Geologist Suggests Diversion of Water Flow from Giant Landslide Sinkhole in Central Aceh

Aerial photo of the atmosphere of a plantation owned by residents that collapsed on the cross-road of Pondok Balik Village, Ketol District, Central Aceh, Aceh, Tuesday (14/1/2026). ANTARA FOTO/Abiyyu/Lmo/foc

BANDA ACEH - Geologist from Syiah Kuala University (USK) Banda Aceh, Bambang Setiawan suggested that the flow of water be diverted from the area of land movement or landslides in Bah Village, Ketol District, Central Aceh Regency so that the land does not move quickly.

"To deal with this phenomenon in the short term, I suggest diverting the existing surface water flow so that it does not pass through the location of the incident," said Bambang Setiawandilansir ANTARA, Wednesday, February 4.

However, said the lecturer of the Geology Engineering Program at the USK Faculty of Engineering, the diversion of water flow including determining the course of the flow must also take into account the geological conditions in the field.

As is known, in recent months, Aceh has been shaken by landslides in Ketol, Central Aceh Regency, which have formed a giant hole. The hole was initially small in the early 2000s, and has been moving gradually since 2004.

Based on the calculations of the Aceh ESDM Geological Team, the hole continues to grow until today it has exceeded 30 thousand square meters (m²). If compared to last 2021, around 20,199 m², meaning a movement of 10,000 m² in the last five years.

According to Bambang, the natural phenomenon (giant hole) in the Ketol Aceh Tengah area is still a mystery, and further geological research needs to be carried out. Because geologically, this condition has the potential or leads to the phenomenon of sinkhole as a trigger for the emergence of the big hole.

He explained, according to Cameron et al. 1983 (compiler of the Takengon sheet geological map, Central Aceh), there is a Sembuang formation (MPs) in the form of limestone that covers the volcanic rock of the Lampahan unit (Qvl) on the surface.

On the other hand, the volcanic rocks that make up the Lampahan unit also have a high landslide potential, especially on steep slopes.

"The problem will be complicated if the sinkhole phenomenon that triggers the emergence of the giant hole. Because, the technical work to handle the impact of this sinkhole requires effort and requires greater resources than a normal landslide," he said.

"Literally, continued Bambang, a sinkhole can be defined as a condition below the surface resulting from the dissolution of limestone or more commonly known as limestone during the geological period.

Or in other words, a sinkhole is a basin, caused by soil and other materials that collapse into an open hole or cavity below the surface of the ground.

"Sinkholes can usually be distinguished in two models, namely the collapse of the cover layer or the subsidence of the cover layer. The results of the study are expected to conclude the mechanism of the formation of the "giant hole", "he said.

He added, based on satellite image data in 2015, 2021 and 2025, there is an opportunity to continue to expand the giant hole. "Because the satellite image shows the expansion of the hole towards the south or approaching the district road," he said.

Therefore, in addition to short-term solutions with diversion of water flow, and installation of road signs, for long-term handling, further geological studies must also be carried out to conclude the mechanism of the formation of the "giant hole".

"Technical mitigation efforts for long-term handling should refer to the results of further geological research," said Bambang Setiawan.

For information, based on the results of the interim study of the Aceh ESDM Office, the movement of the land there was caused by the material being composed of volcanic tuff from the Geureudong formation (volcanic rock) which is loose, porous so that it easily absorbs water and is saturated with water.

Then, there is a discharge or underground water flow that erodes laterally. The drainage channel can overflow and burden the soil there, especially when the rainy season comes.

Then, the steep cliff condition is almost upright to add to the instability of the slope. As well as being triggered by rain and can also be earthquakes, so that the slope is unstable.