Judul: Raw water for drinking water management model based on watershed
Abstrak: Growth of population at Babon watershed area has influenced the demand of raw water significantly and it also causes burden to land use. Population growth consequently will rise the demand for housing, for this reason paddy cultivation and forest area were converted to be a housing area. The effect of housing development will escalate the degree of coefficient run off (CRO). Accordingly, infiltrations of rain fall decreases and it affects the lessening of soil water contain. Besides, population growth and housing development contribute significantly to the decease of water quality surrounding Babon watershed area. Study published by Ministry of Public Work described that in the last 10 years, the damage of watershed is critical and it significantly increase drastically. Data shows that in year of 1995, 20% of watersheds which located in Java island are in critical condition. Extensively in year 2005, the number of critical watershed increase to be 60%. To overcome this situation, conservation of watershed is extremely required, otherwise, in the future population in jawa island will face the lack of raw water. The Raw Water for Drinking Water Management Model Based on Watershed is created in order to overcome the impact of critical watershed condition which influence lack of water quantity and to increase the quality of water. The Model consists of three sub model such as: sub model of raw water supply, sub model of raw water demand and sub model of water quality which has been validated based on structural validation and performance validation. Hence, this model will relevant to apply at other watersheds. By designing a “Raw Water for Drinking water Management Model Based on Watershed”, it is identified that conservation will increase the index of Coeffisient Run off (CRO). If CRO increase, it will influence water infiltration. Hence, supply of raw water as base flow will increase accordingly. The increasing of base flow, will reduce debit of surface water. Along with inceasing of debit, conservation will also increase the index of water quality. hence raw water supplied by watershed will be in category of raw water for drinking water which is called ABAM. If water quality getting better, it will minimize the cost of drinking water production. As a result, the profit of PDAM will increase significantly and it will contribute to fund conservation. In order to ensure that this model can be implemented by stake holders, It also completed by institutional mechanism. By designing institutional mechanism, consequently all stakeholders which are responsible for watershed conservation will work simultaneously.
Keyword: coefficient run off, Watershed, Raw Water, Conservation, CRO

Judul: Pengembangan model alokasi air untuk mendukung optimal water sharing: Kasus DAS Cicatih-Cimandiri, Kabupaten Sukabumi, Jawa Barat
Abstrak: There are many stakeholders in Cicatih watershed ranging from farmer to water industry laborers. In relation to the water resources stakeholders in the Cicatih watershed, the more stakeholders are the higher its potential to becoming conflicting each other. However, the most prevalent conflict is among industrial and domestic use; as according to the socio-economic survey, water uses conflict tend to erupt whenever spring water that already been utilized by local people then subsequently also utilized by water company that make shortage water for local people. The conflict ever erupted since ten years ago and has increased since 5 years ago. So as to minimize conflicts, the proportion of water use by water users need to be more transparent. The objectives of this research are: (1). Characterization and analysis of water availability and identification of effects of land cover change and the influence trend of climate change on water availability, (2). Characterization and analysis of water demands (agriculture, domestic, and industry) at various scenario water use models, and (3). Development of OptiWaSh software as an optimization model to develop recommendations of optimal water-sharing between sectors to minimize water use conflicts. The analyses using the optimization approach gave the following results. Using Verhulst projection model, the population of Cicatih Watershed could be nicely projected from 1971 through 2030 with a value of r2=0.98932. The total population in 1971 was 546 402 persons to become 1.047.164 persons in 2030. The result of trend analysis on climate variability, represented by the increase in temperature, decrease in rainfall and debit, as well as the increase in evapotranspiration through Mann Kendall analysis gave the indication of the climate change trend in Cicatih Watershed. To minimize conflicts of water use required an optimal distribution among water users, by applying the concept of optimal water sharing. To realize the optimal water-sharing concept has been developed OptiWaSh model that can be used to calculate the optimum water demands. This model has the objective function to maximize the added value of water use with the constraint that the population needs to be fulfilled. On the condition of business as usual with existing water management systems, application IP300 can only be done until 1999, whereas IP200 until 2020, and IP100 until 2028. This condition can be anticipated if the water demands to be optimized to obtain the optimum allocation of water use using the OptiWaSh model. Applications of OptiWaSh model shows that the optimum allocation of water demand are: (a) For one cropping the optimum allocation ranged from 29.5% to 30.0% (domestic), from 6.3% to 6,9% (non bottled water industry/NBWI), and from 63.2% to 64.2% (agriculture), (b) For two cropping, the optimum allocation ranged from 25,3% -25,5% (domestic), 3,7% - 3,8% (NBWI), and 70,7% - 71,0% (agriculture), (c) For three cropping conventional irrigation, the optimum allocation ranged from 17,8% -17,9% (domestic), 2,7% - 2,8% (NBWI), and 79,6% - 79,7% (agriculture).
Keyword: Watershed, West Java

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
Keyword: