Potential of Sibsa River for establishing a new port.pptx

It is a presentation based on the potential analysis of sibsa river for etablishing a port

1. 7 th International Conference on Civil Engineering for Sustainable Development (ICCESD-20 24 ), 7 ~ 9 February 20 24 , KUET, Khulna, Bangladesh POTENTIALS OF SIBSA RIVER FOR DEVELOPMENT OF A NEW PORT IN TERMS OF NAVIGABILITY Presented By Rezwanur Rashid- Assistant Engineer,Mongla Port Authority Co-Authors Motiur Rahman - Executive Engineer, Mongla Port Authority & Ph.D Student , KUET Prof . Dr. Md. Shahjahan Ali – Department of Civil Engineering, KUET Department of Civil Engineering Khulna University of Engineering & Technology

2. INTRODUCTION The Pussur-Sibsa system is a multichannel system within the southwest It flows partly through the Sundarbans and consists partly of a heavily modified delta plain. Approximately 30 km from its mouth the river diverges into the Sibsa River (west branch) and Pussur River (east branch). Pussur River Sibsa River Mongla Port Akram point 30km

3. INTRODUCTION The Mongla Port (MP) is situated on the east bank of Pussur river, at around 80 km upstream from Akram point. The Pussur river's depths were adequate for an average of 8.5m draft ships at the time of Mongla Port’s establishment. However, after 1980, the depths were drastically reduced. Mongla Port Akram point 80 km Several dredging efforts had been made to restore the navigability of the Pussur River since 1979. But none of the dredging attempts could maintain an effective passable channel because of the high siltation rates

4. INTRODUCTION Akram Point is the confluence point of Pussur and Sibsa river. The cross-section at this location on the Sibsa river shows that the depth of the river is 34m CD whereas in the Pussur river depth is 24m CD. Sibsa river is tidally very active compared to the Pussur river in terms cross-sectional area, depth and tidal volume. Akram point

5. INTRODUCTION Government of Bangladesh has established another sea port on Ramnabad channel named Payra Port which is around 70 km east of Pussur-Sibsa estuary. 70km Ramnabad channel Payra port Pussur-Sibsa Estuary Bay of Bengal The Port has an almost 75 Km long outer channel which is too shallow for arrival of ships and a designed canal needs to be dredged and maintained to a particular level that is safe for passage.

6. INTRODUCTION This presentation will demonstrate the suitability of Sibsa river for development of new port in terms of Hydrodynamics and Morphology of the river .

7. STUDY AREA The study area focused on Pussur-Sibsa River system Starting at Khulna on north and Bay of Bengal on south. The Sundarban also falls within the study area. Two types of tidal river system were considered: 1. primary (Pussur and Sibsa) and 2. connecting channels (tidal channels linking primary rivers )

8. METHODOLOGY Analysis of hydrographic profile of both primary river Study of several report to assess annual maintenance dredging quantity Approximate cost analysis of dredging

9. RIVER GEOMETRY GBM Delta Gorai River Pussur-Sibsa 85% Modhumoti- Baleshwar 15 %

10. RIVER GEOMETRY Connecting Rivers Between Pussur and Sibsa Solmari ( Batiaghata ) Jhapjhapia ( Pankhali ) Chunkuri ( Dacope )

11. RIVER GEOMETRY Dacope Akram Point

12. HYDRODYNAMICS In comparison to Pussur River, Sibsa has More tidal activity Higher tidal volume Deeper bed level Faster tide propagation Faster approach speed of tide

13. HYDRODYNAMICS River Dry Season Discharge Monsoon Season Discharge Spring Neap Spring Neap Flood (mill.m3) Ebb (mill.m3) Flood (mill.m3) Ebb (mill.m3) Flood (mill.m3) Ebb (mill.m3) Flood (mill.m3) Ebb (mill.m3)   Sibsa 186 196 100 109 305 258 306 215   Pussur 137 144.5 83 85 167.5 110 157 72   COMPARISON OF FLOW Average flow throughout the year: Sibsa river is 209.38 mill.m3 Pussur river is 119.5 mill.m3 Sibsa channel has 75% more water than Pussur channel throughout the year

14. MORPHOLOGY AND NAVIGABILITY BED LEVEL Sibsa River about 20m-35m below CD Pussur River about 5m-20m below CD

15. MORPHOLOGY AND NAVIGABILITY Figure: Bed profile of the Pussur river along the thalweg line Chalna Joymonirgoal 5m-7m 15m-25m

16. MORPHOLOGY AND NAVIGABILITY Figure: Bed profile of the Sibsa river along the thalweg line Chalna Constantly deep bed level

17. DREDGING AND COSTING In Pussur river five major dredging projects has taken place from 1990 to 2023. The MPA has conducted capital dredging of 330 million m 3 and maintenance dredging of 53 million m 3 . Total expenditure was 10 billion BDT approximately. To maintain the 7.5-8 m CD, About 5 million cubic meters of annual dredging is required. Yearly expenditure of this dredging will be 1.75 billion BDT approximately.

18. DREDGING AND COSTING Most part of Sibsa river has sufficient depth for movement of more than 10m draft ship Only the entrance of Pussur-Sibsa river has to be dredged which is common for both Pussur and Sibsa river . The dredging volume will be 1 million m 3 approximately . Maintenance Dredging of inner channel will be almost negligible compared to 4 million m 3 of Pussur river.

19. DREDGING AND COSTING In Payra port , The port area has sufficient depth to accommodate ships with 10m draft but the outer channel spanning around 75 km in length which currently suffers from insufficient depth to address ship arrivals. A channel must be regularly maintained to ensure a safe passage for vessels. Approximately 9.75 million cubic meters of sediment has been extracted from the outer channel in order to create a canal with a width ranging from 100 to 125 meters . This excavation process has incurred a cost of 5 billion BDT .

20. CONCLUSION The operational and maintenance cost of Sibsa river will be less than the existing Mongla port or Payra Port. The hydrodynamic and morphological features of Sibsa river are in more advantageous status than Pussur River or Ramnabad Channel. However , hinterland connectivity to be improved, specially bridges over Chunkuri and Jhapjhapia river to connect with Khulna city.

21. THANK YOU