Baseline Assessment: Vulnerability Assessment of Northern Sierra Madre Natural Park Philippines Biodiversity and Watersheds Improved for Stronger Economy and Ecosystem Resilience (B+WISER) Program 22 June 2015 This publication was produced for review by the United States Agency for International Development. It was prepared by Chemonics International Inc. The Biodiversity and Watersheds Improved for Stronger Economy and Ecosystem Resilience Program is funded by the USAID, Contract No. AID-492-C-13-00002 and implemented by Chemonics International in association with: Fauna and Flora International (FFI) Haribon Foundation World Agroforestry Center (ICRAF) The author’s views expressed in this publication do not necessarily reflect the views of the United States Agency for International Development or the United States Government. Vulnerability Assessment of Northern Sierra Madre Natural Park Philippines Biodiversity and Watersheds Improved for Stronger Economy and Ecosystem Resilience (B+WISER) Program Implemented with: Department of Environment and Natural Resources Other National Government Agencies Local Government Units and Agencies Supported by: United States Agency for International Development Contract No.: AID-492-C-13-00002 Managed by: Chemonics International Inc. in partnership with Fauna & Flora International (FFI) Haribon Foundation World Agroforestry Center (ICRAF) 22 June 2015 CONTENTS List of Figures ............................................................................................................... ii List of Tables ................................................................................................................ iii List of Plates ................................................................................................................. iii Acronyms ..................................................................................................................... iv Rationale ....................................................................................................................... vi The Northern Sierra Madre Natural Park ..................................................................... 1 The Climate Profile ........................................................................................................ 3 Baseline Climate .................................................................................................... 3 Climate scenario for Isabela in 2020 and 2050....................................................... 5 Assessment Framework and Methodology ................................................................. 7 Data Collection....................................................................................................... 7 Vulnerability Assessment ....................................................................................... 7 Hazards Assessment ............................................................................................. 9 Flood Hazard Assessment .................................................................................... 9 Drought Hazard Assessment .............................................................................. 11 Landslide Hazard Assessment ............................................................................ 12 Land Capability Classification .............................................................................. 13 Generation of Soil Erosion Potential ................................................................... 14 Rainfall Factor (R) ............................................................................................... 15 Soil Erodibility Factor (K) ..................................................................................... 15 Slope Length and Slope Gradient Factor (LS) .................................................... 16 Creation of Soil Loss Tolerance .......................................................................... 17 Determination of Soil Erosion Index .................................................................... 17 Generation of Land Capability Classification ....................................................... 17 Validation ............................................................................................................. 18 Findings ....................................................................................................................... 21 Hazards Assessment ........................................................................................... 21 Flood Hazard Assessment .................................................................................. 21 Drought Hazard Assessment .............................................................................. 31 Landslide Hazard Assessment ............................................................................ 40 Land Capability Classification .............................................................................. 49 Protection Areas .................................................................................................. 49 Key Biodiversity Areas ......................................................................................... 49 Stream Buffer Areas ............................................................................................ 50 Production Areas ................................................................................................. 51 Multiple Use Zone ................................................................................................ 51 Limited Production Zone ...................................................................................... 52 Unlimited Production Zone .................................................................................. 52 VULNERABILITY ASSESSMENT OF THE NORTHERN SIERRA MADRE NATURAL PARK, ISABELA | i Conclusion .................................................................................................................. 56 Recommendation ........................................................................................................ 57 References ................................................................................................................... 58 LIST OF FIGURES Figure 1. Location of the Northern Sierra Madre Natural Park .................................................. 2 Figure 2. Climatic type of the Northern Sierra Madre Natural Park in Isabela Province ........... 4 Figure 4. Framework of the vulnerability assessment ............................................................... 8 Figure 5. Framework for erosion-based land capability classification system ......................... 14 Figure 6. Sites visited during the validation ............................................................................. 20 Figure 7. Flood susceptibility based on CNCM3 model observed scenario in the Northern Sierra Madre Natural Park ......................................................................... 26 Figure 8. Flood susceptibility based on CNCM3 A1B scenario (2020s period) in the Northern Sierra Madre Natural Park ......................................................................... 27 Figure 9 Flood susceptibility based on CNCM3 A1B scenario (2050s period) in the Northern Sierra Madre Natural Park ......................................................................... 28 Figure 10. Flood susceptibility based on CNCM3 A2 scenario (2020s period) in the Northern Sierra Madre Natural Park ......................................................................... 29 Figure 11. Flood susceptibility based on CNCM3 A2 scenario (2050s period) in the Northern Sierra Madre Natural Park ......................................................................... 30 Figure 12. Standardized precipitation index based on A1B scenario in Isabela Province ........ 32 Figure 13. Standardized precipitation index based on A2 scenario in Isabela Province ........... 32 Figure 14. Drought vulnerability based on CNCM3 model observed scenario in the Northern Sierra Madre Natural Park ......................................................................... 35 Figure 15. Drought vulnerability in 2020s period based on CNCM3 A1B scenario in the Northern Sierra Madre Natural Park ......................................................................... 36 Figure 16. Drought vulnerability in 2050s period based on CNCM3 A1B scenario in the Northern Sierra Madre Natural Park ......................................................................... 37 Figure 17. Drought vulnerability in 2020s period based on CNCM3 A2 scenario in the Northern Sierra Madre Natural Park ......................................................................... 38 Figure 18. Drought vulnerability in 2050s period based on CNCM3 A2 scenario in the Northern Sierra Madre Natural Park ......................................................................... 39 Figure 19. Rain-Induced landslide susceptibility based on CNCM3 model observed scenario in the Northern Sierra Madre Natural Park ................................................ 44 Figure 20. Rain-Induced landslide susceptibility based on CNCM3 A1B scenario (2020s period) in the Northern Sierra Madre Natural Park ................................................... 45 Figure 21. Rain-Induced landslide susceptibility based on CNCM3 A1B scenario (2050s period) in the Northern Sierra Madre Natural Park ................................................... 46 Figure 22. Rain-Induced landslide susceptibility