#TITLE_ALTERNATIVE#

• Main Author: Murod (NIM : 950 00 021), Khoirul
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/8408
• Institution: Institut Teknologi Bandung

Abstract: <br /> <br /> <br /> <br /> <br /> Boyong river is one of rivers in which the upstream refers ti Merapi volcano. The Boyong river flows down and split Yogyakarta municipality. So, it is understood that Yogyakarta is sensitive to volcano eruption disaster. The eruption effects may be direct such as hot cloud and indirect effect such as flow of lahar or debris. <br /> <br /> <br /> <br /> <br /> To protect Yogyakarta municipality from the above volcano eruption disasater, it has been developed sabo technology which constructs check dam in Boyong river. There are 7 exiyfmg check dams up to present. There is Boyong Dam number 7 (BO D7 ) as open check dam type and Boyong Dam number 6 (BO D6) is the next as closed check dam type. <br /> <br /> <br /> <br /> <br /> The function of check dam is to control sediment, in which temporarily catches the sediment when flood comes and releases the sediment when small discharge takes place. This condition makes possibility to catch the next sediment lahar or debris carried by the next flood. <br /> <br /> <br /> <br /> <br /> When lahar or debris flood occur in 1995. BO D6 was able to control sediment 28.65%. The time needed to reopen new space was 3 days. Whereas the occurance in 2000, sediment can be controlled was equal to 28.98%. The time needed to reopen new space was 31 days. <br /> <br /> <br /> <br /> <br /> On other hand, in January 18, 1998 when lahar or debris flood taken place BO D7 was able to control sediment was equal 9.1%, and needed 17 days of flushing. The BO D7 was able to control sediment equal to 12.35% on February 16, 1998. The time to flush sediment was 3 days. On 24 February the amount of sediment to be controlled reached 9.42%, and needed 45 days of flushing.