Urban Flood Risk Management in a Changing Climate: Sustainable
and Adaptation Chanllenges
6-10, Sept, Macao, China
URBAN FLOOD AND INUNDATION IN HANOI CAPITAL
PLOBLEMS, MEASURES AND CLIMATE CHANGE
ADAPTATION
TRINH THU PHUONG
VIETNAM NATIONAL CENTER FOR METEO-HYDROLOGICAL FORECASTING
- HaNoi capital of Vietnam
- Located in Red river Delta.
- Area: 3.324,92 km2
- Population: 6.450.000 (2009).
- Red river (the second largest
river of Vietnam) flows
throught Hanoi city, come into
the sea with annual capacity
(60 billions m3)
- The city belows the water level
- HaNoi is prevented by a solid
dykes system. The dike system in
Ha Noi has never been broke, even
in big flood years 1971, 1996 or
during the war
Total length Dyke :
3500 km
LOW DELTA
97% of delta regions with dyke < 9 m
72% of delta regions with dyke < 3 m
58% of delta regions with dyke < 2 m
Height in Hanoi:
15 m
Dyke system in Ha Noi can stand for the flood level 13.5
m, higher than III alert : 2.5m
Ubarn flood in HaNoi can be devided into two categories
1. Local flood: very hight rainfall intensity occure and
generate higher surface run –off that is in excess of local
drainage capacity. Urban Flood and Inundation will happen
Inundation
Inundation
2. Riverini flood: heavy rainfall at upstream, big
flood upstream happened and after that the
watel level at downstream increase rapidly.
Climate change in Hanoi
Dute to Climate change and global warming, HaNoi city
may effect more big flood from upstream and heavy
rainfall in city.
The temperature in Hanoi
rises up from 2000-2009
Maximum total rainfall in day at
Ha Noi rises up from 2000-2009
Total rainfall in 6 hour at Meteorological stations in
HaNoi has been increased for 10 years.
Met_hydrological network in HaNoi
Climate change in Hanoi
- Infuture, from 2010-2100, the temperature will increase 3o,
total rainfall in dret season increase 20%, and in dry season
decrease 40%
Annual Temperature and % the changes of Rainfall in HaNoi
from 2000 to 2100
Ubarnization, population growth and flood in Hanoi
- In 10 years recent, the
population of HaNoi go up
very quikly.
-The boom of urbanisation
has led the city a giant
contruction field and
inefficient solid wastes
proceesing and
consequencyly lead to
inundation and stagnage
of under ground water.
-Landuse: Many pond and low land areas or small lakes
regulation were replaced or narrowed by construction and
building which leads to the reduction of water restore
capacity.
- The rainfall runoff happen qickly exceed the capacity of
HaNoi’s drainage
Surface runoff on the road
at Nguyen Khuyen str,
HaNoi city (13/7/2010)
Depth in undation
from 0.3-0.5m
Some serious flood features in Hanoi city
in recent times
-Because of climate change, The intensity per hour and
total rainfall in a day at Hanoi trend to increase. The
inundation will occurred more than usual and takes long
time.
- From 30 October to 1 November
2008, the extremely heavy rains over
500-600mm were recorded in Hanoi
area (3 days). The rain in Hanoi was
concentrated in a short period with the
highest intensity in more than 100 years
passed.
-Deep inundation about 1,5-2,5m
during 5-10 days in Hanoi.
-10 People died in this flood.
-Total Points inundation in HaNoi are
about 30
Inundation from 0,5m-1,0m, many areas from 1-1.5m.
Boating in Ha Noi city in 2008
Traffic jam in Kim Ma street
(2008)
Hoan Kiem lake, 1 Nov 2008
Inundation 17/8/2009
The rainfall over 100mm caused
inundation in Hanoi with deep about
0,5-1,0m.
-The duration of inundation: 1days
- On the morning, 13 July 2010, from 6.45 Am to 10
Am, A heavy rainfall occurred. Total rainfall recorded in
the central of Ha Noi from 100 mm- 153mm (3 hours).
