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CHAPTER V CONCLUSSION
5.1. RESULT From this research the author obtained much good additional knowledge. Many new things that can be observed, studied and became a valuable experience, be it in science, as well as moral messages. There are several result of this research below: a. Based on the estimation of amount of debris flow in Gendol river about 1547899.16 m3. b. Based on the estimation of the capacity volume of sediment control structure (sabo) in Gendol river about 1165838.60 m3. c. There are 382060.56 m3 sediment cannot accommodated by the sediment control structure (sabo) in Gendol river. d. In conclusion the sediment control structure in Gendol river is ineffective to mitigate the losses during the debris flow. e. There is six suggested sediment control structure that should be built to anticipate the losses during debris flow. f. After adding six sediment control stricture (sabo) capacity of sediment control structure become 1553110.18 m3. g. Furthermore, the sediment control structure along Gendol river is only accommodate 75% from the total debris flow 1547899.16 m3 or
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1165838.60 m3 only that mean there 25% or about 382060.56 m3 losses sediment flow and harmful for the downstream area. h. Sand mining is recommended in order to keep the structure in good condition so the structure can work properly i. Beside that construct another sediment control structure in Gendol river become the best solution to minimize the losses sediment. In order to balancing the sediment and the structure, six Sediment control structure should be added on the Gendol river. The detail information about those six sediment control structure (sabo) see Table 4.6 Balanced Sediment. a. The first recommendation structure is located on Glagasari which dimension is 13.00 m height and 80.00 m width that can accommodate around 108488.20 m3 of sediment from debris flow. The second recommendation structure is located on Sindumartani dimension is 8.00 m height and 70.00 m width that can accommodate around 58416.72 m3 of sediment from debris flow. b. The next recommendation structure is located on Agromulyo with dimension 6.50 m height and 65.00 m width this structure can accommodate around 44073.33 m3 of sediment from debris flow. c. The next recommendation structure is located on Kepuharjo with dimension 13.00 m height and 70.00 m width this structure can accommodate around 94927.17 m3 of sediment from debris flow. d. The next a couple’s structure is located on the downstream of GE-C0 (Tulung) separate on different elevation with the dimension about 6.0 m
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height and 65.00 m width each structure can accommodate around 40683.07 m3 of sediment from debris flow. For more information about location of proposed six sediment control structure shows on the figure below. See Figure 5.1 Suggestion of New Sediment Control Structure Location.
5.2. RECOMMENDATION Based on this research the author would like to give some recommendation for related parties. a. There are many sediment control structure distributed into several rivers from Merapi. And every instance has their own data about the sabo. This make the information is scattered and incomplete. This make the monitoring harder, because the specification data and the other record are hold by other organization. Therefore, making a centralized data base, which every instance can access, will make the data easier to analyze and complete. This will also make research in sediment control structure become easier. b.
Rehabilitate and repair the damaged building.
c. Conducted investigation to assess the damages in the building based on existing procedure. d. Forming a community to give knowledge to the society about the sediment controlling structure and its benefits.
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e. With a good awareness of the society about the benefits of the sediment controlling structure, therefore the society will also protect the structure so it can always be operated in a good condition.
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Figure 5.1 Suggestion of New Sediment Control Structure Location.
