MAGELANG – People living along the rivers in Magelang District need to be aware of the possibility of cold lava flood of Mount Merapi. The increasing heavy rainfall around the slope of Merapi causes landslide of volcanic material deposit. Moreover, the sabo dam that acts as cold lava barrier along Senowo River, Apu River, Batang River, Blongkeng River, Trising River and Lamat River have already been filled by volcanic material.
That was delivered by volcanologist of Universitas Gadjah Mada, Ir. Bambang Widjaja Hariadi presenting the survey result in the upstreams around the slope of Merapi, Magelang, on Saturday (11/12).
Very well written article! I would just add that why the coverage is often low-grade, provocative, sensational, emotional, conflicting etc etc.. so to dramatise the news as the stations know Indonesians don’t like to think and process info rationally and logically therefore easily provoked on news coverage from such angles.
The TV stations are selfish by fooling the people and continue to be used as a mean by the powerful to control and mind of people.
Indonesia is physically free from foreign colonisation but is now colonised by our very own people: the rich’s and the powerful’s and they use the same tactics the fore-father used to fight with blood: divide and rule!
That’s why low-grade sinetron is attracts lots of viewers.
As for the long term, he suggested that the government immediately adds sabo barriers. According to Bambang, the current barrier is no longer able to accommodate the volume of volcanic material that exceeds the capacity. "Slowly, material sediment is dredged to prevent silting. Excavation of sand and rock from cold lava is fully intended to improve the income of the community," said the faculty of Geology Department, Faculty of Engineering UGM.
Based on Bambang’s observation, the volcanic material which hit people’s houses in Jumoyo village last week was the materials from previous eruptions, not the recent eruption. This was marked from the boulder and sand found at Jumoyo market. "Most of them are andesite rocks from old volcanic sediment material," he said.
However, Bambang said, the Merapi volcanic ashfall in year 2010 apparently made the water stream into a lump of concentrated mud that can carry large chunks of stones.
Yulianto, the official observer of Merapi volcano at the Babadan post in Magelang, informed that the present lava flood was due to the decrease of rainfall around the slopes of Merapi. "At the peak (Merapi) it is still drizzling," he said.
Rainfall in Merapi continues to be monitored and recorded by the officer. From the recording, it is known that in early December, average rainfall is 20.6 mm per day with 2-3 hours’ duration.
In response, Bambang Widjaja said, if the rainfall at the peak of Merapi reaches above 40 mm per hour with 3 hours’ duration, it will certainly be able to erode all the materials of eruption in year 2010. "Fortunately, such rainfall does not occur at the peak of Merapi," he concluded.