1,720,975 research outputs found
ANALISA EROSI DAN USAHA KONSERVASI PADA SUB DAS KONTO HULU BERBASIS SISTEM INFORMASI GEOGRAFIS
Get PDFSub DAS Konto Hulu mempunyai sungai utama yaitu Sungai Konto yang merupakanDaerah Aliran Sungai dari Waduk Selorejo yang merupakan salah satu waduk yang berada diwilayah kabupaten Malang tepatnya di kecamatan Ngantang yang berfungsi sebagai penyedia airuntuk irigasi, perikanan, PLTA dan juga sebagai pengendali banjir. Waduk ini mendapatkan suplaiair dari tiga sungai, salah satu diantaranya dan merupakan yang terbesar adalah sungai Konto.Kondisi DAS Konto bagian hulu yang didominasi oleh bahan-bahan vulkan berdebu dan berpasirdengan jenis tanah andosol ditengarai sangat rawan terhadap erosi terutama pada lahan yangmemiliki kemiringan relatif curam sehingga menimbulkan terjadinya sedimentasi di wadukSelorejo.Untuk metode perhitungan laju erosi digunakan metode USLE dan MUSLE. Untukpemilihan metode yang akan digunakan selanjutnya di lakukan proses kalibrasi data sedimenhasil simulasi dan data sedimen hasil pengukuran di lapangan. Selanjutnya dilakukan analisatingkat bahaya erosi dan tingkat kekritisan lahan, kemampuan penggunaan lahan dan arahanfungsi kawasan. Dari kemampuan penggunaan lahan dan arahan fungsi kawasan maka dapatdirekomendasikan penggunaan lahan yang baru.Berdasarkan analisa laju erosi, laju sedimentasi dan kalibrasi perhitungan dengansedimentasi hasil pengukuran di lapangan didapatkan hasil bahwa laju sedimentasi di lapanganadalah sebesar 329.800,068 ton/thn, laju erosi dengan metode USLE adalah sebesar 34.117,983ton/ha/thn dengan laju sedimentasi sebesar 150.956,179 ton/thn atau sama dengan kehilangantanah sebesar 2,78 mm/thn dan nilai volume error 54,23 % sedangkan dengan metode MUSLEadalah sebesar 17.749,837 ton/ha/thn dengan laju sedimentasi sebesar 343.954,487 ton/thn atausama dengan kehilangan tanah sebesar 1,5 mm/thn dan nilai volume error 4,29 % sehinggadiputuskan bahwa analisa selanjutnya menggunakan metode MUSLE. Selain itu juga didapatkanhasil bahwa lahan dengan tingkat bahaya erosi sangat ringan seluas 5502.552 ha, ringan6673.096 ha, sedang 1563.084 ha, berat 558.148 ha dan sangat berat 27.310 ha. Berdasarkanhasil analisa kemampuan penggunaan lahan diketahui bahwa lahan masuk dalam kelas IIIeseluas 65.009 ha, IIIg 162.541 ha, IVe 321.082 ha, IVg 996.738 ha, Vg 9778.819 ha, VIe1036.921 ha, VIs 187.187 ha, VIIe 538.344 ha dan VIIg 1237.549 ha. Berdasarkan arahan fungsikawasan diketahui bahwa 6193.028 ha lahan sebaiknya difungsikan sebagai kawasan lindung,7903.612 ha dapat difungsikan sebagai kawasan penyangga dan 227,550 dapat difungsikansebagai kawasan budidaya baik itu budidaya tanaman tahunan atau semusim. Berdasarkan halhaltersebut maka dapat direkomendasikan penggunaan lahan baru. Berdasarkan simulasiterhadap penggunaan lahan baru dan usaha konservasi diperoleh hasil bahwa terjadi penurunanlaju erosi dari semula 17.749,837 ton/ha/thn menjadi 7.969,858 ton/ha/thn dan penurunan lajusedimentasi dari semula 343.954,488 ton/thn menjadi 134.623,457 ton/thn atau sama dengankehilangan tanah sebesar 0,59 mm/thn
Kajian Kemampuan Maksimum Danau Sentani Dalam Mereduksi Banjir Di DAS Sentani
Get PDFLake Sentani which located at Jayapura Regency is known as one of largest and most beautiful lakes in the province of Papua . About 14 rivers is flowing into Lake Sentani, thus one of its main functions is as a flood catchment. Based on the research conducted by Balai Wilayah Sungai Papua in 2012, it can be measured that the capacity of Lake Sentani is equal to 4.821.49 million m .
The aim of this research is to analyze the flood discharge into Lake Sentani caused by land use changes from the use for every 3 years (2007, 2010 and 2012). The simulation of the flood discharge at the outlet and flood routing was made using the Muskingum method.