REFERENCES
Chairil, S. Setyono, E, Hidayat, R.F., 2012 Analisis Peningkatan Kapasitas Kantong Lahar Kali Regoyo Desa Regoyo
Kabupaten Lumajang.,
Jurusan Teknik Sipil Universitas Muhammadiyah Malang Dedi, S., Heru, A.S., and Surendro A.W., Fikri, A.K., Maria. U., 2015 Pengendalian Aliran Sedimen Pada DAS Kali Mujur Gunung Semeru, on Annual Report of Depatemen Pekerjaan Umum PPK Penanganan Bencana Sedimen. Kementrian Pekerjaan Umum Direktorat Jenderal Sumber Daya Air Direktorat Sungai dan Pantai Satuan Kerja Direktorat Sungai, Danau dan Waduk Kegiatan Penanganan Sedimen, 2006, Desain Sabo, ISBN 978-602-969894-7 Joesron, L., 1986, Banjir Rencana untuk Bangunan Air, Departemen Pekerjaan Umum. Mukhlisin, 1998, Pengaruh Curah Hujan Terhadap Pembentukan Aliran Debris, Tesis Magister, Progran Studi Teknik Sipil, Sekolah Pascasarjana Fakultas Teknik, Universitas Gajah Mada, Yogyakarta Nobutomo, O, Mizuno, H, and Mizuyama, T., 2010 Design Standard of Control Structures Against Debris Flow in Japan, on Erosion and Sediment Control Division, Research Center for Disaster Risk Management, National Institute for Land and Infrastructure Management, Ministry of Land, Infrastructure, Transport and Tourism, Japan
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Priyantoro, D, 1987, Teknik Pengangkutan S e d i m e n , Fakultas Teknik Jurusan Pengairan Universitas Brawijaya Malang. Departemen Permukiman dan Pengembangan Wilayah Direktorat Jenderal Pengembangan Perdesaan, 2000(a), Draft Manual Perencanaan Sabo, Proyek Pengembangan dan Rekayasa SABO. Departemen Permukiman dan Pengembangan Wilayah Direktorat Jenderal Pengembangan Perdesaan, 2000(b), Contoh Aplikasi Perencanaan SABO, Proyek Pengembangan dan Rekayasa SABO. Rahmat, A., Djoko, L., and Haryono K., 2010 Pengelolaan Sedimen Kali Gendol pasca erupsi 2006 An Journal of Sabo Technical Center 2010. Takahashi T., Nakagawa H. and Kuang S. (1987): Estimation of debris flow hydrograph on varied slope bed. Erosion and Sedimentation in the Pacific Rim, IAHS Publ. 165, pp. 167–177 Voight, 2000, Historical of Merapi Volcano, Central Java Imdonesia. 1768-1998. Journal of Volcanology and Geothermal Research.
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ATTACHMENT
76
77
Static Volume 100000 92086.1413 90000
84102.91639
80000
Volume (m3)
70000 60000 49820.87905
50000 40000 30000 24689.38086 23836.21397
30103.59922 28008.7437 18526.29621 19252.20836 17250.36923
20000 11584.07278 10000
9693.313953
17516.25
11488.88296
10334.25
12177.06489 11524.6868 9411.057692 9176.373066 4996.570236 2507.787136 1558.055491
0
Name of Sediment Control Structure
78
Dynamic Volume 140000.000 122781.522 120000.000
112137.222
Volume (m3)
100000.000
80000.000 66427.839 60000.000
40000.000
31781.619
32919.174
40138.132 37344.992
24701.728 25669.611
20000.000
15445.430
12924.419
23000.492
13779.000
23355.000
15318.511
15366.249 12235.164 2077.407
0.000
Name of Sediment Control Structure
12548.077
16236.087 6662.094 3343.716
79
Total 250,000.00 214,867.66
Volume (m3)
200,000.00
196,240.14
150,000.00 116,248.72 100,000.00
55,617.83
57,608.56
70,241.73 65,353.74
43,228.02 44,921.82
50,000.00 27,029.50
22,617.73
40,250.86 40,871.25 26,807.39
26,890.94 21,411.54
3,635.46 -
Name of Sediment Control Structure
24,113.25 28,413.15 21,959.13 11,658.66 5,851.50
80
Volume (m3)
Storage Volume of Sediment Control Structure at Gendol River 230000 220000 210000 200000 190000 180000 170000 160000 150000 140000 130000 120000 110000 100000 90000 80000 70000 60000 50000 40000 30000 20000 10000 0
Name of Sediment Control Structure Static Volume
Dynamic Volume
Total
