One indicator of national food security is rice production, generated from the crop area in irrigation area. Influencing policy is regulation and changes in strategic environment , which are both synergized in the form of irrigation system. JICA Study -FIDP , 1993, indicating ABSTRAKSalah satu indikator dari ketahanan pangan nasional adalah produksi beras yang dihasilkan dari luas areal panen seluruh daerah irigasi. Kebijakan yang mempengaruhinya adalah peraturan/perundangan dan perubahan lingkungan strategis, yang keduanya bersinergi dalam bentuk sistem irigasi. Studi JICA-FIDP 1993 mengindikasikan perkembangan luas area irigasi akan berpindah ke Pulau Sumatera, Kalimantan, dan MalukuPapua, namun rekaman data produksi 20 tahun terakhir pada wilayah tersebut masih rendah. Kajian ini bertujuan untuk mencari solusi atas harapan peningkatan produksi beras dengan menganalisis daerah mana saja yang mempunyai potensi peningkatan atau percepatan produksi. Pendekatan data Mining Konsep Kmeans menjadi metode dalam menganalisis pengelompokan propinsi pada produksi padi Nasional, analisis tersebut berdasarkan rekaman data produksi padi dari tahun 1993 sampai dengan 2012 atau selama 20 tahun dari 33 Propinsi di seluruh Indonesia, dengan objek pengamatan pada rata-rata produksi terhadap peningkatan produksi (slope/kemiringan) dan perkiraan (forecast) produksi tahun 2013. Berdasarkan simulasi hasil optimasi dengan K-Means didapatkan urutan pengembangan produksi padi yang terdiri dari enam kelompok. Produksi tertinggi padi nasional masih di dominasi oleh Pulau Jawa dan Bali (kelompok 1), artinya pengembangan pada wilayah ini memanfaatkan potensi seoptimal mungkin dan diperlukan upaya lebih untuk mempertahankan luas area dengan mencegah alih fungsi lahan, namun karena keterbatasan lahan (potensi pengembangan hanya 62000 Ha), maka pengembangan area irigasi lebih rasional diprioritaskan pada kelompok 2 yaitu Wilayah Sulawesi, NTB, dan Sumatera Barat. Simulasi hasil optimasi tersebut sudah mengakomodir riwayat produksi pada dimensi masa lampau, saat ini dan perkiraan produksi mendatang berdasarkan peningkatan yang terjadi. Kata Kunci: produksi padi nasional, lahan irigasi, perkiraan produksi, K-Means, data mining

Floods that occur in the Upper Citarum River Basin are generally caused by flood discharge that exceeds the capacity of the Citarum River. Dayeuhkolot is one of the areas that is often flooded in the Upper Citarum River Basin. The Citarum River Authority has made efforts to handle floods in Upper Citarum by constructing the Nanjung Tunnel. When floods occur, Nanjung Tunnel will function to divide the water partially into the tunnel and through the Curug Jompong. SOBEK Model was utilized to find out the effect of the Nanjung Tunnel against flood inundation in Dayeuhkolot. This flood modelling also accommodates other efforts that have been made by BBWS Citarum such as the Cieunteung Pond and Cisangkuy Floodway. A 20-year return period was used for modelling. From the results of the modelling, it was found that difference in flood inundation area with and without the Nanjung Tunnel was 12.5 Ha or 3.5 %, with the duration of the overall inundation being reduced by 4.9 hours. Nanjung Tunnel does not have a great influence on the area of inundation, but it has an effect on reducing the duration of floods that occur in Dayeuhkolot.

