Design Guidelines for Vegetative Approach Application to Mitigate Riverbank Landslides in Mangkang Wetan and Mangunharjo Villages, Semarang Coastal Area, Indonesia

Abstract

The Semarang coastal area is vulnerable to floods, land subsidence, and landslides, including Mangkang Wetan and Mangunharjo villages. The community villages struggle with flooding every year because of the riverbank landslides. The government’s efforts to improve the critical embankments have not yet reached these villages. The community prevents landslides by a conventional method, such as using sacks filled with sand. However, this effort did not make it significantly effective. Therefore, this study proposes a vegetative approach as an alternative effort to reduce the landslide possibility and provide directions for riverbank management. This approach emphasizes soil conservation by applying a suitable plant type to reduce the landslides possibility. Determining the design guidelines for the vegetative approach starts by analyzing the physical condition of the village and the river to specify zone types; then continues by analysis of the appropriate vegetation types. Afterward, determine the design direction for each zone and recommend a suitable type of vegetation. The analysis results show two strategies related to the possible application of a vegetative approach. The do-nothing strategy is for locations that cannot physically intervene because there is no river border. In contrast, the do something strategy is applied to locations that physically allow for a vegetative approach at the river border. However, no single effort can prevent landslides, so it needs to combine mechanical and vegetative approaches that adjust to the physical characteristic of the river and the soil type.