From the analysis, it is shown that the discharge at outlet (Qout) was less than the discharge from inflow (Qin) as a result of simulation. The flood reduction (which was formed as a percentage) can be calculated as a ratio between the differences of (Qin - Qout) and inflow discharge (Qin). By this formula, it can be calculated that the average of flood reductions were 86,18% (2007), 86,22% (2010) and 86,23% (2012), by using simulation from eight different Return Period Discharge (Q2 to Q1000). Thus it can be concluded that Lake Sentani still has an adequate capacity to reduce flooding from the upstream zone of Sentani Catchment Area.
From the results, it is found that the flood discharge is affected by the changes of catchment area and land use. Under these changes, the runoff coefficient will be changed as well.
Keywords: Maximum Capacity, Flood Discharge, Flood Reductio
Optimasi Pola Operasi Waduk Sutami Menggunakan Model Pemrograman Linier Kabur (Fuzzy Linear Programming)
Get PDFSutami Reservoir is located in Karangkates Village, Sumber Pucung District, Malang Regency. Its primary benefits are for flood control, irrigation, power generation of 3 x 35 MW, and to supply a minimum discharge of 56 m 3 /sec for downstream regions. Early on, it was planned that the minimum discharge for the hydropower turbine would be 25 m /sec and the maximum discharge would be 51.39 m 3 /sec. In its 40 years of age, the turbine has only been capable of handling a maximum discharge of 46.09 m 3 /sec. Electricity production can be maintained by optimizing the outflow that enters the turbine. A model was designed using a fuzzy linear programming model, which is combined with a simulation model for reservoir operating rule performance evaluation. In this study, an optimization of 11 years was obtained, in the form of optimal energy production of 5606.66 GWh, a new rule curve for the regulation of water surface levels, and a simulated result of 100% reliability for the model and existing implementation.
Keywords : Fuzzy linear programming, optimization, simulation, reservoir operation rule, Sutami reservoir
Pengembangan Jaringan Distribusi Air Bersih PDAM Perumnas Kota Baru Driyorejo Gresik
Get PDFUpaya pemenuhan kebutuhan air bersih pada suatu daerah hendaknya memperhatikan ketersediaan sumber air yang ada. Begitu juga di Perumnas Kota Baru Driyorejo. Sesuai target nasional PDAM Kabupaten Gresik yaitu sebesar 80% masyarakatnya terpenuhi kebutuhan air bersihnya sehingga diperlukan peningkatan pelayanan dengan memanfaatkan jaringan distribusi yang telah ada dan merencanakan pengembangan jaringan baru. Pemenuhan kebutuhan air bersih di Perumnas Kota Baru Driyorejo memanfaatkan sumber air yang berasal dari IPA Krikilan dan IPA Legundi. Adapun kebutuhan air bersih di daerah studi termasuk dalam kebutuhan domestik dan non domestik dengan mempertimbangkan faktor kehilangan air. Kajian ini bertujuan untuk mengetahui kebutuhan dan ketersediaan air sampai dengan tahun 2020 serta mengetahui kondisi hidrolis dari sistem jaringan pipa yang ada. Simulasi jaringan pipa dilakukan dengan bantuan program WaterCAD v 4.5. Perhitungan dilakukan dengan simulasi kondisi tidak permanen dimana kebutuhan air berubah sesuai dengan kebutuhan tiap jamnya. Berdasarkan hasil akhir simulasi, dapat dilihat bahwa sistem jaringan pipa dapat berjalan. Hal ini berdasarkan kondisi tekanan yang sudah sesuai dengan syarat perencanaan dan kondisi reservoar yang mampu untuk memenuhi kebutuhan air bersih di daerah studi.
