Fatin Nihal

Mohiuddin Sakib

Wasif-E-Elahi

Dr. Anisul Haque

Dr. Munsur Rahman

Rifath Ara Rimi

Model Domain

Bay of Bengal

Grid

Grid Properties:

Maximum Orthogonality = 0.67

Maximum Grid Resolution = 1408 m

Minimum Grid Resolution = 222 m

M smoothness = 1.21(maximum)

N smoothness = 1.02 (maximum)

Maximum M size = 1164 m

Minimum M size = 263 m

Maximum N size = 1704 m

Minimum N size = 186 m

Maximum Aspect Ratio = 1.93

Bathymetry

Figure : Bathymetry with polder in the study region

Cyclone Track Source: Indian Meteorological

Department (IMD)

Cyclone Track Parameter:

1. Cyclone time and date (YYYY-MM-DD-HH)

2. Cyclone zone or region

3. Track Location ( Latitude –Longitude in degree)

4. Wind Speed ( in knots )

5. Pressure Drop ( hPa / mbar)

6. Radius of Maximum wind ( nm)

7. Eye diameter (nm)

Brief Description on Delft Dashboard:

Upstream Boundary : Discharge Stations

Ganges: at Hardnge Bridge

Meghna: at Bhairab Bazar

Brahmaputra: at Bahadurabad

Downstream Boundary :

Water Level Station

Model Calibration

Water Level data from our model is then compared with BIWTA measured data

Reliability of our each model run is calculated from the following equation

Reference: Haque, A., Salehin, M., Rahman, M., Sumaiya, Kabir, R., Alam, S., Rezaie, A.M., Ahmed, I., Ahmed, H., Kadir, N., Jisan, M.A., “Reliability analysis of dynamic models”, in writing for the Journal: Water, June 2014.

Morphology Model Validation Location

Morphology Model Validation Result

River

name

Station name Measured

erosion/deposition

rate (cm/month) (For a

long Period of data which is

more than 10 years)

Model

erosion/deposition rate

(cm/month) (Only for

the base year condition)

Reliability

%

Bishkhali

(CES)

BIS16 -0.0122 0.1912 49.26

BIS15 -0.1426 -0.1504

BIS14 -0.4637 -0.4430

BIS12 0.3157 0

BIS11 0.0083 -0.0837

Lower

Meghna

(EES)

ML2 -0.7832 0 41.80

ML5 0.2265 -0.0023

M12 -0.2471 -0.0010

Rupsa

(WES)

RP10 -0.9200 -0.2532 50.86

RP13 -0.6169 -0.3153

RP14 (n/a) -0.3492

Overall Model reliability over the estuarine systems 47.30

Storm Surge Model Calibration and Validation

Study Area Including SIDR Track and Model Validation Location

Methodology of this Study

To compute future inundation for SIDR like Cyclone future coastal land elevations are generated from

morphology model for the year 2025,2050,2075 and 2100.

Inundation Image

Figure : Inundation area due to SIDR and SIDR-like cyclones

Inundation Area Comparison

Polder Overtopped Image

Conclusion

• Central coastal region of Bangladesh is more vulnerable against storm surge flooding due to net land subsidence in future.

• More polders are likely to be overtopped in future in this region due to the occurrence of SIDR like cyclone.