The Cisangkuy river basin located in the south of Bandung Metropolitan has been suffering from serious water scarcity, river pollution, and flood damage due to rapid increase in population and industrialization in the Bandung Metropolitan and surrounding upstream area. In order to solve these complicated water management issues, it needs to implement innovative measures for integrated basin water management. As part of these efforts, a cooperative research project between Indonesia and Korea has initiated to develop smart water management system in the Cisangkuy river basin. This paper deals with the spatial-temporal water balance analysis and shows the results of effect analysis with regard to structural measures and nonstructural measures. As the result of analysis, the power generation capacity and water supply safety are improved by 1.4~2.7% and 0.8~1.2%, and water shortage is decreased from 223 days to 190 days in case of the implementation of non-structural measures. It shows that new operation rule will contribute not only for securing additional water through the implementation of non-structural measures but also improvement of water facilities management efficiency. In case of applying the planned intake (3.3 m3/s) under current water supply system, water supply safety was decreased by 8.3% (92.3→84.0) at the Cikalong Intake and decreased by 12.5% (75.3→62.8) at the Pataruman gauge station in the Cisangkuy river (Q95% condition) respectively in comparison with present intake condition. It indicates that additional water supply is necessary to meet the increased water demand. Alos according to the evaluation on the effect of new Cikalong dam, consistent water supply (0.35 m 3 /s) is possible at Cikalong intake station. However, water supply safety at Pataruman for river maintenance flow and Ciherang irrigation water were decreased by 2.4~4%.

Abstract. One of the alternative flood structural mitigation planned for Rongkong River is the construction of embankments and river normalization. However, river normalization has a weakness where the widening of the cross section of the river can cause an increase in sedimentation. The purpose of this study is to examine the effectiveness of the planned flood control in reducing flood runoff using the flood overflow hydraulic model. Rongkong basin was divided into 14 subbasin to create a distributive model. Design rainfall was analyzed using frequency distribution analysis with GEV method at various return period. Flood discharge was analyzed using HEC-HMS software with the SCS and Snyder methods on the 20-year return period. Hydraulic modelling was analyzed using HEC-RAS 1D with unsteady flow condition under existing and design cross section. Based on the results of flood modeling with a flood discharge Q20 of 1,046.78 m3/s resulted in a flood reduction of 100% and an increase in the average flow velocity of 18% from 1.82 m/s to 2.14 m/s. The use of Q20 as a design flood discharge in the normalization plan and construction of the Rongkong River embankment is considered too large because it causes construction costs to be very expensive. It is recommended to use Q10 in accordance with the regulation of the Ministry of Public Works and Housing, which is stated that the flood design for embankments of the river near the regency/city capital area must be able to pass the flood discharge of Q10 – Q20. It is needed to conduct a design review of the plan of normalization and construction of the embankment. Keywords: Flood control, river morphology, hydraulic modelling, HEC-HMS, HEC-RAS Abstrak Salah satu alternatif mitigasi struktural banjir yang direncanakan untuk Sungai Rongkong adalah pembangunan tanggul dan normalisasi sungai. Namun normalisasi sungai memiliki kelemahan dimana pelebaran penampang sungai dapat menyebabkan peningkatan sedimentasi. Tujuan dari penelitian ini adalah untuk menguji efektivitas pengendalian banjir yang direncanakan dalam mengurangi limpasan banjir dengan menggunakan model hidraulik limpasan banjir. DAS Rongkong dibagi menjadi 14 Sub DAS untuk membuat model secara distributif. Curah hujan rencana dianalisis menggunakan analisis distribusi frekuensi dengan metode GEV pada berbagai periode ulang. Debit banjir dianalisis menggunakan software HEC-HMS dengan metode SCS dan Snyder pada kala ulang 20 tahun. Pemodelan hidraulik dianalisis menggunakan HEC-RAS 1D dengan kondisi aliran tidak tunak pada penampang eksisting dan rencana. Berdasarkan hasil pemodelan banjir dengan debit banjir Q20 sebesar 1.046,78 m3/s menghasilkan reduksi banjir sebesar 100% dan peningkatan kecepatan aliran rata-rata sebesar 18% dari 1,82 m/s menjadi 2,14 m/s. Penggunaan Q20 sebagai debit banjir rencana dalam rencana normalisasi dan pembangunan tanggul Sungai Rongkong dinilai terlalu besar karena menyebabkan biaya konstruksi menjadi sangat mahal. Direkomendasikan untuk menggunakan Q10 sesuai dengan peraturan Kementerian Pekerjaan Umum dan Perumahan Rakyat yang menyatakan bahwa desain banjir untuk tanggul sungai di dekat wilayah ibukota kabupaten/kota harus dapat melewati debit banjir Q10 – Q20. Selain itu juga perlu dilakukan kajian desain terhadap rencana normalisasi dan konstruksi tanggul. Keywords: Pengendalian banjir, morfologi sungai, pemodelan hidraulik, HEC-HMS, HEC-RAS