Flood generally caused by the high speed of urban growth that is not balanced by efforts to avoid it. The decrease of vegetation closing and the disappearing of the natural reservoir can cause the lack of field ability to restrain rainfall and disturb surface stream flow that influences the balance of hydrology along the river basin. Hydrology models tended to be spatially distributed. By computer support with higher memory capability and faster speed, the increase of development and usage of spatially distributed models substitute lump parametric models or aggregate to spatially simple. Furthermore, there are many efforts of integration forms, either database or hydrology models with Geographic Information System (GIS). The approach of the integration of spatially distributed hydrology model and GIS is used to simulate the hydrology process interactively with the basis of spatiotemporal, with a variety of land use, rainfall, and detention reservoir volume changes (embuing/ small dam). The DEM which emerges land surface morphology information is used to represent hydrology process of surface runoff. Topography structure extraction algorithm will be the slope and the current direction is an important factor in describing drainage network. The elevation numbers and its descendants are depicted in grid cells in 50 m x 50 m measurement. The result shows such as in flood hydrograph which is varied base on land use, design rainfall and detention reservoir (embung/ small dam).

Dari optimasi operasi waduk dengan program dinamik deterministik menghasilkan pola operasi untuk waduk Sukawana. Pada tahun basah, normal dan kering, storage bulan Januari dan Desember berada pada elevasi maksimum 1475m. Pada bulan Mei sampai September terjadi penurunan elevasi air di waduk. Taraf muka air normal dijadikan pedoman dalam menjalankan operasi waduk. Taraf muka air normal yang ditentukan sebagai permulaan adalah pada bulan Mei, dimana tinggi air waduk diusahakan mencapai elevasi maksimum Untuk mencegah bahaya banjir, muka air waduk antara bulan Oktober sampai dengan bulan April diusahakan di bawah elevasi maksimum Kata-kata Kunci: simulasi neraca air, optimasi program linier, optimasi dinamik deterministik,

AbstrakIndonesia mempunyai dua musim dalam satu tahun yaitu musim hujan dan musim kemarau, Agar persediaan air dapat dimanfaatkan secara optimal baik di musim penghujan maupun di musim kemarau, dilakukan sistem pengoperasian waduk, Waduk dapat juga dimanfaatkan untuk pengairan, pembangkit tenaga listrik, pariwisata, pengendali sungai dan banjir, Dalam melestarikan waduk, masalah erosi dan sedimentasi yang akan memenuhinya, dikhawatirkan tidak akan mencapai umur waduk yang direncanakan.Penelitian dilakukan di Waduk Cirata yang berada pada dalam Wilayah Sungai Citarum, Provinsi Jawa Barat yang meliputi sebagian dari tiga wilayah kabupaten yaitu Kabupaten Bandung, Purwakarta dan Cianjur. Metode pengumpulan data meliputi data Primer dan data sekunder yang dikumpulkan dari PT Pembangkitan Jawa Bali Badan Pengelola Waduk Cirata Cirata, Hasil Kesimpulan adalah dengan masuknya sedimentasi ke dalam waduk akan mengakibatkan pengendapan dan pendangkalan yang akan mempengaruhi kapasitas tampung waduk juga semakin lama waduk beroperasi, maka semakin banyak sedimen yang mengendap didalam waduk, perbandingan antara volume sedimen yang mengendap setelah 10 tahun dan setelah 200 tahun adalah 10215287,18 m 3 dan 193953499,6 m 3 , setelah menganalisis volume sedimen yang mengendap setelah T-tahun pada waduk yang beroperasi maka akan dipikirkan rencana umur waduk selanjutnya.Kata-kata Kunci: Volume waduk, Waduk, Erosi, Sedimentasi, Umur waduk. AbstractIndonesia has two seasons of the year: the rainy season and the dry season, So that the water supply can be optimally used both in the rainy season and dry season, made the operating system of reservoirs. Reservoirs can also be used for irrigation, power generation, tourism, controllers rivers and floods, in preserving the reservoir, the problem of erosion and sedimentation will comply, it is feared will not reach the age of the planned reservoir. The study was conducted in Cirata located on the CRB, West Java Province that covers most of the three districts namely Regency Bandung, Purwakarta and Cianjur. Methods of data collection includes data Primary and secondary data collected from PT Generation Java Bali Cirata Cirata Basin Management Board, Results The conclusion is by the entry of sediment into the reservoir will result in sedimentation and silting that would affect the capacities of reservoirs also the longer the dam operates, the more sediment that settles in the reservoir, the ratio between the volume of sediment that settles after 10 years and after 200 years was 10215287,18 m 3 and 193953499,6 m 3 , after analyzing the volume of sediment that settles after T years at the reservoir operating plan will be considered next dam age.

Sedimentation is such a crucial issue to be noted once the accumulated sediment begins to fill the reservoir dead storage, this will then influence the long-term reservoir operation. The sediment accumulated requires a serious attention for it may influence the storage capacity and other reservoir management of activities. The continuous inflow of sediment to the reservoir will decrease the capacity of reservoir storage, the reservoir value in use, and the useful age of reservoir. Because of that, the rate of the sediment needs to be delayed as possible. In this research, the delay of the sediment rate is considered based on the rate of flow of landslide of the reservoir slope. The rate of flow of the sliding slope can be minimized by way of each reservoir autonomous efforts. This effort can be performed through; the regulation of fluctuating rate of reservoir surface current that does not cause suddenly drawdown and upraising as well. The research model is compiled using the searching technique of Non Linear Programming (NLP). The rate of bank erosion for the reservoir variates from 0.0009 to 0.0048 MCM/year, which is no sigrificant value to threaten the life time of reservoir. Mean while the rate of watershed sediment has a significant value, i.e: 3,02 MCM/year for Saguling that causes to fullfill the storage capacity in 40 next years (from years 2008).

Indonesia today face a new paradigm in water management where aim to apply integrated water resources management has become unavoidable task in purpose of achieving greater level of effectiveness and efficiency. On of most interesting case study is the case of Citarum river, one of the most potential river for water supply in West Java, Indonesia. Alongside the river, Saguling, Cirata and Djuanda Reservoirs had been constructed in series/cascade. Saguling and Cirata reservoirs are particularly operated for hydroelectric power and Djuanda is multipurpose reservoir mainly operated for irrigation and contribute domestic water supply for Jakarta (capital city of Indonesia). Basically all reservoirs are relying on same resources, therefore this condition has considered addressing management and operational problem. Therefore, an approach toward new management and operation system are urgently required in order to achieve the effective and efficient output and to avoid conflicts of water used. This study aims to obtain energy production from Citarum Cascade Reservoir System using Genetic Algorithms optimization with the objective function to maximize firm-energy. Firm-energy is the minimum energy requirements must be available in a certain time period. Then, the result obtained by using the energy produced by GA is compared to the conventional searching technique of Non-Linier Programming (NLP). The GA derived operating curves reveal the higher energy and firm-energy than NLP model.