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: Water Quality of the Downstream Cisadane River and Its Feasibility as a Source of Clean Water and Dringking Water for Residential Areas
Abstrak: Sungai Cisadane memiliki fungsi dan nilai yang sangat tinggi bagi kehidupan manusia. Namun, kegiatan manusia di DAS Cisadane dan di Sungai Cisadane dapat mengancam fungsi dan pemanfaatan perairan karena dapat menurunkan kualitas air Sungai Cisadane. Penelitian ini bertujuan untuk menentukan kelayakan kualitas air Sungai Cisadane untuk air baku air minum terkait dengan dinamika akibat pasang-surut dan musim. Pemantauan di lakukan selama tahun 2020 di Sungai Cisadane bagian hilir. Parameter kualitas air yang diamati meliputi TSS, warna, kekeruhan, bau, BOD, COD, amonia, nitrat, nitrit, fosfat, total P, sulfida, Zn, Fe, As, Pb, Cd, Cu, Hg, Se, Cr6+, Mn, sianida, deterjen, dan Total Coliform. Analisis dilakukan secara deskriptif, dan dengan penentuan Indeks Pencemaran (IP). Hasil analisis menunjukan bahwa kondisi musim, musim hujan dan musim kemarau, dan kondisi ketinggian muka air yang dipengaruhi oleh pasang surut laut berpengaruh pada beberapa parameter kualitas air. Kecuali NO3, PO4, H2S, Ar, Cd, Se, Cr6+, sianida dan deterjen. Berdasarkan Indeks Pencemaran (IP) perairan bagian hilir S. Cisadane telah tercemar ringan sampai berat, sehingga air tidak dapat digunakan sebagai sumber baku air minum tanpa melalui pengolahan terlebih dahulu., The Cisadane River has a very high function and value for human life. However, human activities in the Cisadane watershed and in the Cisadane River can threaten the function and utilization of the waters because they can reduce the water quality of the Cisadane River. This study aims to determine the appropriateness of the water quality of the Cisadane River for drinking water related to the dynamics due to tides and seasons. Monitoring was carried out during 2020 in the lower reaches of the Cisadane River. Water quality parameters observed included TSS, color, turbidity, odor, BOD, COD, ammonia, nitrate, nitrite, phosphate, total P, sulfide, Zn, Fe, As, Pb, Cd, Cu, Hg, Se, Cr6+, Mn , cyanide, detergent, and Total Coliform. The analysis was carried out descriptively, and by determining the Pollution Index (IP). The results of the analysis show that seasonal conditions, rainy and dry seasons, and water level conditions which are affected by sea tides affect several water quality parameters. Except NO3, PO4, H2S, Ar, Cd, Se, Cr6+, cyanide and detergents. Based on the Pollution Index (IP) the downstream waters of Cisadane river have been lightly to heavily polluted, so that the water cannot be used as a raw source of drinking water without going through treatment first.
Keyword: Pollution index, seasons, tides, water quality

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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