"The causes of the landslide in Ponorogo are quite complex," Bagus Bestari Kamarulah, a member of a swift study team, stated here, Tuesday.
Based on a brief study conducted by the team, other factors are the gradient of the cliff and the composition of the rocks, he noted.
The area is highly prone to landslides, as the gradient of the cliff is 60 degrees.
On the slope of Gede Cliff, the local people have planted ginger and bamboo plants.
"These types of plants are not suitable for cliff areas. They should be planted below the cliff," he remarked.
Moreover, the high precipitation had also caused the landslide. Incessant downpours had lashed the cliff for three days prior to the landslide.
The study was conducted in cooperation with the National Disaster Mitigation Agency (BNPB) and the Center of Volcanology and Geological Disaster Mitigation.
The landslide buried 35 homes, and 28 people went missing.
The BNPB has warned the local villagers to anticipate more landslides, as further rains are forecast to fall in the area in the current rainy season.
The study indicated that the village is at risk of landslides, Tri Budiarto, deputy in charge of disaster emergency mitigation at the BNPB, pointed out.
The team also found cracks on the right and left sides of the Gede Cliff in a radius of up to 150 meters from the landslide spot.
Of the 28 missing victims, only three bodies have been found so far.
Bad weather, mostly heavy rains, had hampered the search efforts.(*)