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Tingkat sedimentasi di muara S. Jelitik sangat tinggi sehingga ketika air laut surut, kapal-kapal tidak dapat keluar masuk ke Pelabuhan Perikanan Nusantara (PPN) Sungailiat. Untuk menangani masalah tersebut, pemerintah secara periodik melakukan pengerukan yang berbiaya tinggi. Oleh karena itu, Pemprov Bangka Belitung merencanakan membangun infrastruktur pengendali sedimen. Dalam perencanaan infrastruktur pengendali sedimen diperlukan data-data karakteristik sedimen dasar. Saat ini kajian khusus karateristik sedimen dasar di kawasan ini masih belum ada. [A1] Oleh karena itu dilakukan kajian ini dengan tujuan mengetahui pola sebaran karakteristik sedimen dasar seperti berat jenis, tekstur sedimen, ukuran d50 butir sedimen dan analisis stastik sedimen dasar. Karakteristik ini sangat penting untuk kajian sedimentasi selanjutnya terutama sebagai data masukan perhitungan kecepatan sedimentasi baik secara analitik maupun dengan pemodelan numerik. Metode yang digunakan dalam kajian ini adalah survei lapangan, pengambilan sampel sedimen dasar, analisis laboratorium dan analisis statistik sedimen. Berdasarkan kajian ini sedimen dasar di perairan Sungailiat ini didominasi oleh pasir sedikit campuran kerikil dengan nilai d50 berkisar antar 1-1,5 mm dan terpilah buruk. Kondisi sedimen dasar berupa pasir mempunyai daya dukung yang baik untuk pengembangan pelabuhan.Sedimentation in the S Jelitik estuary is very high, so when the tide is low, the ships traffic at the Sungailiat Fisheries Port is disturbed. So far, dredging has been done to solve this problem, which requires high costs. To overcome this, the Provincial Government of Bangka Belitung plans to build a sediment control infrastructure. In planning the sediment control infrastructure, sea bottom sediment characteristics data are needed. Currently, there is no specific study of se bottom sediment characteristics in this area. Therefore, this study was conducted with the aim of knowing the distribution pattern of seabottom sediment characteristics such as density, sediment texture, d50 grain size and analysis of the basic sediment statistics. This characteristic is very important for further sedimentation studies, especially as input data for calculating the sedimentation velocity both analytically and by numerical modeling. The methods used in this study are field surveys, sediment sampling, laboratory analysis and sediment statistical analysis. Based on this study, the seabottom sediment in Sungailiat waters is dominated by sand, a little mixture of gravel, with d50 values ranging from 1-1.5 mm and poorly segregated. The seabottom sediment in the form of sand have good capacity for port development.

Jelitik River is the main river and economic artery of Sungailiat District, Bangka Regency. Currently around the Jelitik River there is a Jelitik Fishing Port and is developed as an industrial area. In addition to the problems of sedimentation problems with the development of industrial estates and the presence of sand mining rich in tin ore on land and on the high seas it is feared that it will reduce the quality of the environment, especially the surrounding sea water. Therefore, this study is needed in order to find out the quality of waters in this estuary which can be used as a basis or baseline for the initial environment of this region if later this area will be developed as a port or industrial area. The method used in this study is field observation, water sampling, and laboratory analysis. Therefore, as an initial step, it is necessary to identify the quality of the waters in this estuary which can be used as the basis or initial environmental baseline of this area if later this area will be developed as a port or industrial area. Based on observations in the field of laboratory analysis of water samples, generally the quality of seawater around the estuary of Jelitik River still meets seawater quality standards both for port activities, marine tourism and for biota. Some parameters that exceed the quality standard include total suspended solid (TSS) which reaches 250 mg/l, total dissolved solids (TDS) which reaches 24,700 mg/l and nitrate content which reaches 0.38 mg/l. BOD value is 4.7 mg / l and COD is 46.4 mg / l, these parameters are still below the existing sea water quality standard.

Cilacap, located on the south coast of Java Island, is an “oil and gas city”. Cilacap has many oil refineries, storage, and loading & unloading facilities. However, these facilities’ existence is threatened by the potential for earthquakes and tsunami in Cilacap because Cilacap is very close to the Eurasia and Indo-Australian plates’ subduction zone. The earthquake and tsunami waves can damage these facilities and cause secondary disasters, namely oil spill pollution. The first step to anticipate is to predict the direction and distribution of the oil spill due to tsunami through simulation and numerical modeling. This simulation and modeling used the TUNAMI model, hydrodynamic model, and spill analysis model based on the worst-case scenario (Mw 9.0 earthquake). This study simulates and models the oil spill in the west and east monsoons. Based on this simulation and modeling result, we know that the direction and distribution of the oil spill in the west and east monsoons are relatively the same and move more dominantly in the current direction. The spread of the oil spill caused by the tsunami was faster than the oil spill in general. Some of the oil spills spread inland more than 1 km north of the Teluk Penyu coast. The authors expect this study’s results can be used as material for preparing of contingency plans for handling oil spills to minimize negative impacts.

Since 2014 sedimentation at the estuary of Jelitik river, Sungailiat, Bangka has continued to increase. At this estuary, the ship traffic is very busy and there is National Fisheries Port Sungailiat. When the tide is low, the river mouth closes thus disrupting ship traffic. The Bangka Belitung Provincial Government is currently planning to build a sediment control infrastructure to reduce the sedimentation rate. To plan and determine the effectiveness of the jetties requires knowledge of sedimentation patterns around Jelitik estuary. Therefore this study was conducted to determine the pattern of sedimentation (distribution and rate) at the existing and ultimate conditions. The methods are field survey, analysis of field data, and computational modeling of sediment transport. Modeling of sediment transport was done using the Sand Transport Module of MIKE 21. Two scenarios were simulated for the existing and ultimate conditions. Based on this modeling, the sedimentation rate at Jelitik estuary is found uneven. In the existing condition, a large rate of sedimentation occurs on the southern side of the Jelitik River estuary, which reaches a maximum value of 2.75 m/year, with an average of 4.44 cm/year. Whereas in the ultimate condition, the sedimentation rate decreases to 0.0377 m/year.

ABSTRA K Saat ini untuk memenuhi kebutuhan energi listrik pemerintah mencanangkan program pembangunan pembangkit listrik 10.000 MW. Salah satu implementasinya dengan membangun Pembangkit Listrik Tenaga Uap (PLTU) berbahan bakar batubara seperti PLTU Sampit di Kabupaten Kotawaringin Timur, Propinsi Kalimantan Tengah. Permasalahan utama kegiatan PLTU adalah suhu air buangan yang jauh lebih tinggi dari suhu perairan di sekitarnya. Kenaikan suhu iniselain akan mengurangi efisiensi system pendinginan juga dapat membahayakan kehidupan aquatik. Untuk meminimalkan dampak perlu dilakukan pemodelan adveksi/dispersi panas sebelum dilakukan pembangunan PLTU. Dengan pemodelan ini akan diketahui sebaran panas buangan PLTU sehingga sejak awal dapat dilakukan upaya-upaya untuk mengurangi dampak negatif yang muncul. Selain itu model ini dapat dipakai sebagai bahan pertimbangan dalam penentuan lokasi intake dan outfall sistem air pendingin. Studi ini dilakukan dalam beberapa skenario dengan menggunakan perangkat lunak MIKE-21. Berdasarkan hasil pemodelan diketahui bahwapola arus di perairan sekitar PLTU Sampit lebih dipengaruhi pasang surut dan debit sungai dari hulu. Pada musim timur, suhu air pada lokasi intake cukup terpengaruh oleh suhu air bahang pada outfall khususnya ketika air laut pasang. Perubahan temperaturair pada intake berkisar antara 30,1 – 32 o C. Kenaikan tertinggi terjadi ketika air menuju pasang naik maksimum. Pada musim angin barat, suhu air pada lokasi intake hanya sedikit terpengaruh oleh suhu air bahang pada outfall, perubahan temperatur air pada intake hanya berkisar antara 29,99 – 30,1 o C. Kenaikan tertinggi terjadi ketika air menuju pasang naik maksimum. Resirkulasi air pendingin dengan intensitas cukup besar (+ 2 o C) diprediksi terjadi saat air pasang. Hal ini dapat menjadi lebih parah bila debit sungai dari hulu berkurang yaitu ketika musim kemarau. Kata kunci : dispersi panas, PLTU, air bahang, intake, outfall ABSTRA CT Now to comply the electricity needs, government announced the construction of 10,000 MW power plant. One of its implementation by building Steam Power Plant (PLTU) with coal-fired power such as Sampit in the District of Eastern Kotawaringin, Province of Center of Kalimantan. The main problem of power plant activities is the waste water temperatures much higher than the temperature of the surrounding waters. The rise of temperature will not only reduce the efficiency of the cooling system but also be harmful to aquatic life. To minimize the impact needs to be done advection/dispersion modeling of heat water prior to the construction of the power plant. With this modeling will be known distribution of heat waste from power plant in 2-dimensional, so that can be done since the beginning of efforts to reduce the negative impacts that arise. In addition, this model can be used as a consideration in the determination of the location of the intake and outfall system cooling water. This study was conducted in several scenarios using software MIKE-21. Based on modeling results is known that the current pattern in the waters around the Sampit power plant is more affected by tidal and river flow from upstream. In east monsoon, the water temperature at the intake is quite affected by the heat water temperature at the outfall especially when high tides. Water temperatur changes in intake ranged from 30.1 to 32 o C. The highest increase occurred when the water toward the maximum high tide. In the west monsoon, the water temperature at intake only slightly affected by the heat water temperature on the outfall. Eater temperatur changes on the intake only ranged from 29.99 to 30.1°C. The highest increase occurred when the water toward the maximum high tide. Recirculation cooling water with considerable intensity (+ 2°C) could occur during high tide. It can be more severe if the river flow from upstream is reduced like as at the dry season. Keywords : thermal dispersion, steam powerplant, heat waste water, intake, outfall Citatio n : Wibowo, M., Hendriyono, W., Nugroho, S., Al Hakim, B., Velly Asvaliantina. V. (2017). Kajian Dispersi Panas Dampak Rencana Pembangunan PLTU Sampit-Kotawaringin Timur Propinsi Kalimantan Tengah. Jurnal Ilmu Lingkungan, 16(1), 86-97, doi:10.14710/jil.16.1.86-97

To overcome many problems in Jakarta such as: flood, tide flood, lack of water resources and land, the government decided to build a giant sea wall (GSW). Development GSW on Jakarta Bay is a form of intervention of technology on the water sea environment, so its will surely had an impact especially to the water sea quality (BOD, DO and salinity). Aim of this study is to know magnitude of sea water quality changes due to the construction of GSW .This study was conducted with computation modeling using software MIKE-2,1 Eco Lab module. Based on this study, GSW development will give significant impact to sea water quality especially waters in the formed polder. The quality of waters in formed polder significantly decreased, especially of the value of BOD . Value of BOD is rise more than 100 % and value of DO is decrease more than 20 % andsalinityis decrease more than 2 percent .To prevent a trend of decreasing the sea water quality in Jakarta Bay that caused GSW development, must be done with prevention act from upstream part before the waters entrance to Jakarta Bay.

The developmentof the international port of Patimban in Subang is very urgent. The port is expected to support the Tanjung Priok port in Jakarta which is unable to meet the loading and unloading needs of business operators, especially in West Java. In port development planning one of the main problems of physical chemical aspects is sedimentation and erosion process. The purpose of this modeling is to know the sedimentation and erosion pattern around the location plan of port development. The result of modeling is expected to be the initial consideration in designing the Patimban Port. Modeling of sediment transport is done by using MIKE21 Sand Transport module software by entering geophysical data of field survey result such as bathymetry, sea level, river flow and characteristic of existing sediment. Modeling is done both in west season and east season for 1 year (October 2016-September 2017).Based on the results of this modeling is known that the existing conditions in parairan construction plan ponds occur sedimentation sedimentation of 12.74 cm / m th while when the port has been built a little erosion -0.34 cm / year. Whereas in the existing shipping lane plan there is sedimentation 14,41 cm / year and when the port has been built there is sedimentation of 6,06 cm / year.