Kata Kunci: kebutuhan air bersih, kehilangan air, jaringan pipa, kondisi tidak permanen, reservoar
Hydrological Analysis of TRMM (Tropical Rainfall Measuring Mission) Data in Lesti Sub Watershed
Get PDFAlternative solution for availability of inadequate rain data as input to hydrological data is with the assist of TRMM (Tropical Rainfall Measurement Mission) satellite rainfall data which using remote sensing technology (satellite). The purpose of this study is to look for correlations and data corrections and validate TRMM satellite data with rainfall data at the rain station and discharge observation data. Lesti sub-watershed is used as a case study with consideration of the data availability that is considered sufficient. The validation results of corrected TRMM rain data produce Nash-Sutcliffe Efficiency (NSE), Root Mean Squared Error (RMSE), Correlation Coefficient (R), and Relative Error/Kesalahan Relatif (KR). Then, conducted an analysis of the flow discharge estimation using TRMM rainfall data and validated with Tawangrejeni AWLR (Automatic Water Level Record) data. The results of flow discharge validation using the FJ Mock Method produce an NSE value of 0,507, RMSE 19,383, Correlation Coefficient (R) 0,713, and Relative Error of 0,001. Overall analysis shows TRMM data can be used as an alternative of the rain data that is used to estimate flow discharge, but the result of flow discharge analysis is still better using rainfall data from the rain station pos
ANALISA OPTIMASI INTENSITAS TANAM DAN SENSITIVITAS DAERAH IRIGASI RAMBUT KABUPATEN TEGAL
No full textAbstrak: Daerah Irigasi Rambut terletak di Kabupaten Tegal, Provinsi Jawa Tengah dengan luas areal 7.634 ha untuk mengaliri Kecamatan Warureja dengan luas areal 3.740 ha dan Kecamatan Suradadi dengan luas areal 3.894 ha. Permasalahan yang ada pada daerah irigasi ini adalah terbatasnya debit yang tersedia di Bendung Cipero terutama pada musim tanam III. Dalam penelitian ini ditekankan bagaimana mengoptimalkan debit irigasi dengan melakukan modifikasi pola tata tanam (5 alternatif modifikasi pola tata tanam) dan penentuan luas tanam untuk memperoleh intensitas tanam paling maksimum dengan keuntungan paling besar sehingga bisa didapatkan pola tanam yang terbaik.
Hasil dari optimasi didapatkan intensitas tanam paling maksimum sebesar 216,24% dengan keuntungan sebesar  Rp 219.754.752.741,74 yang merupakan hasil optimasi alternatif II.  Untuk hasil analisa sensitivitas pada saat MT I harga padi sensitif diantara harga 0 - Rp 15.310.000,00; MT II harga padi sensitif diantara harga 0 - Rp 13.862.500,00 dan saat MT III harga palawija sensitif diantara harga 0 – Rp 8.665.000,00. Sementara itu harga tebu saat MT I, MT II, MT III sensitif diantara harga 0 - Rp 26.585.000,00. Luas lahan MT I sensitif diantara 1.239,71 ha - 7634 ha, luas lahan MT II sensitif diantara 4.562,60 ha - 7634 ha dan MT III sensitif diantara 6.500,36 ha - 7634 ha. Kebutuhan air MT I sensitif diantara 0 – 29.539.900,80 m3, saat MT II sensitif diantara 1.388.893,09 m3 - 2.298.703,41 m3 dan MT III sensitif diantara 1.868.910,43 m3 - 2.138.486,18 m3.
Kata Kunci: Irigasi, Optimasi, Sensitivitas, Intensitas Tanam
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Abstract: Rambut Irrigation district located in Tegal Regency, Central Java Province, with total area of 7.634 ha is used to irrigate Warureja sub-district with 3.740 ha and Suradadu sub-district with 3.894 ha. Main problem in this irrigation district is limited discharge that are available in Cipero Weir especially in 3rd crop season. This study emphasize on optimization of available irrigation discharge by conducting crop pattern modification (5 alternatives) and crop-growing range setting in order to obtain the most effective crop pattern based on the highest cropping intensity which lead to highest yield and economic advantage.
Optimization result shows that alternative III of crop pattern modification present highest cropping intensity about 216,24 and provide benefit about Rp 219.754.752.741,74. Value Sensitivity Analysis shows that rice value were sensitive in range of 0 - Rp 15.310.000,00 on 1st crop season (MT I); 0 - Rp 13.862.500,00 on 2nd crop season (MT II), while palawija value is sensitive in range of 0 - Rp 8.665.000,00 on 3rd crop season (MT III). While sugarcane value sensitive in range of 0 - Rp 26.585.000,00 on all crop season (MT I, MT II & MT III). For the Area-Range Sensitivity, 1st crop season (MT1) is sensitive in range of 1.239,71 ha  – 7634 ha, 2nd crop season(MTII) is sensitive in range of 4.562,60 ha - 7634 ha and 3rd crop season (MT III) are all sensitive in range of 6.500,36 ha - 7634 ha. Water requirement sensitivity analysis shows that 1st crop season (MT I) sensitive for water requirement in range of 0 – 29.539.900,80  m3. 2nd crop season (MT II) in range of 1.388.893,09 m3 - 2.298.703,41 m3 and 3rd crop season (MT III) in range of 1.868.910,43 m3 - 2.138.486,18 m3.
