Lake Cliff Landslide Mitigation – A Case Study of Lut Tawar Peusangan Lake, Aceh, Indonesia

Landslide is one of the most common natural disasters in Indonesia. In Lut Tawar Lake, specifically the cliff side, the landslide event occurs almost daily. Mitigation effort becomes a necessity following the fatality cases it causes. This study aimed to identify landslides and suitable mitigation for the case of Lut Tawar’s lake cliff. A combined approach of landslide survey and image interpretation with field validation was used. In addition, local vegetation surrounding the case area was identified from the survey and interview process. The results showed there are in total 37 landslide points in the study area. The conducted analysis showed the landslide was mainly caused by land use change from forest to a plantation, slope, particularly in the cliff area that was carved for road development, the volcanic geology of Bukit Barisan mountain, rainfall intensity, and the equatorial rainfall characteristic of the study area. The results also suggest the finest solution for landslide mitigation, namely the eco-engineering approach, a revegetation method using the local vegetation. Local vegetation comprises multiple strata, of which grass in the below strata, shrubs in the middle strata, and trees in the upper strata, constitute a shield for the lake cliff. Within this structure, government and community can cultivate these plants in the surrounding lake area.