九州大学学術情報リポジトリ Kyushu University Institutional Repository Water Quality in Madura Strait, Indonesia Nugrahadi, M. Saleh Department of Earth System Science and Technology, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University Yanagi, Tetsuo Research Institute for Applied Mechanics, Kyushu University https://doi.org/10.15017/16684 出版情報：九州大学大学院総合理工学報告. 25 (1), pp.7-15, 2003-06. Interdisciplinary Graduate School of Engineering Sciences, Kyushu University バージョン： 権利関係： En(grf' {lti'e,rfin,g,S,ci,e,nlsfts,R,e,psr,til,K,y,u.sRu,UHtiKveori?V'y Jte thIl Jit \ Jk \ wa me ft ge r\ cu fk ng 25g ag IZ 7-15 H rpnt 15 ff 6n VoL 25, No. 1pp. 7-15 JUNE. 2003 Water Quality in Madura Strait, Indonesia M. Saleh NUGRAHADI" ' , Tetsuo YANAGI* 2 E-mailofcorrespondingauthor:saleh riam. shu-u.ac.' (Received Jan IS', 2003) Observations on water quality based on physical, chemical and biological properties of sea surface water were conducted on 13-14 September 2000 and on 14-15 May 2001 in Madura Strait, Indonesia. Particular emphasis has been placed on Surabaya and Porong estuaries and its surrounding coastal water, where rivers carry contaminated load from land and debouch. The observation showed that Madura Strait received a lot ofpollutant from the rivers. Key words: water guality, Madura Strait, Porong river, Surabaya river, estuary 1. Introduction Wrigley and Widjanarko (1999) reported that there were many domestic and industrial sources of Madura Strait lies between East Java, Madura pollution in the Brantas river catchment. A total Island, and Bali Strait (Fig. 1). It is connected to the 13.72 million people or 429o of East Java population Java Sea through the narrow, shallow channel around presently live in the basin. Additionally, there are 20 km long, less than 15 km. wide and four meter numerous industries in the Brantas river basin, and deep, and Surabaya Harbor is situated at the center of many of them are potential polluters of the river. this channel. Surabaya is the second biggest city in Due to the pressure from industry, agriculture and Indonesia and the main harbor in the eastern part of urbanization, the Brantas River becomes heavily Indonesia. In the southern part there is an electric s J va Sea ss.f ,,.,(( itslii Madura !sland , 7"sirk&llEl.l x-t - ,c... ",. I '"t" s."E:,' i" t -7. }iiiiiil (it//k2;ff;..., asPZ .= . ,' iNDQII.)illll\,.,.,,,..Sll'!Agfi, '`" r --------..----.---- Ig bl3 ,i- "- : lliixll<iiiiiiiii,rait Ir' .t Y-} .il C; t ':' River k i l r.tl) :, ., ..,,., :,.: -7. svrabeYs tttt .: rb ttl.lt:, : ,.). ' ' ),.:. I:'" "i:,:l 1:l ,,,.JavaSea .l ) .vvt' ' t..'."t L. ",, B,:II}tSS pstk•.si..N.g.: eq yoPe. " ,UM,{..durq.,,ttqq•1't •:•k -7. East Java t: ss.,,i,,,llll.gMliilli}li;iillit. ' E': Okm 10km20 km "ft' -7. m Etectrtc. Fig. 1 Situation site of Madura Strait 112.4 112.6 112.8 113 113.2 113.4 E Fig. 2 Study area and bottom topography. Numbers show depth m meter. power plant. Madura Strait is a shallow water area with depth ranging between 1-60 m. The water depth near land is 1-5 meters, and deepens toward eastward. The steep area exists between Madura and Kambing islands (Fig. 2 ). 2ee This strait has been used for fishing, sea -Surabayariver transportation, and shrimp cultivation.' Madura Strait 7 .N lsc --mi,-- Porongriver is located at the downstream area of the Brantas river s & i 2 that diverges into the Surabaya river which passes 81ee through the heart bf city of Surabaya and the Porong b- , river which is built as flood control c.anal. The se freshwater discharge of these two rivers varies seasonally. The Surabaya river input in 1997 (Fig. 3) e was 19.4 m3!s during the dry season (average from J F M A M J- J A S O N D April to September) and 45.9 m31s during the wet Month season (average from October to April). Meanwhile, Fig. 3 Discharge of Surabaya river and Porong river in 1997. the Porong river input was 15.4 m31s during the dry season and 106.0 m'ls during the wet season. *1 Student, Department ofEarth System Science polluted, threatened by flood and draught. Afterward, the water that fiows into the estuary and Technoloby causes pollution of heavy metal (esp. mercury). However, Rochyatun (1999) showed that the "2 Research Institute for Applied Mechanics -8- Water Quality in Madura Strait, Indonesia environmental quality of the Porong estuary became spectrophotometric method (Parson et al., 1984). better based on 3 years (1992-1994) investigation. Chromium (Cr) was .measured . by atomic absorption During those years, DO increased but COD spectrophotometer method (Ernest. and Billings, decreased. On the other hand, there are several fish 1967). and shrimp ponds along the coast between the Surabaya estuary and the Porong estuary. At the moment those ponds were abandoned due to fish 3. Result disease called "white spot disease ". In this work the impact of river discharge on the estuary area and its adjacent waters is investigated. 