Judul: Perencanaan Penggunaan Laban untuk Pembangunan Pertanian Berkelanjutan di DAS Lahumbuti Sulawesi Tenggara
Abstrak: Land use which is not compatible with land capability and lack of awareness to apply soil conservation measures, are the causes of increasing erosion and decreasing soil productivity which ultimately lead to low income of the farmers. Therefore, there is a necessity for proper land use management plan, particularly in the Lahumbuti catchment for achieving sustainable agricultural development. The research that has been conducted in Lahumbuti catchment. has the objectives of evaluating land use and land capability, and also le::rrning the agrotechnolo-g-; applied in the Lahumbuti catchment. Beside that, the study was also aimed at designing alternative for land use management plan which is compatible with land capability to achieve sustainable watershed management at Lahumbuti catchment. Method used in this research was survey method that comprised collection of primary data and secondary data. Primary data includes (a) physical condition of the land (steep slope and length of slope, permeability, effective soil depth, drainage, texture, stucture and content of the soil organic matter) and (b) socio-economic condition (demography, production facility, cost, farmers income and agrotechnology applied in the study site), evaluation of suitability betwen land use and land capability using Klingebiel and Montgomery criteria, erosion estimate using USLE method, calculation of Etol using Hammer method (1981 and evaluation of living standard appropriateness using Sajogyo and P. Sajogyo ( 1990 ). Secondary data are in the form of daily rainfall data, facts in the district, topographic map and soil map. Research result showed that generally land use in Lahumbuti catchment are accordance with their land capability, although there were several farming activities that were conducted on steep slope. Planting pattern and agrotechnology adopted by farmer were still traditional. Result of erosion prediction at intensive obsevation site indicates that the occuring erosion (13,03-262,10 tonnes/ha/year) were greater than the soil loss tolerable (8,65-48,% tonnes/ha/year), resulting in decline of land productivity and farmers low income (Rp. 2.822.650,- - Rp. 8.033.100,- HH/ha/year). Therefore, there is need for change in cropping pattern and agrotechnology, accompanied with soil conservation measures so that erosion could be reduced to a minimum level which is smaller than the tolerable level. Pursuant to equality of land capability class and types of cultivated crop betwen the intensive observation sites and the land units at the whole of Lahumbuti catchment, land use recomendation in the catchment is that at land class I (21.870 ha) and land class II (1213,5 ha) the suitable land used are mixed garden and dry land, there would be inter cropping (tumpangsari, tampang si1>ip) and multiple cropping, accompanied by mulch and construction of bund terrace. Forest and shrubland could be converted to mixed garden and dry land or agroforestry system. Land class III (11.624,1 ha) and class IV(28.373,7 ha) are
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Judul: Studi Perencanaan Pengelolaan DAS dengan Model Optimasi Penggunaan Lahan di Bagian Hulu DAS Mahakam
Abstrak: Land use which is not in accordance with the land capability, will cause land degradation. In Indonesia, there is progressive increase of critical land area size, every year, and this exerts an impact toward watershed damage. Objectives which are sought in the planning of watershed management often negate each other because from one point of view, there is a desire to maintain natural resources sustainability, and from other (economic) point of view, there is a desire to increase farmer's income. In order to obtain a model for planning sustainable watershed management, land use optiminazation was conducted and designed using the analysis of Linear Goals Programming (L GP) The study area had the size of 29 686 ha, comprising 3 subdistricts (namely Damai, Barong Tongkok and Melak) that were situated in the district of Kutai Barat, the province of East Kalimantan. The formulation of model for land use optimization was designed to achieve four targets, namely peak discharge. reduced rate of erosion (so that it is equal with or smaller than the targeted discharge and tolerable soil loss), ability of each farmer family to fulfill the need for food and rice, and ability of on farm income to create appropriate level of welfare. Research unit was homogeneous land unit. Data source for model input came from improvement of cropping pattern and alternative agrotechnology which was conducted by using simulation of CP factor. Data processing and analysis used the method of SCS, USLE and farm analysis. On the other hand, the completion of model used software General Algebraic Modeling System (GAMS) and Arcview 3,2. Land use with existing cropping pattern gave peak discharge of 116.39 m3/seconcj, erosion between 157-876 tonlha, production of upland rice 1.52 ton GKPlhalyear, and income Rp 3 268 636,-halyear. On the other hand, optimum land use pattern from the six scenarios model, showed better results as compared with the existing condition because ecologically, the land use could maintain the stability of peak discharge, and reduce erosion to the level below the targeted value. Although scenario model la and llla (with land use composition in the form of non irrigated rice field and dry land crop field) gave better result than those of existing conditions, but the occurring erosion were still higher than those in scenario model I, 11, Ill, and IV (with land use composition in the form of non irrigated rice field, dry land crop field, and estate field). This was because the priority for achieving erosion target in scenario la and llla was only up to the tolerable rate of soil erosion. Testing of scenario model I, 11, Ill, and IV showed that there was a tendency for increasing proportion of dry land crop field area size, but on the other hand, decreasing proportion of non irrigated rice field and estate field area size, if the target of achieving living standard is continuously increased. Spatially, recommendation that could be given for /and units of non irrigated rice field, dry land crop field and estate field is in the form of cropping pattern and agrotechnology LI *, L3b* ,
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Judul: Grup dan Homomorfisma Grup pada Rubik Revenge
Abstrak: Rubik cube is a kind of puzzle game. A player must arrange rubik sides, which have been disordered, back to the position where every side has the same colour. This paper does not focus on the settlement solution, but instead on proving the existence of a group homomorphism between rubik movement group and S96 symmetric permutation group in rubik revenge. Firstly, it has been proved that rubik movement set is a group. Then, it also has been proved that the M set, which contains numeric labels of 1 until 96 in cubinos sides, is S96 symmetric permutation group.
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