Team Memeber
Md. Sazzad Hossain, Raihanul Haque Khan, Dilip Kumar Gautam, Ripon
Karmaker, Md. Amirul Hossain
Presented by
Sazzad Hossain
Flood Forecasting and Warning Center
Bangladesh Water Development Board (BWBD)
Dhaka,Bangladesh
[email protected]
www.ffwc.gov.bd
Motivation
Location and topography made the country vulnerable to Flood hazard
Too much water in Monsoon - FLOOD
Max 68% area
flooded in 1998
Milestones with Floods from 1954 to 2014
7 major FLOODS since 1954
1998
About 3% to 5% of the GDP
30%
25%
2007
1987
1974
1955
15 times 25% or
more area affected
2004
1988
loss with each FLOOD
In 2014
25%
area
flooded
for 3 to
4 weeks
Bangladesh rivers receive runoff from a catchment of
1.72 million sq-km, around 12 times its land area
Brahmaputra Basin
552,000 sq.km
CHINA
BHUTAN
Ganges Basin
1,087,000 sq.km
INDIA
Bangladesh
INDIA
BANGLADESH
Meghna Basin
82,000 sq.km
BAY OF BENGAL
Research Objectives:
 Application Basin scale Hydrological Model
 Development of seasonal flow outlook
 To share experience of Bangladesh with others
 To explore the opportunity in improving seasonal
scale forecast
 Joint collaboration with other research
organizations
Hydrological Characteristics of River Basins
Ganges
Max Q 78,000 m3/ s
Min Q 200 m3/ s
Brahmaputra
Brahmaputra
100,000 m3/ s
4000m3/ s
Max Q
Min Q
Meghna
India
Ganges
Lower Meghna
Max Q 180,000 m3/ s
Bay of Bengal
Min Q
4,000 m3/ s
Hydrological Characteristics
1.Brahmaputra
– Flood PeaksJune September)
2.Ganges
(Flood PeaksAugust September)
Flood Forecasting Approach in Bangladesh
5-days deterministic forecast
based on observed water level data as boundary condition at
different points along the Border of Bangladesh
 uses MIKE11 model
10-days probabilistic forecast
based on discharge forecast boundary condition at Hardinge
Bridge on Ganges River and Bahadurabad on Brahmaputra
River
uses ECMWF EPS rainfall forecast, CFAB-FFS model
(Hydrological Model) and MIKE11 model
 Seasonal flow outlook (Experimental)
(ECMWF Seasonal (6 Month) Precipitation
Forecast)
Some Potential Applications of Seasonal Outlook
Decision making for agricultural undertakings
(seed-bed preparation, planting, harvesting)
Fishery Protection and Management
Livestock Protection and Management
Disaster Management Planning
Water Resources utilization planning
(e.g., Irrigation water use planning)
Meteorological forecast information for Seasonal
Hydrological outlook
Monsoon Information
(IMD,BMD)
Long Range Forecast for
Rainfall (IMD)
South Asian Climate
Outlook Forum
(SASCOF)
Monthly Rainfall
Forecast (Bangladesh
Meteorological
Department)
Seasonal Flow Outlook Model Development:
Approach & Methodology
1) Extract ECMWF seasonal ensemble (41)
forecast of rainfall and temperature for the
Ganges and Brahmaputra basins
2) Compute ensemble mean for each grid
3) Compute Mean Areal Precipitation (MAP) and
Mean Areal Temperature (MAT) over the
catchment
4) Set up rainfall-runoff model (HYDROMAD)
with MAP and MAT as input (Model simulate
for 3 Month Period)
5) Calibrate and validate the model for historical
period (Model simulate using data- only Since
2012)
Modelling Approach
Hydromad Model
 Lumped model
 Hydromad is an R package
The modelling framework in the hydromad package:
For Ganges,
SMA: Catchment Wetness Index (cwi),
Routing: Exponential Unit Hydrograph (expuh)
For Brahmaputra,
SMA: Catchment Wetness Index (cwi),
Routing: Auto Regressive Moving Average
(ARMAX)
Preliminary Result
Ganges
Brahmaputra
Correction Applied: ARIMA correction
1
Ganges
Brahmaputra
Model Experimentally Operated – from Monsoon ,2015
Evaluation: only for May-July,2015 (details evaluation will be
done at the end of 2015 )
Ganges – R2= 0.72, NSE=0.59, Brahmaputra- R2= 0.78,
NSE=0.61
Dissemination Approach
Generate advisory and disseminate through Webbased (http://sffs.rimes.int) Decision Support System
(i)Observed
flow,
(ii)Normal flow
and
(iii)Forecasted flow
Conclusion and Recommendations
 Details Evaluation is necessary
 Preliminary Result shows promising prospect
of seasonal outlook
 Presently mean ensemble value has been used
 Seasonal Rainfall Forecast should be Evaluated
 Spatially Distributed Model (Mike Basin,
LISFLOOD) may be used
 Upstream Hydrological information is
necessary for model calibration
 Prepare a meaningful format seasonal outlook
for end users
Thanks you for your attention