Manila Observatory (2005) Philippine Risk Assessment Maps. http://www.observatory.ph/vm/risk_maps.html

Risk = Risk = Hazard x Exposure x Vulnerability

Geophysical Risk

Earthquake Risk: Since 1968, PHIVOLCS has recorded twelve destructive earthquakes in the . This record includes the infamous July 16,1990 earthquake which caused innumerable injuries and at least 1,100 deaths. Seismicity (geographic and historical distribution of earthquake events) is all over the country except in the region.

The top ten provinces that are at risk to earthquakes are: 1. Del Sur 2. 3. 4. 5. 6. 7. Ifugao 8. Oriental 9. 10.

La Union and Pangasinan are prone to earthquakes, especially the deep-focused ones, due to the Trench while and have earthquake hazards due to Philippine Trench and nearby active faults. Frequency of shallow and left-lateral strike-slip earthquakes in Nueva Vizcaya, Nueva Ecija, Eastern Pangasinan, Benguet and La Union can be attributed to its location along the Philippine Fault Zone.

However, Ifugao, despite having less earthquake occurrences is at risk because of its very high vulnerability to disasters.

Earthquake-induced Landslides Risk:

Most of the provinces, except Palawan, are susceptible to landslide hazards. The top ten provinces that are at risk to earthquake-induced shallow landslides are:

1. Ifugao 2. Del Sur 3. 4. Benguet 5. 6. 7. 8. 9. Davao Oriental 10.

Ifugao, and Sarangani ranked high because of their high vulnerability to disasters while Rizal ranked the lowest. Benguet, despite its low vulnerability, ranked four because of its high exposure factor or population density. Aurora ranked higher than Davao del Sur and Davao Oriental despite its low vulnerability compared with the other two provinces. This is due to the fact that the whole of Aurora is more susceptible to landslide than the other two provinces.

Volcanic Eruptions Risk:

Philippines lies within the Ring of Fire, a region of subduction zone volcanism surrounding the Pacific Ocean. This explains the distribution of most volcanoes in the Philippines. In 1991, Mt. Pinatubo eruption was well known to be the most violent eruption in the 20th century. Philippine Volcanoes are classified as Active, Inactive and Potentially active. Twenty-two (22) historically active volcanoes are distributed all over the archipelago.

Since volcanoes are not present in some provinces, these particular areas have no risk to volcanic eruptions. The top ten provinces at risk are:

1. 2. 3. 4. 5. 6. 7. South 8. 9. 10.

Camiguin has the highest risk because the land area is so small such that a volcanic eruption can affect the whole province. Sulu ranked second because it has the most number of active and potentially active volcanoes.

Tsunami Risk:

In November 14,1994, a 7.1 magnitude earthquake in triggered a tsunami that left at least 41 persons dead, mostly children and old people.

Most of the coastal areas have experienced a tsunami or have a tsunami hazard potential. The top ten provinces that are at risk to tsunamis are:

1. Sulu 2. Tawi-tawi 3. 4. Batanes 5. 6. 7. 8. 9. Camiguin 10. .

Sulu and Tawi-tawi took the top two seats because of their high potential for tsunami owing to their location between two nearby trenches namely, Sulu Trench and Cotabato Trench. Moreover, both provinces are also densely populated and have very high vulnerability. Similarly, most areas in Basilan and Romblon are at high risk especially because they have been previously affected by a tsunami. (PHIVOLCS)

Climate and Weather Risk.

Risk to Projected Temperature Increase.

The areas most at risk to temperature increase during the projected 2080 climatology are and Central .

The top 20 provinces at risk to projected temperature increase are:

1. Sulu 2. Basilan 3. Lanao Del Sur 4. 5. 6. Davao Del Sur 7. Del Sur 8. Tawi-tawi 9. Occidental 10. Camiguin 11. Siquijor 12. 13. 14. Del Norte 15. 16. Albay 17. Sarangani 18. Oriental 19. 20. Ifugao

Projected Rainfall Change Risk:

The map of risk to projected rainfall change shown below incorporates both rainfall decrease during the dry season and rainfall increase during the wet season. The areas most at risk to projected rainfall changes are Central, South and Southeast Luzon and Eastern Visayas.

The top 20 provinces at risk to projected rainfall change are:

1. Albay 2. Pampanga 3. Ifugao 4. Rizal 5. 6. Sorsogon 7. Laguna 8. Biliran 9. 10. Pangasinan 11. Masbate 12. 13. Tarlac 14. Nueva Ecija 15. Northern 16. 17. 18. La Union 19. Western Samar 20. Romblon

Typhoon Risk:

Northern Luzon, Southeastern Luzon and Eastern Visayas are the areas highly at risk to the occurrence of tropical depressions, tropical storms, typhoons and super typhoons.

