Mapping Philippine Vulnerability to Environmental Disasters

The Philippines is prone to various climate/ weather-related hazards because of its location in the tropics, along the path of typhoons, monsoons and El Niño-La Niña.

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

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

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

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. Cavite
6. Sorsogon
7. Laguna
8. Biliran
9. Batangas
10. Pangasinan
11. Masbate
12. Metro Manila
13. Tarlac
14. Nueva Ecija
15. Northern Samar
16. Aklan
17. Capiz
18. La Union
19. Western Samar
20. Romblon

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

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. Misamis Occidental
8. Sarangani
9. Zamboanga Del Sur
10. South Cotabato
11. Zamboanga Del Norte
12. North Cotabato
13. Sultan Kudarat
14. Siquijor
15. Tawi-tawi
16. Negros Oriental
17. Camiguin
18. Davao del Norte
19. Misamis Oriental
20. Bukidnon

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:

where

R_C = Risk to Climate/Weather-Related Hazards

R_TY = Risk to Typhoons

R_RC = Risk to Rainfall Change

R_EL = Risk to El Niño

R_TI = 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