Vulnerability Assessment of Irawan Watershed in Puerto Princesa City, Philippines using the GeoREVIEW Model

Abstract

Vulnerability assessment is a rapid planning and decision–making tool to address issues on the vulnerability of a system and minimize the risk to environmental disasters. Amidst its importance as a requisite for empirical–based strategies for adaptation from the impacts of climate change, applicability of vulnerability assessment models however must be tested across the varying regional conditions of systems before their wide usage. The study was conducted to assess the level of vulnerability of the Irawan watershed in Puerto Princesa City, Philippines due to climate change using the GeoREVIEW model. Secondary data were used for each indicator except for the soil. Soil data were obtained through field sampling. Weights of indicators were determined through pairwise comparisons. All the indicators under the three components of vulnerability were characterized except for the biomass potential due to the absence of forest inventory data of varying periods. Values for each indicator of vulnerability were generated and their equivalent vulnerability scales ranging from 1 to 5 were determined. Ten (10) thematic maps were generated with a 30 m x 30 m resolution. Indicators representing the biological components of the watershed had the highest weight while climatic indicators were rated as the lowest. The overall vulnerability map generated a scale ranging from 1.90 to 2.99 placing the watershed at a moderately vulnerable level within its varying regions with an overall vulnerability point to climate change and anthropogenic hazards of 48.96. Adequate interventions must be developed to avoid further aggravation of the present condition of the watershed due to climate change.