Project News

On May 12th, Mr. Toshiyasu UENO, Expert, Mr. Keiji YOSHIDA, Expert, and others have implemented field investigation about debris flow occurrence around Mt. Merapi.

With the eruption of 2010, it is assumed that almost 140 million m³ of volcanic product has deposited around Mt.Merapi. Along with rainfall, the risk of debris flow is increasing. So far over 200 units of Sabo facilities have been installed and brought some effect for prevention of debris flow. However, at every time of rainfall, debris flows down from the upper stream. Then some disasters have been caused in certain area.

At Gendol River (the south slope of Mt.Merapi) which is covered with a lot of pyroclastic flow deposition, no debris flow has occurred until December, 2010. However, after that the number of debris flow occurrence has increased. When it rained on May 1st, debris flow reached a sand pocket, which is 18 km away from the crater. Some sediment flooded from the sand pocket and caused disaster to houses and farmlands. Even at the time of the field investigation, water vapor was coming out from volcanic product around 13 km away from the crater. The inside of the pyroclastic flow seemed to be sill at high temperature.

At the upper stream of Putih River (The south west slope of Mt.Merpai), a lot of volcanic product such as volcanic ash is deposited. Also around National Road which crosses the lower stream of Putih River, because the river width is narrow and curves a lot, many flood have occurred since November 2011. Especially, After December, a large volume of debris flow flowed down from the upper stream. The feature of this flood is including rocks which are over 2m of grain diameter.

Also, on June 25th, we implemented a field investigation with Mr.Yusuke AMANO, senior advisor to the Director General of Global Environment Department, JICA and Mr.Masashi Nishikawa, staff of Southeast Asia Division 1,Southeast Asia & Pacific Department, JICA, who visited Indonesia as pre-investigation team regarding (Yen Loan) Urgent Reconstruction Project for Mt. Merapi Eruption.

Gendol River Sabo Dam 1

Near cross point of Putih River and National Road