Judul: Aplikasi Model Tangki untuk Pendugaan Neraca Air dan Laju Sedimentasi menggunakan Metode MUSLE di Sub DAS Lahar Kabupaten Blitar
Abstrak: Lahar Sub-Watershed has the elongated shape of the river with a narrow width whereas the main river has 16.86 km length. Under these conditions affect the distribution of water flow to the downstream. Tank Model is one of the hydrologic models that is able to estimate the distribution of water flow either vertically or horizontally. To estimate the sedimentation rate using MUSLE method, which the erosivity parameter in this method is run off data from Tank Model. In order to know distribution of water flow at Lahar Sub-Watershed so used Tank Model. Application of this model is an attempt in a better management of Watershed. The purpose of this researches is to estimate the characteristics of water balance in Lahar Sub-Watershed and to estimate the sedimentation rate using Tank Model application and MUSLE method. This research is located in Lahar Sub-Watershed, Blitar, East Java that has an area of 1418.80 ha. Land cover in Lahar Sub-Watershed consist of 261.58 ha natural forest, 905.46 ha farm field, 54.96 ha agricultural field, 63.76 ha rice field, and 133.04 ha residential area. Soil types in Lahar Sub-Watershed is consist of grey andosol and grey regosol association, grey regosol and brown latosol association, reddish brown mediteran and brown regosol with undulated until mountainous topography and the elevation between 291 ̶ 1093 mdpl. The average temperature in this area between 23.3°C with the highes temperature is 34.7°C and the lowest is 19,2°C, it was a B3 and C3 climate type. Result of the calibration data obtained correlation between water level and water flow, y=6.238TMA1.495 with R2=0.918 and correlation between water flow and sedimentation rate y=43.56Q2.118 with R2=0.853. Total of rainfall in 2009 is 1702 mm/yr and in 2010 is 3304 mm/yr. Total of observation sedimentation rate in 2009 is 12366 ton/yr or 8.7 ton/ha/yr and in 2010 is 20180 ton/yr or 14 ton/ha/yr. Result of Tank Model optimation obtained R=0.65 and water balance, the rainfall is 2590 mm/yr, the evapotranspiration is 797 mm/yr, and the outflow calculation is 1308 mm/yr that distributed through surface 203.5 mm (15.56%), intermediate flow 324.5 mm/yr (24.82%), sub-base flow 520.8 mm/yr (39.83%), and base flow 258.7 mm/yr (19.79%), so the value of storage is 479 mm/yr. Result of the MUSLE method obtained formula R2=0.631. It is shown that MUSLE model could estimate sedimentation rate well. Total of sedimentation rate from June 1st until May 31th 2010 is 26899 ton/yr (19 ton/ha/yr or 1.6 mm/yr). This indicates that sedimentation rate in Lahar Sub-Watershed included to medium category.
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Judul: Pendugaan Neraca Air Menggunakan Aplikasi Tank Model dan Laju Sedimen dengan Metode MUSLE di Sub DAS Melamon Kabupaten Malang
Abstrak: Brantas Watershed is important in fulfilling the requirement for water and energy in East Java Province. The management of Brantas Watershed has been less optimum. Therefore, a model is required to help portray the distribution of water flow and the movement of sediment in a particular watershed. Such application like the Tank Model which is based on River Flow Observation Station is deemed to have the ability to predict the river flow both horizontally and vertically as well as with the ability to determine the pace of sediment in particular areas by utilizing method Modified Universal Soil Loss Equation (MUSLE). The objectives of this research are to assess water balance both vertically and horizontally in the study area by utilizing Tank Model using SPAS data as baseline, and to acquire the exact rate of sediment with the method of MUSLE by using runoff coefficient for optimization result of Tank Model. The research was conducted at SPAS Jedong, Sub Watershed Melamon, Brantas Watershed in the upstream, Sub-District Wagir, Malang Regency. The total of research area the site was 886,785 ha, located between 7°57’46’’ Lalitude – 7°59’39” Lalitude and 112°30’22” Longitude – 112°34’36” Longitude, with sloping and mountainous topography at altitude between 542 m a.s.l – 1.681 m a.s.l. According to the geology’s formation, the research area comprised of young volcanic rocks and ashes with soft structure as well as sandstone. The typical of soil was dominated with andosol (64%) and kambisol (36%). The climates’s classification follow Oldeman, classification C3 and B3 (Source: Monitoring and Evaluat on of BPDAS Brantas 2010). Data processing was carried out the Laboratory of Hydrology of Forest and Watershed, Department of Forestry Management, Faculty of Forestry, Bogor Agricultural University. Based on the Tank Model, the obtained coefficient of correlation was 0.60 and the run off coefficient that become the initiation of hydrograph result was 18%. within 365 days, the optimization result of Tank Model resulted in the total amount of rainfall of 2,317 mm, evapotranspiration as 1,166 mm, total outflow of 651 mm devided into surface flow 119 mm (18%), intermediate flow 247 mm (38%), sub-base flow 208 mm (32%) and base flow as much as 77 mm (12%) so that there is water saving as much as 499 mm. MUSLE method acquired such equation Qs= 0.006x, with koefission determination value a much as R2= 0.683, this proves MUSLE model could predict the sediment pace quite well. The total amount of sediment flow in Sub Watershed Melamon from June 2009 to May 2010 was 0.76 mm/year. This indicated that sediment flow in Sub Watershed in Melamon was relatively good.
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Judul: Prenilasi Senyawa β-Diketon sebagai Prekursor 3-Prenilflavon
Abstrak: One group of flavonoids that has not been commonly synthesized is 3- prenylflavone. The main objective of this experiment was to synthesize precursor of 3-prenylflavone. Firstly, β-diketone was synthesized via 4 steps from phenol as starting compound with total yield of 24%. Prenylation of β-diketone with prenyl bromide and K2CO3 base produced 4 fractions which were separated by using preparative thin layer chromatography (PTLC) with n-hexane:EtOAc (8:2) as the eluent. Fraction with Rf = 0.80 was further separated by using preparative PTLC with n-hexane:EtOAc (99:1) as the eluent. Two fractions were obtained with Rf = 0.38 and 0.42. The first fraction has been characterized as diprenylated β-diketone with 49% yield. Application of protecting group on the phenolic OH group in β- diketone are needed to obtain monoprenylated β-diketone which can be further cyclized into 3-prenylflavone
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