Hidrodinamika Tanggul Raksasa Teluk Jakarta & Pulau Reklamasi Dialog Publik: Kebijakan Reklamasi, Menilik Tujuan, Manfaat & Efeknya Auditorium KPK, Jakarta, 04 Oktober 2016
Widodo Pranowo & Tim Kajian Reklamasi Pusat Penelitian dan Pengembangan Sumberdaya Laut dan Pesisir
http://p3sdlp.litbang.kkp.go.id
Kondisi Batimetri Teluk Jakarta
Sumber: Balitbang KP (2016)
2 Skenario • PerGub 01/2012 • Masterplan NCICD Garuda Great Wall
Jaringan Pipa dan Kabel Teluk Jakarta
PIPA GAS KABEL SUDAH DIREKLAMASI PROSES REKLAMASI
Sumber: DISHIDROS 2016, Diperbarui oleh Balitbang KP 2016
JGSW Period I (2010‐2020) with height of 1‐3 meters or 3‐6 meters along north coast of Jakarta & there will be a highway on top of it
PPS NIZAM ZACHMAN
JGSW Period II (2020‐2030) with height of 1‐3 meters or 3‐6 meters integrating reclamation islands & there will be a highway on top of it
WATER GATE
PPS NIZAM ZACHMAN
JGSW Period III (After 2030) with height of 3‐6 meters closing/protecting Jakarta Bay & there will be a highway on top of it
WATER GATE
PPS NIZAM ZACHMAN
Tidal Current Simulation Before JGSW Built
Tidal Current Simulation After JGSW Built
Small islands is potential eroded & dissapear Accumulation of Waste, Sediment, & freshwater trapped in basin
Pola Arus rata‐rata bulan Januari sebelum ada pulau reklamasi
Kecepatan arus rerata di sepanjang pantai teluk Jakarta 0.2 – 0.3 m/detik, lebih kecil dari kecepatan arus di mulut teluk 0.3 m/detik
Sumber: Balitbang KP (2016)
Pola trajektori cemaran/sedimen yang bersumber dari muara sungai di Teluk Jakarta saat musim barat (Jan‐Mar)
Garis jejak cemaran/sedimen yang bersumber dari sungai‐sungai yang bermuara di Teluk Jakarta cenderung untuk bergerak dalam arah barat‐timur di sekitar pantai, untuk itu kualitas lingkungan di perairan di sekitar pantai Teluk Jakarta akan berubah secara signifikan jika jarak minimum antara pulau reklamasi dengan daratan atau antar pulau reklamasi diabaikan
Sumber: Balitbang KP (2016)
Pola trajektori cemaran/sedimen yang bersumber dari muara sungai di Teluk Jakarta saat musim timur (Jul‐Sep)
Garis jejak cemaran/sedimen yang bersumber dari sungai‐sungai yang bermuara di Teluk Jakarta cenderung untuk bergerak dalam arah barat‐timur di sekitar pantai, untuk itu kualitas lingkungan di perairan di sekitar pantai Teluk Jakarta akan berubah secara signifikan jika jarak minimum antara pulau reklamasi dengan daratan atau antar pulau reklamasi diabaikan
Sumber: Balitbang KP (2016)
Arus pasang surut antara Pulau G dan kanal inlet PLTU/PLTGU Muara Karang 1. Percepatan arus pasang surut yang diakibatkan oleh terbentuknya Pulau G sebagaimana ditunjukkan oleh scatter diagram di titik 1 dan 2 2. Di dekat ujung kanal inlet (titik 3) terjadi perubahan arah arus pasang surut, dari yang semula barat daya‐timur laut menjadi tenggara‐ barat laut dan cenderung mengakibatkan terjadinya aliran air yang dari outlet PLTGU ke mulut inlet
Kajian Dispersi Termal di sekitar PLTU Muara Karang akibat adanya perubahan pola arus
1. Keberadaan pulau G berpotensi meningkatkan suhu air laut di inlet PLTU/PLTGU Muara Karang hingga 1,5°C 2. Keberadaan pulau H dapat meningkatkan suhu air laut hingga 0,5°C
Backwater Impact (Kenaikan Level Muka Air)
•
Risk of impacting hinterland flood levels as a result of the reclamation changing the backwater in the various rivers and canals a major concern of the authorities and public, – Eastern sector has a mean level rise at the discharge point > 10cm (equivalent to 40 years of sea level rise). The consequence of this impact on mean level at the discharge points will have greater probability of hinterland flooding and higher area of impact when flooding does occur. – Tanjung Priok development has negligible impact on backwater levels at the adjacent discharge points. This can be expected as the reclamation is a seaward expansion of an existing development. – Further west the impacts are smaller than those encountered in the eastern sector but are still in the order of 5cm (equivalent to 20 years of sea level rise) and thus still viewed as a risk factor. – For the western end of the development, impacts are found to be small (< 1cm). It is not certain if this is real or due to lack of data and choice scenario and must therefore still be viewed as an issue as far as the REA is concerned.