The top 20 provinces at risk to typhoons are:

1. 2. Albay 3. Ifugao 4. Sorsogon 5. 6. Sur 7. 8. 9. Mountain Province 10. Camarines Sur 11. 12. 13. 14. Pampanga 15. La Union 16. Nueva Ecija 17. Pangasinan 18. Masbate 19. Tarlac 20. Western Samar

El Niño Risk:

Areas highly at risk to El Niño-induced drought are Central and West Mindanao.

The top 20 provinces at risk to drought are:

1. Sulu 2. Basilan 3. Maguindanao 4. Lanao Del Sur 5. Lanao Del Norte 6. Davao Del Sur 7. 8. Sarangani 9. 10. 11. Zamboanga Del Norte 12. North Cotabato 13. 14. Siquijor 15. Tawi-tawi 16. 17. Camiguin 18. 19. Misamis Oriental 20. Bukidnon

Combined Geophysical Risk Map:

Combined Climate- and Weather-Related Risk:

The aforementioned process for computing for risk was performed to map the risk to projected rainfall change, risk to projected temperature increase, risk to typhoons and risk to El Niño-induced drought. A composite risk map portraying the combined risk to all these climate- and weather-related disasters was obtained by summing all the risk scores, as in the equation below: RC = RTY + RRC + REL + RTI where

RC = Risk to Climate/Weather-Related Hazards RTY = Risk to Typhoons RRC = Risk to Rainfall Change REL = Risk to El Niño RTI = Risk to Temperature Increase

The results were again normalized within a 100-point scale.

Summing the four individual risk scores reveals that the areas most at risk to climate- and weather-related risks in general are Southeastern Luzon and Eastern Visayas. This indicates that the risk to typhoons and risk to projected rainfall change dominate the sum. The lower composite risk scores of Mindanao likewise indicate that although Mindanao has higher risk to temperature increase and El Niño- induced drought compared to other areas, the difference in the scores is not large.

The top 20 provinces at risk are:

1. Albay 2. Pampanga 3. Ifugao 4. Sorsogon 5. Biliran 6. Rizal 7. Northern Samar 8. Cavite 9. Masbate 10. Laguna 11. Batangas 12. Sulu 13. Western Samar 14. Nueva Ecija 15. Tarlac 16. Pangasinan 17. Basilan 18. Metro Manila 19. Camarines Sur 20. La Union

Exposure-related Details:

Vulnerability-related Details

Gross Value Added in Agriculture, Fisheries, and Forestry by Region (1999)

Poverty Gap:

Human Development Index (2000).

Provincialized Human Development Indices of the year 2000 was obtained from the Philippine Human Development Report 2000 published by the UNDP and HDN. HDI encompasses health, education and income factors. The inverse of the HDI represented the vulnerability score.

Important Findings Across Map Categories

National-scale mapping does not only serve to point out priority areas, but it also aids in the identification of trends and themes across map categories that can be potentially correlated. Comparative spatial analyses of maps yield commonalities and patterns that illuminate directions for further study.

1. COMBINED DISASTER RISK MAPS a. Climate- and Weather-Related Maps

Among the climate- and weather-related risk maps, the Risk to Typhoons map and the Risk to Projected Rainfall Change map have areas of Central Luzon and the Bicol region in common as high to very high risk areas. On the other hand, the area that ranks high to very high in risk in both the Risk to El Niño and Risk to Projected Temperature Increase maps is Western Mindanao.

The Combined Risk to Climate Disasters map represents the sum of the normalized, provincialized risks to typhoon (super typhoons, typhoons, tropical storms and tropical depressions), drought caused by El Niño, projected rainfall change and projected temperature increase. The top ten provinces are: Albay, Pampanga, Ifugao, Sorsogon, Biliran, Rizal, Northern Samar, Cavite, Masbate, and Laguna. In general, Central Luzon and the Bicol regions rank high to very-high on the risk scale. This indicates that it is the risk to typhoon scores and risk to projected rainfall change scores that dominate the summation of risks. In the case of the risk to El Niño scores and risk to projected temperature increase scores, the gap in the scores is between the highly-ranked provinces and the rest of the country as not as great as with the other two maps. b. Geophysical Maps

The maps of areas at risk to earthquakes and earthquake-induced landslides have certain areas of Central to Northern Luzon and Eastern Mindanao in common. However, there are areas like Bukidnon and Lanao that have a high risk to landslides but a low risk to earthquakes, indicating that there must be other factors contributing to the occurrence of landslides in these areas. Areas at risk to both tsunamis and volcanic eruptions include the northwest to southeast diagonal across RP. Given this similarity, the identification of factors that can correlate volcanic eruptions and tsunamis can be subjected to further study.