3.1 Water temperature and salinity Sea surface water temperature (SST) 2. Method ofResearch distributions in both periods (Fig. 4) show relatiyely high SST in offshore area and low SST in near shore Field observations were carried out on 13-14, area. This is obviousl' y due to the effect of freshwater September 2000, and on 14-15, May 2001 in the discharge from both rivers. SST in September 2000 Madura Strait, East Java Indonesia. The sampling that was ranging between 27 and 310C, was higher period represented the transition period between wet than that in May 2001 that was ranging between 26 and dry season (May) and the end of dry season and 300C. In September 2000, salinity was (September). Eleven points were selected around the between 10 and 35 psu and that in May 2001 was two estuaries of Surabaya and Porong rivers and its between 5 and 27 psu. Temperature and.salinity surrounding coastal water for collecting sea surface distributions affected density distribution. Water water (Fig. 1). Those samples were analyzed in the density in September 2000 was higher than that in field or laboratory. Water temperature was measured May 2001. In September 2000, density was between directly in the field by thermometer, salinity by 4 and 20 and that in May 2001 was between 14 and salinometer and. density was calculated from 17. In Indonesia, September is the end of dry season temperature and salinity by using the program based or transition season between dry to wet monsoon. on UNESCO Sea Water Properties Standard. The daily average air temperature in Surabaya is Chemical and biological parameters were measured between 280C-330C in September. In contrast, May is in the laboratory. Total suspended solid (TSS) was the end of wet season hence the air temperature was measured by gravimetric method. Nitrate (N03), lower than that in September. This situation also silicate (Si) and phosphate (P04) were measured by happened to SST in the Madura Strait. In addition, me. , ,,. 11'1 ":t,I.:.11[1:1[.11.[,-. '""',,,.:,[.ll/ Zl zt ri ,i,i•,,28RkAMIsLAND 1O kra•J• .2eulgrimlstaND 7. 7.2 v' ljx---- •5> v 7. •k '' 7.3 g io Sk xz •7 S 7,4 Surabaya river S 7.4 Surabaya river z8 .N EAST 3AVA "• EAS'l- JAVA 7. 7. di26b porongLvllye Poroypa"rko? e s- 7. z / Temperature eC} Temperature eC} Surtace water Surtace water ' 13-14 September 2oeo 14-15 May 2001 7.7 7.7 112.6 "2.7 112.8 "2.9 113 112.6 "2,7 l 1 2.8 " 2.9 X3 E E Fig.4 Temperature of surface water rpnt15ff JL thH Jk ML"4 Jk 47 sc meapar\Wk ag 25 g ag lg -9- 7.1 Zl . okm'' le'km 2e k,m O kin URA ISIAND VRA ISI.AND 7, 7. eg:i. r x} IT. -e zliiir 7.3 ttR$ 7.3 3,V,,S.,.. -!' •l S 7.4 Surabaya river S 7.4 Surabaya river in v rvL. EAST JAVA EAST jAVA e . 7. .tskx. 7. Poreng riv Porong riv e 7. 7. $alinlty (PSV) Satinity (P$U) Surface water Surtace watef 13-l4September 2ooO 14-15May 2001 7.7 77 "2.6 "2,7 "2,8 "2.9 113 t12,6 M2.7 "2S "2,9 113 E E Fig. 5 Salinity of surface water 7, "l 7,1 ma"'ri'M "i' "" i"d' km Okm lekra 20kra UliUX ISI.AND .-i ., '' V RA ISI-AN D 7v 7. e ,$"1' /e "" 7,3 M x "" 7,3 -pt- • ,4 Z lq- el e Surabaya river Nt'}> Surabaya river S 7.4 1 $ 7.4 twtti ee EAST i JAVA EAST 3AVA . 7. 7. Porong rjv . Porong riv . 7, 7. Density <t] i> Den$ity < u i) $urtace water Surtace water 13-14 September 2eOO 14-15May 2001 Z7 7.7 X2.6 "2,7 '1 1 2,8 112.9 "3 t12.6 "2.7 "2,8 112s9 113 E E Fig. 6 Density (6t ) of surface water -10- Water Quality in Madura Strait, Indonesia 7,1• Zl -- ::/:i:1[:IIIIIII:1,l -''u. :.1.I.1.I:1[:lill-.m"v, ' ok. Aokm 2we,isill,l.lsmND ekrn lekm 2ekm URA! I$IANP Z2 tt Z2 ex,)iS"S ' t"va>e 7.3 7.3 e" in" ie sx< •in" Surabaya river iie Surabaya river k9 S 7.4 ts S 7.4 1' ig" EAST jAVA ` EASTJAVA 3.w" Z5 •-• 3' 75 tw" ' Porong riv Poreng riv . 7.