce the loss of lives and properties brought about by natural disasters.”

Geohazard mapping, the EMB explains identifies various areas that are susceptible to floods, landslides, liquefaction and other ground instabilities such as vulnerabilities to earthquakes.

It also determines possible settlement sites, properties and infrastructures that are most likely to be affected.

Local government units and communities can also use the map for further development plans because it indicates which areas are critical or those outside the danger zones.

Geo-hazard assessment and its importance

Geological Database Information System (GDIS) Supervisor Science Research Specialist Dr. Karlo Queano revealed they have completed the geo-hazard assessment throughout the country in December 2010.

However, there are only 900 or 67% generated maps in 1:50,000 scale because only 8-10 geologists of DENR nationwide are working on the generated maps.

“That's the reason it took us so long to generate those maps. Information is for free and it could be uploaded in the internet,” Queano said.

“After what happened in Guinsaogon, Leyte, where a landslide claimed thousands of lives, we strongly realized the need for geo-hazard mapping,” Queano added.

After that, MGB personnel had to communicate its findings to the barangay officials and taught them how to read the maps.

Communities, LGUs and government agencies involved in disaster relief, mitigation, and risk management were also given landslide threat advisories with the results and recommendations from DENR; capacity-building and formal Information, Education and Communication (IEC) materials to intensify information and vital data relative to disasters and calamities, Qeuano explained.

According to the DENR, local government units (LGUs) have to monitor the disaster prone areas in their respective barangays and implement what MGB recommends.

During rainy season, they can use the hazard map to issue early warning to residents who are living near the critical areas indicated in the geo-hazard map.

Queano cited some problems they encountered based on their experience in the implementation of this program. “Every time, a new elected official is installed, they have to go back to square one --conduct again an orientation and briefing on the important uses of the geo-hazard maps.”

Relative to all these meanwhile, MGB proposes for a permanent position of the National Disaster Coordinating Council planning officer for the continuous implementation of the program.

MGB said, these planning officers will be responsible for the information dissemination of the program to their respective communities.

Another proposal is a standardize 1:10,000 scale maps for geo-hazard assessment in order to get more details and enable community leaders to identify more susceptible areas to reduce disaster risk and calamities to happen.

Understanding the environment thru field assessment

In the meantime, DENR is now coordinating with the Department of Education (DepEd) to discuss how to integrate into the curriculum issues on environment and disaster risk reduction in the secondary level.

The Department of Science and Technology (DOST) on the other hand is currently developing a teachers’ Module that they can use during classes as well as informing other people in the communities.

“Hazards are a natural process and we don't have to be afraid of what's happening in our surroundings we just need to understand and adapt to our environment”, Queano said.

Meanwhile, continuous rains brought about by the Northeast monsoon and tail-end of a cold front affecting Visayas and Mindanao may trigger the occurrence of geological and natural hazards, such as landslides and flashfloods, the MGB warns.

Based on its geo-hazard mapping, MGB-7 has classified to be highly susceptible to landslides portions and areas within the mountain barangays of Cebu City, Balamban, Toledo City, Pinamungahan, Dumanjug, Ronda, Asturias, Catmon, Naga City and Talisay City.

The result of the MGB-7 rapid field assessment with high landslide susceptibility listed nineteen (19) barangays in Cebu City that included Lusaran, Binaliw, Guba, Budlaan, Malubog, Buot-Taup, Busay, Sirao, Taptap, Tagbao, Tabunan, Pung-ol Sibugay,Sudlon II, Sudlon I, Sinsin, Buhisan, Pamutan, Sapangdaku, and Adlaon.

Also in the list are eleven (11) barangays in Balamban, namely; Hingatmonan, Lamesa, Luca, Ginatilan, Cabasiangan, Matun-og, Cansomoroy, Gaas, Magsaysay, Cabagdalan, and Duangan.

Five barangays in Toledo City-- Tungkay, Pangamihan, Bagacay, Loay and DAS; barangay Lamac in Pinamungajan, Cebu and five (5) barangays in Asturias-- Agbanga, Baye, Bairan, Kanluangan and Sak-sak are also named as susceptible to landslides.

Twelve (12) barangays in Catmon; Amancion, Anapog, Bactas, Bongyas, Ambangkaya, Cabungaan, Can-ibuang, Duyan, Ginabucan, Panalipan, Tabili and Tinabyonan and mountain barangays in Talisay City, two 2) barangays in Dumanjug; Doldol, Purok 3 and Brgy. Kang-actol and two (2) barangays in Ronda; Cansalonoy and Vive are also in the rapid field assessment list.

DENR-7 Regional Director Loreto Alburo said, the rapid field assessment covers barangays whether these are located near the shoreline, on foot slopes, mid slopes and/or mountain ridges.

“We should be vigilant at all times especially those communities or residents who are living near or at the foot of the mountain and in low-lying areas as many geo-hazards are rain-induced,” Director Alburo explained.

Lastly, Alburo urged the local chief executives to revisit the landslide susceptibility rating and landslide advisory letter which the DENR issued to them during the rapid geo-hazard assessment so that they will know where landslide or flooding would likely occur within their respective jurisdiction. (PIA-7/HFG)