Judul: Pengaruh Perubahan Tutupan Lahan DAS Cisadane Hilir terhadap Kualitas Air Sungai Cisadane Hilir Kabupaten Tangerang, Banten
Abstrak: The land usage pattern surround the Cisadane watershed has changed year to year on Cisadane watershed especially at down segment. The change of land usage has effected the quality of water physically, chemically and biologically. The decrement of water quality has relation to the utilization of water resource at Cisadane Watershed especially at down stream. The water resource utilization might be for industrial, husbandry, agriculture land and setlement purposes. Those utilizations duct the wastes to the stream. It could disturb the utilization of clean water. The evaluation to the types of land cover change and water quality of down stream of Cisadane for several years, is needed in order to determine the effect of land cover and water resource utilization to the quality of water. This study is aimed to analyze the impact of land cover to Cisadane watershed especially at the down stream during 2005-2008, examaine the water resource utilization at Cisadane down stream and account the pollution load which is approviate to the sources of contaminants and the carriying capacity. Therefore this study is expected that it can be input of information and give contribution to the management of Cisadane watershed for the some years a head. The condition of Cisadane stream at the transition area of middle part to the stream down is included as the moderate up to worse criteria with the score of WQI 60, 09 – 34,45 while the mouth area of stream is included as worse up to strongly worse with the WQI 57, 56 – 17, 72. The condition is worse nearer to the mouth part. It is caused by the accumulation of pollutant from the downstream and middle stream. The 100% of respondences (180 people) agree that the quality of Cisadane stream water nowadays is in bad condition. They state that Cisadane water is not proper to be used directly for daily purpose, such as for cooking, drinking, bathing and washing. But some of them (56, 67%) still use the water for washing the clothes and bathing. Based on classification result, there are eight land use on Cisadane Watershed area. Land use changing happened in forest, mixed garden, recident area, rice field, fisheries area, bare land, and fields. Land use change on Cisadane watershed area connected to water quality on this area. Some parameters that can used to know the water quality are water temperatures, TDS, BOD, COD, DO, nitrate, ammonia dan nitrite. Based on Classification result on assesment of sources of air, water and land pollution, residencial and industry area were the major producer of liquid wastes on this area. It can be seen from increasing of water pH, COD and BOD parameters. Based on calculation result, the highest pollutant load is mostly predicted coming from some sources (people and husbandry). The TTS is 187.809,23 ton/year, BOD is 36.767,65 ton/year, COD is 18.302,23 ton/year, TN is 1.372,7 ton/year and TP is 166, 39 ton/year. Pollutant load from people and husbandry on Cisadane watershed area for COD,TN parameter still on minimum capability and over capability for BOD, TP and TSS parameter.
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Judul: Pengaruh Perubahan Tutupan Lahan dan Pemanfaatan Sumberdaya Air terhadap Kualitas Air Sungai di Daerah Aliran Sungai Cisadane Segmen Hulu
Abstrak: Increasing the number of residents in the Cisadane watershed area upstream segment cause high river water use and land cover changes. This negative impact on the incidence of pollution load and the source of pollutants/waste that may affect the water quality of rivers and indirectly affect the level of river water pollution. The water quality is very depend on the effort to meet the needs of water for each utility. Therefore, research on the effects of land cover change and water resources utilization of river water quality in the Cisadane watershed upstream segment needs to be done. This research was conducted in the Cisadane watershed area upstream from June to August 2009. Equipments used, such as water quality data, land cover, population, utilization of river water, debit, and livestock. The instrument used is a Arcview 3.2 program and MINITAB release 14. Data processing is done by analysis of land cover change, analysis of changes in water quality, pollution load, pollution load carrying capacity, the analysis of public understanding, and study the influence of land cover changes on water quality. During the period 2005-2008 land cover changes in the Cisadane watershed area upstream shown by the decrease of forest area (72.88%), shrubs (88.18%), open land (91.14%), and the fields ( 97.52%), and increasing plantation area (102.46%), and residential (34.21%).Utilization of river water in the Cisadane watershed area upstream was quite high. For 93% of the 190 families interviewed using Cisadane River for MCK. Pollutant sources that can be seen is garbage (16%) and wastewater (30%). The dominant pollution load comes from domestic waste (4067.86 tons/month 4129.80 BOD and TSS) and livestock waste (3.24 tons/month of BOD and 17.05 tons/month TSS). This pollution load exceeds the capacity for BOD pollution load of each month and it ranged from 2484 tons/month to 3801 tons/month, while for TSS pollution load capacity not exceeding pollution load for each month. Changes in land cover and use of river water affects river water quality. This can be demonstrated by increasing in TDS (18 mg/l), BOD (20.8 mg/l), phosphate (0.303 mg/l), and COD (38 mg/l) which tends to exceed water quality standards. If viewed based on key parameters of water quality (BOD, COD, TSS), the correlation of test results on the α level 0.1 also could be concluded that there is a relationship between changes of land cover with water quality, although the significance level is relatively small. The icreasing of water quality parameters caused the decrease of Water Quality Index from 85,58 to 73,66, but the condition of the waters is still relatively moderate to good.
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Judul: Konstruksi aritmetika kurva eliptik F(2m) supersingular dan non-supersingular untuk skema kunci publik ElGamal
Abstrak: Algoritme ElGamal adalah salah satu algoritme kunci publik dengan aritmetik modular p yang mempunyai struktur grip siklik Z(p). Tingkat keanaman algoritme ini terletak pada pemecahan masalah logaritme diskret dari Z(p). Akan tetapi, tingkat keamanan tadi tahun ke tahun semakin menurun yang disebabkan kemampuan pemecahan algoritme diskret semakin meningkat. Untuk memenuhi tingkat keamanan yang memadai dibutuhkan p yang cukup besar yang menyebabkan proses enkripsi dan dekripsi menjadi lambat.
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