Jakarta – Inadequate drainage system in a former illegal gold mine area in Nagari Sungai Abu, Solok Regency, West Sumatra, is one of the factors that exacerbated the landslide disaster, according to the Head of the Center for Volcanology and Geological Disaster Mitigation (PVMBG), Saturday, September 28.
The disaster, which caused the lives of illegal miners, occurred on Thursday. Head of PVMBG Hadi Wijaya emphasised that high rainfall and a poor water management system accelerated the landslide in the area.
“In addition to high rainfall, the condition of the soil around the mine that was excavated without paying attention to slope stability and poor drainage systems caused rainwater to collect in the excavation area. This accelerated the dissolution of the soil and triggered the landslide,” Hadi said in his official statement in Bandung.
The disaster that occurred at the former illegal mine left 13 people dead and 12 survivors, according to the National Disaster Management Agency (BNPB), Sunday, September 29.
Medium to high ground motion potential
According to Hadi, the Solok Regency area is included in the medium to high ground motion vulnerability zone based on the September 2024 Ground Motion Forecast Map. “This zone indicates that ground movements can occur, especially in areas bordering river valleys, road cliffs, or faults. Strong erosion and high rainfall can reactivate old ground movements,” Hadi explains.
He adds that excavation in mining areas with steep slope angles without adequate shoring increases the risk of landslides. In addition, underground excavation and voids in the ground further weaken the soil structure, making slopes more prone to collapse when exposed to rainwater. Hadi said a good drainage system is important at mine sites to channel rainwater effectively.
Rehabilitating former illegal mining areas is an important mitigation measure, he said. “Former mining areas must be immediately replanted with suitable vegetation to improve the carrying capacity of the soil and reduce the risk of landslides in the future,” said Hadi.
Given the region’s high rainfall intensity, PVMBG asks residents to be aware of the potential for landslides, especially if there is prolonged rain. Officials and evacuation teams are also urged to be careful because the remaining landslide material could trigger new landslides.
PVMBG also encourages the halting of settlement development activities in landslide-affected areas. “The area is very vulnerable, and activities that can disrupt slope stability, such as slope cutting, should not be carried out,” Hadi added.
Supervision of illegal mining also needs to be tightened to avoid similar incidents in the future. In addition, socialization to the community about the dangers of illegal mining and the risk of landslides needs to be improved.
“This disaster reminds us of the importance of better environmental management, especially in disaster-prone areas such as mine sites. Rehabilitation and regulation enforcement must be prioritised to prevent further loss of life,” Hadi concluded. (Hartatik)
