THE ANALYSIS OF SABO DAM PERFORMANCE AS A SEDIMENT CONTROL STRUCTURE IN PUTIH RIVER, MT. MERAPI
ABSTRACT: Mt. Merapi’s
eruption which occurred on 26 October 2010 had disadvantageous impact for human
life that live surrounds it. The primary disaster was pyroclastic cloud that
destroyed villages surround it. In addition, the secondary disaster
continuously became a threat for human life around the rivers that destroyed at
Mount Merapi. One of the secondary disasters is Putih River’s volcanic material
overflowing into Yogyakarta-Magelang Highway. The series of Sabo dam which had
been built along the river could not handle that phenomenon. Sabo dam was built
and expected to accommodate volcanic material or at least to resist the
velocity of volcanic material (sediment controlling), so the damage caused by
the flow became relatively small. However, this function could not work at that
phenomenon. In order to know the function of sediment control of Sabo dam in
Putih River, it is necessary to study the performance of Sabo dam. This
research used Kanako software ver. 2.04 and reviewed Sabo dam PU-D1 Mranggen
and PU-C8 Ngaglik. There were four simulated scenarios in this research: a
scenario without Sabo dam; with Sabo dam PU-D1 Mranggen; with Sabo dam PU-C8
Ngaglik, and the last with two of Sabo dams. The simulation was based on 23
January 2011 event and simulated for 18.000 s. From this research, it can be
concluded that Sabo dam PU-D1 Mranggen can reduce the total volume passing
through about 43,998.6 m3 or 1.53 % for 5 hours, and reduce the sediment volume
that passing through about 28,482 m3 or 52.59 % for 5 hours. Sabo dam PU-C8
Ngaglik can reduce the total volume that passing through about 255.6 m3 or 0.01
% for 5 hours, and reduce the sediment volume that passing through about 124.8
m3 or 0.33 % for 5 hours, and Sabo dam PU-D1 Mranggen and PU-C8 Ngaglik in
series can reduce the total volume that passing through about 2,340.6 m3 or
0.08 % for 5 hours, and reduce the sediment volume that passing through about
157.8 m3 or 0.41 % for 5 hours
Author: Andre Wisoyo
Journal Code: jptsipilgg120040