The Geophysical Disaster Risk Map represents the sum of the normalized, provincialized risks to earthquakes, earthquake-induced shallow landslides, tsunamis and volcanoes. The top ten provinces include: Sulu, Camiguin, Ifugao, Davao Oriental, Sarangani, Benguet, Surigao del Sur, La Union, Lanao del Sur, and . In general, Central Luzon and Eastern Mindanao are the high-ranking areas.

2. ANTHROPOGENIC MAPS IN CONJUNCTION WITH DISASTER RISK MAPS a. Land Use Map i. Versus Climate Risk Map: areas in central Luzon, Bicol Region and Sulu islands that rank very high on the combined risk to climate disasters map are primarily agricultural areas and coconut plantations. Thus, climate disasters pose a risk not only to lives but also to livelihood. There is a need to measure the risk of climate disasters to livelihood. ii. Versus Geophysical Risk Maps: very high risk areas in central Luzon and eastern Mindanao are plantations and dipterocarp forests, which also serve as a source of livelihood. Together with the slope map, it may be advisable to further study the effect geophysical disturbances on livelihood in these regions. b. Gross Value Added and Disaster Risk The GVA maps represent an alternative method for quantifying the effect of disasters on livelihood. Comparative analysis shows that areas at low risk to disasters like Palawan are also those with high GVA. These maps can further be correlated with maps of ecological resources to ascertain of these areas rank high on the GVA solely due to the low occurrence of disasters or due a combination of factors such as low occurrence of disasters coupled with available ecological resources. c. Heirarchy of Urban Centers Map i. Versus Climate Risk Map: Provinces with the highest risk in central Luzon are also those with the most urban centers. Assuming that most resources, telecommunication and transportation facilities are concentrated in urban centers, the vulnerability of these regions can be reduced (hence, reducing risk). In future risk maps, there is a need to factor in (1) the capability of each urban center to respond to disasters, and (2) the surrounding provinces' access to urban centers quantified by location, slope, roads, transportation and communication. ii. Versus Geophysical Risk Map: The effect of having urban centers within high-risk areas is a double-sided issue. On the one hand, urban centers can better respond to, for instance, medical needs in a time of disaster. On the other hand, if the disaster in question is an earthquake or a landslide, then the presence of many infrastructures within an urban center may actually compound the hazard. Collapsing buildings, ground liquefaction and the like are the collateral hazards of having an earthquake in an urban center. Since the available resources and infrastructures differ from one urban center to another, it is advisable to carry out future risk analysis on a local scale.

3. ECOLOGICAL MAPS IN CONJUNCTION WITH DISASTER RISK MAPS a. Integrated Marine and Terrestrial Priorities Map Temperature and precipitation are said to be two major indicators of climate. Certain areas highly at risk to projected temperature increase and rainfall change are also rank highly on the map of marine and terrestrial priorities. It becomes relevant, therefore, to determine how the projected climate change may potentially affect the country's ecosystems, particularly in areas of high marine and terrestrial priority. These maps can further be correlated to the map of socio-economic pressures to determine in which areas the effects of climate change may be potentially aggravated. Factors like changes in population and land use may affect the priority rankings of marine and terrestrial resources. b. Groundwater Availability Comparing the map of groundwater availability to the map of risk to El Niño shows that areas in Mindanao which are most at risk to induced drought actually possess productive aquifers that can possibly mitigate the effects of El Niño. c. Slope and Forest Cover This map can be correlated to the map of landslides in the sense that areas with steeper slopes are expected to be more at risk to landslides. It has been hypothesized that the presence of forest systems, although beneficial in preventing excess runoff and flash floods during a typhoon, may actually contribute to the occurrence of landslides due to the sheer weight of the vegetation. d. Mapping Ecological Disaster Risks Mining activities have historically been known to contribute towards water pollution. The map of mines shows that several mining activities are located near major river basins or within critical watersheds. The R=HEV framework can be used to map the risk of water contamination due to mining activities and other such ecological disasters. It must be noted however, the occurrence of ecological disasters may be closely correlated the geophysical and climate and weather-related disasters which may act as triggering mechanisms.