Quantifying Landslide Risk in Bindoy, Negros Oriental: A Barangay-Level Assessment of Hazard, Exposure, and Vulnerability

Abstract

The study determined the landslide hazard of chosen barangays of Bindoy, Negros Oriental, specifically the barangays of Cabugan, Penahan, Manseje, Poblacion, Bulod, Malaga, and Danawan. A simplified quantitative method was employed to assess the degree of landslide hazard based on three main elements: hazard, exposure, and vulnerability. In assessing the hazard element, the study considered the role of terrain slope and rainfall intensity as contributing elements of landslides. Exposure was determined by counting the residential houses within proximity to slopes and other areas prone to landslides. Meanwhile, the vulnerability element focused on residential conditions, particularly the quality of residential structures and the presence or absence of measures to protect slopes such as retaining walls and vegetation coverage. It was found that the barangays have varying levels of landslide hazards. Specifically, Poblacion showed the lowest degree of hazard with 32%, which is relatively safe due to the presence of mild slopes, fewer residential houses close to slopes and other areas prone to landslides, and better infrastructure conditions. Danawan showed the highest degree of hazard with 51%, primarily due to the presence of steep slopes, greater numbers of residential houses close to slopes, and a lack of measures to protect slopes. In general, barangays with steep slopes, high exposure, and low measures of protection were found to be more vulnerable to landslides.