Judul: Economic valuation of land use changes in Wonogiri Watershed (case study at Keduang Sub-Watershed, Wonogiri Regency)
Abstrak: multifunctions of agriculture land use is loss, i.e. economic function, social function and environment function. Economic function consist of loss of crop production and loss of farmer’s income. Social function consist of loss of farmer’s job and Environment function consist of erosion and sedimentation mitigation and hidrology system mitigation. This research aim to know the level of land use changes in Keduang Sub-Watershed, to analysis the influences of land use changes to environment quality, especially the loss of agriculture land multifunctions, i.e. economic, social and environment functions, to know the loss of economic value of agriculture land multifunction due to land use changes and to analyse the policies goverment about land uses change, especially land use change in Keduang Sub-Watershed, Wonogiri Regency. Research method which is used is descriptive. Research location is taken intentionally (purposive), that is Keduang Sub-Watershed with consideration that Keduang Sub-Watershed is the widest Sub-Watershed in Wonogiri Watershed with very high erosion danger index and closeness of high river stream also, so that have big generated erosion potency. Besides, from the number of precipitated sediment in Wonogiri Reservoir point, Keduang Sub-Watershed give the biggest contribution of other Sub- Watershed in Wonogiri Watershed. Data Types which are obtained are secondary data from Forestry Research and Development Agency, Surakarta, BPS of Wonogiri Regency and Agriculture Department of Wonogiri Regency. Method of analysis’s data which is used in this research is Universal Soil Loss Equation Method to predict the soil erosion. To calculate the value of economic and social function of agriculture land use multifunction used market price and to calculate the value of environment function, this research used Replacement Cost. Results of this research are: the level of land use change (since 1993 up to 2008) in Keduang Sub-Watershed is 297 hectare. The loss of economic value of multifunction agriculture land in Keduang Sub-Watershed is equal to Rp. 13,2 billion/year or Rp 44,5 million/hectare/year. The economic value of water is equal Rp 760 billion/year. The value consist of value of economic function is equal to Rp 3,7 billion/year, value of social function is equal to Rp 1,2 billion/year and value of environment function is equal to Rp 8,3 billion/year
Keyword: 

Judul: Study on the dynamic land use impact in Wanggu watershed to sedimentation to Kendary Bay in South East Sulawesi
Abstrak: The dynamic of land use in Wanggu Watershed had been causing land degradation disruption of hydrological function of the watershed and sedimentation in Kendari Bay. These degradations were indicated by the increasing of river fluctuation and erosion was higher than the local tolerable soil losts. The impact of erosion had further decreased land productivity, farmer’s income, and also increasing sedimentation in Kendari Bay as well. The objectives of this research were 1) to identify the biophysical characteristics of Wanggu watershed. 2) to study the impact of land use dynamic on erosion, run off, river flow fluctuation and sedimentation in Kendari Bay, 3) to develope land use models and agrotechnologies that can increase soil infiltration capacity, decrease run off coefficient, river flow fluctuation, rate of erosion and sedimentation in Kendari Bay, 4) to formulate land use planning and agrotechnology model in Wanggu watershed to guarantee sustainable land management. This research was carried out in September 2009 to August 2010. The result of this research showed that forested land characteristics were much better than those with other land uses particularly the characteristics that related to hydrological function of watershed. There were a continuous decrease forest land (1.1% per year) and bushes land (0.8% per year) but on the other hand a continuous increase of mixed plantation land (1.1% per year), dry land use (0.4% per year) and settlement area (0.4% per year). These dynamic giving the impact to increase erosion rate (12.7 tons/ha), surface run off (262.7 mm), run off coeficient (0.13) since 1992-2010, and in turn increase sedimentation rate in Kendari Bay. The source of those sediment come from land erosion 104.000 m3 per year (9,3%), from waste 21.310 m3 per year (2%), and river bank erosion-infrastructure-landslide 954.000 m3 per year (88,7%), to make total sedimentation in Kendari Bay was 1.071.000 m3 per year. The existing land use of Wanggu watershed in 2010 could not guarantee sustainable land management. The alternative land use planning for sustainable Wanggu watershed management is 33 % forest, 44 % mixed plantation,9% dry field, 1% bush and 13% settlement. The land use management in mixced plantation should be under Agrosilvopastoral with perennial crops (cacao, pepper, citrut fruit, banana, teak, elephant grass+3 cows), and in dry field should be under multiple cropping system(corn + cassava + peanut) - (green beans + legume + tomato). To increase productivity of both systems, the using of chemical fertilizers, manure, and compost should be applied as necessary.
Keyword: 

Judul: Rumus parameter bagi persamaan super pythagoras
Abstrak: Tripel bilangan bulat positif yang memenuhi persamaan Pythagoras disebut tripel Pythagoras. Misalkan u dan v adalah parameter dari bilangan asli, maka kita dapat menunjukkan bahwa (x, y, r) dengan rumus parameter x = -v, y2uv, dan adalah tripel Pythagoras. Penanıbahan suku atau pangkat dalam persamaan Pythagoras menghasilkan persamaan yang kita sebut persamaan Super Pythagoras sebagai berikut: dengan 22 dan kan Jadi persamaan Pythagoras adalah salah satu bentuk persamaan Super Pythagoras. Masalah yang dibahas dalam tulisan ini adalah mencari rumus parameter yang ideal, yang memenuhi persamaan Super Pythagoras (PSP). Rumus parameter bagi PSP yang berpangkat dikatakan ideal jika sebanyak mungkin memenuhi sifat bahwa rumus parameternya berlaku bagi PSP dengan jumlah saku sesedikit mungkin dan dapat diekspansi, serta sesedikit mungkin fungsi-fungsi parameter yang sama dalam rumusnya. Pencarian rumus parameter yang ideal bagi persamaan Super Pythagoras merupakan masalah baru dalam teori bilangan. Menurut Cong Philip, yang mengkhususkan diri mempelajari teori bilangan, masalah ini diperkenalkan oleh Ke Cao pada tahun 1967 dalam salah satu suratnya. Ke Cao menyatakan bahwa persamaan Super Pythagoras penting dalam teknologi di abad mendatang. Rumus-rumus parameter yang berhasil diturunkan adalah rumus yang mengandung satu parameter dan dua parameter, yang berlaku bagi persamaan Super Pythagoras dengan tingkat 2, 3, 4, 5 dan 6. Beberapa hasil pengamatan dari runus-rumus parameter tersebut adalah sebagai berikut: • Rumus satu parameter umumnya lebih ideal daripada rumus dua parameter; semma rumus satu parameter dapat diekspansi • Umumnya, rumus parameter yang diperoleh semakin kurang ideal apabila tingkat PSP semakin tinggi. • Setiap PSP dengan pangkat tertentu mempunyai rumus dua parameter yang barkarakter menyolok (ada nilai x, yang sekawan dengan nilai r). • Ada nilai x, dalam PSP, yang diberikan oleh rumus parameter yang ideal, yang merupakan kelipatan dari pangkat PSP-nya
Keyword: