Modelling of the heated water spreading in MuaraKarang 9A$ ffi rnoc rrB, yoL 3t, No. t, tses g coastal waters, Jakarta Bay D K. Mihardja, M.S. Fitriyanto and M.R. Putri Department of Geophyslcs and Meteotology, lnstitut Teknologi Bandung Jln Ganesha 10 Bandung 401 32 Received: October 1998 ; revision received: March 1999: accepled: March 1999 Abstract Modellilg of the heatcdrvateti sprcadingin .lakarta l3ay hud trccn perlbnucd as a part of'the study ou coolirg watcr circulatiou ol' Muara Karang l)orver Plartt, North.laklrta. 'l'hc results ol'thc sirnulatiou descrrbed in this papcrillustlatcdlbr cast season (August 1994), triursitional scason (November1995), and wcst seasou (Januarl' 1996).'l'hc spreading of thcmral water in Muara Karang coastal watcrs ncar the outlet canal ol thc powcr plant tbr each season and all tidal and wind conditions is dominantly inllLrcnsed bydischargcofcoolingrvaterthatltastuaxiururnvalueof15.lurr/scc Iuthclart-rcldareathesprea<-tilgrsdirectedbl,lxrlsoorr (*rrtd-induced) currelttsand slightly inlluenccd by tidal currents. I'hennal watcr u,hich sprcadsout lionr the outlet caual into coastal rvatcrs has a tnittitnutn area ofabout 58.60 hcctares in transitionalseason at hrghcstwater level, and a nraxirnuui area of' about 156 hectares in transitional scasou u'lren water levcl gocs to cbb. hr gcncral, the sinrulationrcsults in thc cast scason are comparable to the obscrved data, rvhilc in the transitional season ofcast-wcst season iurd in tle west seasou thc urodel rs still beins veritred. 1Q'yv'ords: coastal re<:lantaliott; coolingv'alcr circulalion; llrcmtol sprcading. Sari Pemodelan penycbaran air hrngat dari pcmbangkit listrik tcnaga uap di perairan Muara Karang, Tcluk Jakart ^ Pcrnodelatt sebaran panas di 'Icluk Jakartautenrpakau salahsatu bagiandari studi rcsirkulasi air pendingiu l'L'l'tJ lduara Kararrg, Jakarta Lltara.Hasil sirnulasi pada rnakalah ini menggambarkan kondisi pada musirn tinrur (Agustus 1994), rnusirn pcralihau (November 1995), dan rnusitn barat (Januari 1996).Scbaran tennal di perairanMuara Karang dckat saluran outlet PLTII untuk rnasing-masing tnusim dan sernuakondisi pasang surut dan aurgin sangat dominan dilrcngaruhiolch dcbit I,LTI.J yang nraksirnunr l5,l rllr/dctik. Di daerahjauh, arah scbaran tcnnal bergantung pacla arus urusinr(pengaruh angin) dan scbagian dipcnganrhi oleh pasallS surut. Tcrnpcratur air pauas yang keluar dari saluran orrlicl rncnycbar kc pcrairandcngan luas ntiniurrun 58,(r0hektar pada rnusim pcralihart pada saat air pasangrnaksimuur, dan luas rnaksirnun sckitar 156 hektar pada nrusinrperalihan saat air menuju surut. Secara utnuut hasil sirnulasi pada musirn tiurur yang dibandingkan dcngan data lapanganharnpir sesuai, scdangkan pada ntusim peralihan dari ntusiui tirnur kc ntusinrbarat dan padanrusiru baratrnasih akan divcrillkasi lcbilt lanjut Kalo kntci: rekkrnosipantai; sirkulosi air petnlingitt;sebarorr tcmnl. I Introduction In the frarnc work of study on cooling rvatercirculation of Muara Karang (North Jakarta) Pou,er Plant rvhich airns to evaluate the impact of coas(alrcclamatiou near the plant, a sinrulation of heated wa(er sprcading havc been perfonned in the Muara Karang coastal waterstllat is a part of Jakarta Bay (seeFigure 2). Thc final goal of lhe study is to try to find out the solution of a conflict of iutcrest between the owner of lhe potvcr plant and the developer who lms reclaunted lhc coastalarea near the plant. Horveverthis paper is rvritten bascd on the progress rcsults. So, the abovernentioned solution is not yet described in the paper and rvill be implicd in the final result tlnt is being finalised. The authors havc analyzcd simulation resuhs in the east. west. and transitional seasons, and have conrp:lred nrodel sinrulation in the east season with obscrved data Frour the cuvironmentgl point of vierr,, Burharruddin (1989)Itadstudied an inrpact of thcrnralpollutantfrour lhis power plant on marine biota in this coastal \vaters area (see also Mahlan, 1984 aud Martouo, 1984). Burlmrtuddin had concluded that only fishcs, crustaceans. aud rnollusca are tolerallt lo high temperature and can live in the hot cuvironrncnt. The highcst telnpcrature tolerated by fishes is 38.1"C, by crustaceans is 37.9'C and by rnollusca is 36.7"C.