•
Mitigation preferably through modification of reclamation boundaries, otherwise dredging (at least ‐4mCD) which is then associated with higher maintenance/cost Sumber : DHI, 2016
Fig. 1. An overview of Jakarta Bay and the development phases of the construction of a Giant Sea wall similar to the Master Plan of National Capital Integrated Coastal Development. Differentiation can be made between land reclamations of phase A (cross‐hatched), phase B (gray), and the closing of the eastern reservoir in phase C (dotted lines). Pumping stations are placed to control the water level of the western and eastern reservoirs by pumping water from the reservoirs to the sea (black dots). Jakarta city limits topography © OpenStreetMap‐contributors.
Wulp et al. 2016
River discharges and nutrient loads Cisadane River (36 ± 17 m3/s)
Citarum River (137 ± 64.2 m3/s)
• River discharges defined for the flow model were taken from the hydrological model. A total average discharge of 205 ± 97 m3/s flow to Jakarta Bay distributed over 13 rivers and streams (Cisadane, Cengkareng, Banjir Kanal Barat, Muara Angke, Muara Baru, Ciliwung, Sunter, Cakung, Blencong, Banjir Kanal Timur, Cikarang‐Bekasi‐Laut (CBL), Keramat, Citarum).
Wulp et al. 2016
River discharges and nutrient loads Citarum River (46%)
CBL (12%)
Ciliwung River (18%)
River TN flux was chosen as the potential driver of possible eutrophication effects. TN loads for individual rivers were quantified based on river discharges, river water quality measurements taken in October 2012 and calibration of simulated nutrient gradients in Jakarta Bay. TN loads ranged between 39 and 174 tons/d with an average of 91 ± 45 tons/d. The highest TN loads entered Jakarta Bay through the Citarum River (46%) followed by the Ciliwung River (18%) and CBL (12%). Wulp et al. 2016
River discharges and nutrient loads Citarum river (51%)
CBL (17%)
Ciliwung River (13%)
• TP loads ranged between 14 and 60 tons/d with an average of 31.9 ± 15.7 tons/d. The highest TP loads entered Jakarta Bay through the Citarum river (51%), followed by the CBL (17%) and the Ciliwung River (13%).
River discharges and nutrient loads
Sunter River (11 ± 7 kg/d)
Ciliwung River (16 ± 8 kg/d)
• DEET loads were in the order of 44 ± 23 kg/d, of which the highest loads were found for the Ciliwung River (16 ± 8 kg/d) and Sunter River (11 ± 7 kg/d). Wulp et al. 2016
Fig. 3. Annual averaged total nitrogen (TN) concentrations for the reference scenario (a), initiated land reclamation of phase A (b), construction of the Great Garuda and closing of the Western reservoir during phase B (c), and completion of the initial design with closure of the eastern reservoir during phase C (d).
Fig. 4. Comparison of simulated annual averaged TN concentrations of all scenarios along transect A–A' crossing the western reservoir (top), transect B–B' in between the western and eastern reservoir (middle), and transect C–C' crossing the eastern reservoir (bottom). Wulp et al. 2016
Fig. 5. Annual averaged total phosphorus (TP) concentrations for the reference scenario (a), initiated land reclamation of phase A (b), construction of the Great Garuda and closing of the Western reservoir during phase B (c), and completion of the initial design with closure of the eastern reservoir during phase C (d).
Fig. 6. Comparison of simulated annual averaged TP concentrations of all scenarios along transect A–A' crossing the western reservoir (top), transect B–B' in between the western and eastern reservoir (middle), and transect C–C' crossing the eastern reservoir (bottom). Wulp et al. 2016
Fig. 7. Annual averaged N,N-diethyl-m-toluamide (DEET) concentrations as a molecular marker for municipal wastes for the reference scenario (a), initiated land reclamation of phase A (b), construction of the Great Garuda and closing of the Western reservoir during phase B (c), and completion of the initial design with closure of the eastern reservoir during phase C (d).
Fig. 8. Catchment areas of the Jakarta Metropolitan Area adjacent to the western and eastern reservoirs. Wulp et al. 2016
