protective sheet on hill slope

protective sheet hill slope bukit batok hillside park prevent soil erosion landslides singapore tropical asia rainforest jungle steep land degradation environmental damage natural hazard trees woods woodland plants road west avenue two equatorial climate hot humid wet sunny vegetation mass movement fragile topsoil ridge human modification protection measure mitigation repair control giant large huge big cover exposed bare surface roadside pavement sidewalk fringe perimeter foliage canopy interaction interrelationship