Philippines produces 3D flood hazard map

by Imelda V. Abano | @iabano | Thomson Reuters Foundation
Wednesday, 25 September 2013 08:45 GMT

A view of a 3D flood hazard map of Cagayan de Oro, one of the most disaster-prone cities in the Philippines.

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Tool should help improve planning decisions as the country faces worsening climate change impacts

MANILA (Thomson Reuters Foundation) - Devastating floods and heavy rains across the country have prompted the Philippine government to begin producing 3D flood hazard maps to help make better planning decisions about flood risks.

“We consider this new map as relevant especially as a tool to make local land use plans truly based on risk - not only historical risks but future risks based on rainfall scenarios. We cannot be planning long term development based on yesterday's event, but must factor in future climate risks,” said Mary Ann Lucille Sering, secretary of the country’s Climate Change Commission.

The maps, which will provide up-to-date scientific data and analysis on local-scale flooding and climate risks, are being created using 3D technology as part of the Climate Change Commission’s efforts to adapt the Philippines to the impacts of climate change.

They incorporate climate change projections for the years 2020 to 2050, and expected future changes in annual mean temperature and rainfall, as well as humidity, chances of erosion, soil texture, sea level rise and other environmental risks.

The data, laid on top of existing maps, helps highlight areas that could face future flooding, Sering told the Thomson Reuters Foundation.

The map identifies areas most vulnerable to flooding with a gradation of colour - the darker the hue, the deeper the water. For instance, the purple colour in the map shows how high water might rise along the banks of the Cagayan De Oro River if heavy rainfall occurs.

The Climate Change Commission is the sole policy-making body of the Philippines government tasked with coordinating, monitoring and evaluating programmes and action plans of the government related to climate change.

Sering said the new maps, which use three-dimensional realistic mapping techniques, are being created using data from the Department of Science and Technology Project Noah and the National Mapping and Resource Information Authority. The commission also collaborated with the Philippine Atmospheric, Geophysical and Astronomical Administration, the University of the Philippines-National Institute of Geological Sciences and other government agencies.

Sering said that, unlike with earlier maps, the new maps incorporate the current situation on the ground in terms of upstream deforestation, narrowing of waterways caused by siltation, and the location of settlements and development.


The first map produced, over a six-month period, was of Cagayan de Oro, one of the most disaster-prone cities in the country. It will be followed by maps of other major cities in the coming months, Sering said.

She said the map of Cagayan De Oro aims to help the government with flood-control projects and to guide infrastructure plans in the city.

“We want to scale up this initiative and hopefully benefit the entire country as soon as possible. If not, we can start with urban areas especially major cities,” Sering said.

The project is supported by the Australian Government Overseas Aid Program through the United Nations Development Program under the Project Twin Phoenix.

Mario Montejo, secretary of the Department of Science and Technology, told the Thomson Reuters Foundation that the new maps will guide the government in efforts to plan ahead for times of disaster, and to better understand the impacts of climate change in the country.

“We have a serious problem of flooding in the country. Now we have an innovative, interactive map that can help us plan ahead and adapt to hazards and other climate-related risks,” Montejo said.

Fernando Siringan, of the Marine Science Institute of the University of the Philippines, said “updating of maps of the entire Philippines with real-time, high-resolution (mapping) is essential for people who are looking at disasters, climate risks and community resilience.”

According to the national weather bureau, about 20 typhoons hit the country every year, often causing death and destruction. Last year alone, nearly 800 people were killed when Typhoon Bopha hit the Philippines.

The Philippines ranked as the country third most at risk of disasters in the World Risk Report 2012, produced by the United Nations University Institute for Environment and Humanity Security. Its report calculated risks for 173 countries worldwide, measuring social vulnerability, exposure to natural hazards and climate change.

Disaster risk in the Philippines is intensified by a lack of preparedness, and of coping and adaptive capacities at the national and local levels, experts say.

Imelda Albano is a reporter based in Manila.

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