MAGELANG-Coming to the rainy season, along people around Kali Putih river in Jumoyo, Magelang, are expected to remain alert to the possibility of cold lava flooding. This is due to the fact that areas affected by cold lava flood some time ago have not been improved. In fact, some dikes and river channels along Kali Putih have experienced many physical changes, both the direction and condition due to landslide and erosion due to mining activities.
"In principle, the people have to remain alert to the danger of cold lava flood. When heavy rainfall occurs, the flood could be more severe than earlier because the affected areas have not been improved," an expert of UGM Geology, Ir. Bambang Widjaja Hariadi said, at a coordination meting on Cold Lava Flood Anticipation in Kali Putih, at the residence of head of Jumoyo village, Wednesday (28/9).
Bambang emphasized that the areas affected by cold lava flood will be still potentially exposed. In addition, if the rocks up and around Mount Merapi, which have hardened and exposed to heavy rain, will possibly cause greater impacts and damages.
"If the rain up there is heavy, it will become more damaging because the material is greater," Bambang added.
In line with Bambang, a staff of the Volcanology Technology Development and Research Agency (BPPTK) Yogyakarta, Ir. Dewi Sri Sayuti appealed the people along Kali Putih prepare themselves since now particularly the start of rainy season on the twentieth day of October as estimated by Meteorology and Geophysics Agency (BMKG).
"Although people should be ready and vigilant, they don’t need to panic," Dewi said.
In front of residents and volunteers who attended the meeting, Dewi explained that since September 15th, status of Mount Merapi is normal and shows no hazardous volcanic signs. Dewi gave an overview of the potential for Merapi lava which will pass through Kali Putih as much as 8.2 million m3. Kali Krasak is 10.8 million m3, Kali Gendol 24 million m3, Kali Pabelan 20.8 million m3, and Kali Woro 7 million m3.
"Although the potential is smaller than some other rivers, lava flooding in Kali Putih should still be a concern because the condition is different from that in other rivers," she explained.
On that occasion, Dewi also said that there is still potential threat of Merapi cold lava flood, especially in the upcoming rainy season, early warning system both by society and the technology needs to be prepared better.
Previously in the event, a data analyst of BMKG Yogyakarta, Mardiyanto, S.Si., M. Si explained that the prediction is that the start of rainy season in Jumoyo and surroundings is the twentieth of October. BMKG predicts future rainfall is still normal because the impact of global phenomena such as La Nina and El Nino does not affect it.
The event coordinated by Jumoyo Village Head, Sungkono is one step to anticipate the impact of flooding as well as to answer the concerns of local residents, especially in the upcoming rainy season.