Judul: Evaluation Of Dam Safety Based On Risk Indexing Tools On Jatiluhur Dam, West Jawa
Abstrak: Indonesia has high water surface potential. It is proved by a lot of big rivers in Indonesia. In order to utilize its water potential optimally, it need a water conservation structure. Generally, the water conservation structure is a dam because of its many functions. There are some big dams in Indonesia, one of them was Ir. Juanda dam or Jatiluhur Dam. The main purpose of the dam is to provide water irrigation . Nowadays dam has many functions, such as power supply to produce electricity, reservoir, recreation and flood control. To fullfill those functions dam must be maintain regularly. The objectives of the research were to identify the factors which affect dam safety and to evaluate dam safety by risk indexing tools. Risk indexing tools is a method for making priority scales of maintenance, improvement and evaluation of dam that has limited instrumentation, based on its actual condition and performance. There were six main steps of this research. The steps were to analyse (1) vulnerability factors, (2) intrinsic factors, (3) external factors, (4) adequacy factors, (5) the stage of initial importance and (6) the value of total risk index. All of the steps were done in a sequence from step one to the last steps. The result showed that Jatiluhur dam was still in safe condition and can operate as its planed. This was proven based on several factors values such as Idam=750, IRtot=127,22, Nsafe=83,04. The conclusion of this study was Jatiluhur dam’s safety was in satisfied category with Nsafe value more than 75.
Keyword: dam load, dam safety, Jatiluhur dam, risk indexing tools

Judul: Stability Slope Analysis of Main Dam Planning
Abstrak: Main dam merupakan salah satu bangunan hidrolika pada suatu waduk/bendungan yang berfungsi sangat penting dalam menahan tampungan air, sehingga perlu diperhitungkan kekuatan dan keamanannya secara cermat. Penelitian ini bertujuan untuk melakukan kaji ulang stabilitas lereng pada perencanaan main dam berdasarkan muka air normal (MAN) dan muka air banjir (MAB). Hasil analisis debit inflow menunjukkan bahwa pada kondisi volume tampungan normal sebesar 10.40 juta m3/detik, elevasi muka air normal bendungan pada 94.27 mdpl. Pada elevasi tersebut, kedalaman bendungan adalah 29.27 m dari dasar bendungan. Hasil analisis debit banjir terpilih menggunakan metode HSS Nakayasu dengan distribusi hujan durasi 6 jam sebesar 189.82 m3/detik, sehingga diperoleh elevasi muka air banjir bendungan sebesar 95.72 mdpl. Pada elevasi tersebut, kedalaman bendungan setinggi 30.37 m dari dasar bendungan. Berdasarkan parameter muka air, beban akibat angin, kenaikan muka air akibat abnormal operasional pintu bangunan, dan tambahan tinggi jagaan berdasarkan tipe bendung, tinggi jagaan main dam yang diperoleh sebesar 2.97 m. Stabilitas lereng main dam aman dengan analisis faktor keamanan (FK) menggunakan software rocscience untuk kondisi MAN diperoleh sebesar 1.37 dan MAB diperoleh sebesar 1.25. Kondisi tersebut memenuhi syarat faktor keamanan minimum stabilitas dengan tambahan beban gempa (FK ≥ 1.2)., Main dam is one of the hydraulic structures in a dam which has a very important function in holding water reservoirs, so its strength and safety need to be carefully calculated. This study aims to review slope stability in main dam planning based on normal water level (MAN) and flood water level (MAB). Results of the discharge inflow analysis showed that normal conditions were 10.40 million m3/ sec, normal water level at 94.27 mdpl. At this elevation, the depth of the dam was 29.27 m from the bottom of the dam. The result of selected flood discharge analysis using the Nakayasu HSS method with a rainfall distribution of 6 hours duration was 189.82 m3/second, so that the flood water level of the dam was obtained at 95.72 mdpl. At this elevation, the depth of the dam was 30.37 m from the bottom of the dam. Based on water level parameters, wind loads, water level rise due to abnormal building door operations, and additional guard height based on the type of dam, guard height main dam obtained was 2.97 m. Slope stability of the main dam was considered good by factor of safety analysis (FK) using rocscience software for MAN conditions obtained by 1.37 and MAB obtained by 1.25. This condition met the requirements for the minimum safety factor of stability with additional earthquake loads (FK ≥ 1.2).
Keyword: discharge, flood, stability, water level

Judul: Penggulung daun Sylepta sp. (Lepidoptera: Crambidae) pada Boehmeria minuticymosa (Urticaceae):
Abstrak: Sylepta sp. (Lepidoptera: Crambidae) merupakan kelompok hama yang bersifat polifag. Larva hama ini menyebabkan daun menggulung. Salah satu tanaman inang hama ini adalah gulma Boehmeria minuticymosa N. Acharya & Yonek (Urticaceae). Larva sering diparasit oleh beberapa parasitoid, sehingga bisa bermanfaat sebagai inang alternatif parasitoid dalam pengendalian biologi. Tujuan dari penelitian ini yaitu mengamati beberapa aspek biologi hama ini dan parasitoidnya pada B. minuticymosa. Penelitian dilaksanakan di Laboratorium Biosistematika Serangga, Departemen Proteksi Tanaman, Fakultas Pertanian, Institut Pertanian Bogor, dari bulan Februari hingga Agustus 2018. Larva Sylepta sp. diperoleh dari lapangan dan dipelihara di laboratorium. Aspek biologi yang diamati meliputi jumlah instar larva, stadium larva dan pupa, lama hidup imago, dan parasitoidnya. Hasil penelitian menunjukkan bahwa Sylepta sp. memiliki empat instar. Rata-rata stadium larva dan pupa adalah 19.59 dan 8.33 hari. Larva menggulung daun dan memakannya dari bagian dalam daun. Pupa berwana cokelat gelap. Lama hidup imago jantan dan betina adalah 4.18 dan 6.09 hari. Parasitoid dari hama ini termasuk Ordo Hymenoptera, Famili Braconidae dan Bethylidae (parasitoid larva) dan Chalcididae (parasitoid pupa).
Keyword: gulma, hama, Hymenoptera, serangga, Urticaceae