Judul: Aplikasi Model Tangki dan Pendugaan Erosi dengan Metode MUSLE Berbasis Data SPAS di Sub DAS Sibarasok Gadang Kabupaten Padang Pariaman
Abstrak: Flow distribution in a watershed is a dynamic process and very dependent on climate, precipitation and combination of land coverage, evapotranspiration rate, soil type and topography of the watershed. Hydrologic biophysic process in a watershed is a natural process as a part of the hydrologic cycle. Change of watershed hydrological condition can result disaster such as floods and landslides. Application tank model is a hydrological model that used to predict river flow characteristic by using data from the SPAS. The research located at Sibarasok Gadang Sub watershed, IV Koto Aur Malintang Sub-District, Padang Pariaman District, West Sumatra. Data was processed at the Laboratory of Forest Hydrology and Watershed, Department of Forest Management, Faculty of Forestry, Bogor Agricultural University. This study aims to examine the distribution of water flow horizontally and vertically using a Tank Model and examine rate of sedimentation in the Sub-watershed Sibarasok Gadang used MUSLE method. Stages of research include analysis of the relationship river flow and water level, processing of rainfall data, river flow, and daily evapotranspiration, and analysis of sediment and erosion rate. Total rainfall during the research is 1,575.6 mm. The results equation between Water Level and Discharge in SPAS Sibarasok Gadang was Q = 7.724 TMA 1,585 with R² = 0.968, correlation between discharge and sediment rate was Qs = 0.525 Q , with R2 = 0.971. Correlation between sediment rate observation and sediment rate MUSLE model showed a high correlation with regression equation was QsMUSLE = 4,287 QsObservasi + 0,005 with R2 = 0.788. This proves MUSLE models can be used to predict the sediment rate reasonably well. Tank Model optimization results obtained parameter values R2 = 0,816. Total flow horizontally into the river dominated by base flow of 679.861 mm with a percentage of 73.10%, followed by the intermediate flow of 16.08%, 7.21% of surface flow and sub-base flow with the smallest percentage of 3.61%. It means the capacity of infiltration is high. Water level shows the flow vertically with the highest water level in tank D (base flow) of 1378.095 mm, followed by tank B intermediate flow (47.979 mm), C sub-base tank flow (18.097 mm), tank A surfaceflow (1.456 mm). This situation shows the condition of the Sibarasok Gadang Sub Watershed is still good.
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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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