Keywords : Irrigation, Optimization, Sensitivity, Crop Intensit
Analisis Perubahan Tataguna Lahan Terhadap Usia Bendungan Tilong Di Das Tilong Kabupaten Kupang Propinsi Ntt
Get PDFThe forest degradation rate reached 2,83 million ha every year. From the total forest area of 120,5 million ha, about 59 million ha were critical areas. Besides, the critical Watersheds ini Indonesia increased. The watershed conservation efforts had brought motivation to develop the erosion estimation technologies that could assist in solving the erosion rate estimation problems spatially. The study was carried out at Tilong Watershed, Kupang Regency of NTT Province. The results showed that the value of erosion rate in Tilong Watershed area with existing (year 2010) land utilization condition was 25.428,155 ton/year where the Tilong Watershed total wide was 4.948,75 Ha. Whereas the sediment potential was 7.319,524 ton/year. The Erosion Danger Level was 74,62 %. One of the assumptions why the land erosion rate was very high was because of the misuse of the land in that area. To control the erosion rate, focussed to the recommendation of land utilization direction that referred to The Soil Conservation and Rehabilitation Program (ARLKT) and building of 8 check dam. Meanwhile, the land utilization should notice The RTRW and the cooperation between local inhabitant and the government was needed indeed in the soil conservation and land rehabilitation efforts.
Key Words : Erosion, Sediment, Check Dam, GI
Analisis Stabilitas Penyumbatan Muara Sungai Akibat Fenomena Gelombang, Pasang Surut, Aliran Sungai dan Pola Pergerakan Sedimen pada Muara Sungai Bang, Kabupaten Malang
Get PDFMuara Sungai Bang di Kabupaten Malang mengalami pendangkalan di mulut sungai diiringi dengan penyempitan sungai yang dapat mengganggu lalu lintas kapal nelayan saat air surut dan dapat mengakibatkan banjir saat air pasang yang dapat merugikan penduduk karena sebagian besar daerah tersebut digunakan sebagai pelabuhan ikan. Studi ini bertujuan untuk mengetahui laju sedimentasi di muara, sehingga dapat memberikan alternatif pemecahan masalah pendangkalan dan penyempitan muara.
Berdasarkan perhitungan gelombang diperoleh bahwa gelombang dominan berasal dari arah Selatan. Berdasarkan perhitungan angkutan sedimen pada muara Sungai Bang sebesar 15369,728 m3/th;sedangkan angkutan sedimen pantai sebesar 66042,94 m3/tahun dari arah selatan dan 73790,85 m3/tahun dariarah utara. Dengan demikian, dapat diketahui bahwa angkutan sedimen yang mempengaruhi muara berasal dari angkutan sedimen sungai dengan volume budget sedimen per tahun sebesar 23117,64 m3. Oleh karenaitu diperlukan bangunan jeti sebagai bangunan pengatur sedimen di muara.
Bangunan jeti direncanakan dengan panjang 480 m, ketinggian 9,7 m dari dasar laut dengan usiaguna 16 tahun. Strategi pengelolaan muara sungai terbaik yang dapat dilakukan untuk menanggulangi masalah sedimentasi di Sungai Bang adalah dengan mulut sungai terbuka.
Kata kunci : Muara, Gelombang, Sedimen, Jet
Kajian Peningkatan Manfaat Pada Bendungan Tugu Kabupaten Trenggalek
Get PDFAt the beginning Tugu dam was planned to supply water demand and irrigation water. In this study will be reviewed on a large electric power can be generated from the utilization of the reservoir outflow discharge and increase the value of benefits when Tugu dam is used as power plant and tourism places.
Power generation at Tugu dam is planned in base load. Francis turbine is selected with optimum installed power is 400 kW, which capability of producing energy is 2,140,382.328 kWh / year. Tugu dam tourism region plans to use the land area of 9.86 hectares with cottage, water and tourist playground, swimming pool, restaurant and shop / shopping tour. Based on economic analysis conducted, can increase in the value of BCR, NPV and IRR. BCR value of 1.115 which was originally changed to 1.142; the original NPV of Rp. 36,705,066,329.00 turned into Rp.53.154.809.819,00; the original IRR 13.057% turn into 13.408%.
Key words: power generation, tourism, economic analysis
Kajian Sistem Manajemen Pengelolaan Daerah Aliran Sungai Dalam Upaya Pelestarian Sumber Daya Air (Studi Kasus: Das Bone Provinsi Gorontalo)
Get PDFThe potential of water resources Bone is the source of life for the people of Gorontalo, especially as a source of water, supply fresh water for the people of Bone Bolango. Generally in upstream of watershed use less water than the water right of it downstream, and the areas generally utilize water higher than the water use right. Excess use of water in downdstream will take from the remaining water rights of upstream. Because of these problems, it is necessary to study type of management system in related with conditions of watershed. System of incentives / disincentives is a form of integrated watershed management. The purpose of this study are to investigate the discharge quantity is used by the stakeholders, determine the required operational discharge in conservation the watershed, and establish the policy in watershed management with a system of incentives / disincentives.
Keywords: Water Right, Incentives, Disincentive
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