- There are 23 points inundation from 0.3 m -1m,
especially many main streets at center HaNoi.
-3 People died in Ha Noi in this inundation.
-Duration of inundation: 5 hours
13/7/2010
13/7/2010
13/7/2010
13/7/2010
Street or River?
Kim Lien Tunnel
Some main reasons of HaNoi inundation
1. The old and low capacity of underground sewage irrigation
cannot afford to discharge water when rainfall is higher than
172mm/2 days (86mm/1 days)- Stage I of the Hanoi drainage
project (supported by JICA). But infact, many heavy rain
occurred in short time with total rainfall is higher than
172mm.So, Ha Noi is always flooded
Inundation occurred in HaNoi X>86 mm/day
2.Because
of
the
ubarnization,
landscape change by
contruction. Surface
runoff on the road
appears earlier.
3. HaNoi haven’t got an ubarn flood management
system and decision maker. The contaction between
National Met-Hydrological Forecasting service and
Some oganization (responsible for water resources)
is not available.
Current status drainage of Hanoi
Four companyies have been established to assit the
responsibility water resources.
- Hanoi water Business Company, responsible for
management, operation of water supply in urban areas of
Hanoi city.
- Hanoi sewerage and Drainage Company, responsible
for operation and maintenance of the sewerage and
drainage system
- Environmental Company: collection and processing of
domestic water
- Design Copany for ubarn Public work, carriout all the
design work for distribution pipeline and home
connections
Current status drainage of Hanoi
Drainage system in Hanoi include water from rainfall and
wastewater.
Current status drainage of Hanoi
Downtown of HaNoi city:
1. The main drainage directions are To Lich river and
Nhue river.
+at To Lich basin: Pumping water to Red river by Yen So
station with capacity 45 m3/s; Dong My station and
throught Thinh Liet Dam.
Yen So station with 11 water pumps
Current status drainage of Hanoi
Downtown of HaNoi city :
+ at Nhue basin: Pumping water to Nhue river by Dong
Bong, Xuan Dinh, Thanh Binh station with capacity 23
m3/s (while need 114 m3/s)
Current status drainage of Hanoi
Downtown of HaNoi city :
2. 10 Small trenches for irrigation and 32 small river in city
gather the overflow on the road.
Measures to mitigate the Hanoi ubarn flood,
inundation and climate change adaptation in Hanoi
1. Structural measures:
Build upstream
Reservoirs (prevent Ha
Noi capital from 500
years return periods)
Strengthen the
dike system to
protect Red
riverl delta
Dredging and clearing river
bed and Constructing the
rainwater collecting works;
upgrated the drainage system
Flood
control
in Hanoi
urban
Plan and protect
upstream forests
Cooperation between National,
Province, District, commune must
be well (including infrastructures,
equipments, and operation &
management)
Some results of strutural measure for ubarn flood in HaNoi
4 big reservouirs system upstream Hong river delta have
reduced the volume of flood and maximun of watel level at
HaNoi station in flood.
Son La operated
(3 bil for flood
control)
TuyenQuang
res operated (3
bil for flood
control)
Thac Ba reservouis
operated (0.5 bil
for flood control)
Hoa Binh
reservouis
operated (3 bil
for flood control)
Measures to mitigate the Hanoi ubarn flood,
inundation and climate change adaptation in Hanoi
2. Non-Structural measures:
Urban
planning in
long time
Changing and
improving
awareness of
public involved in
monitoring the
management and
resolution of
flooding, protect
environment
Mitigate
inundation
and flood
lossed in
Hanoi
Developing the
transferation information
throught TV, radio,
webside and VOV traffic
Strengthening
of the
forecast
capacity
Flood Management
cycle
Investment project for Irrigation in Ha Noi
1.The stage I of Irrigation project in Ha Noi from
1998-2005, Japan International Cooperation
Agency (JICA) funded :
+ Resolved the inundation in HaNoi with the
rainfall less than 172 mm/2days (50mm/2h)
+ Built the drains through the dike 45m3 / s;
discharged into the Red River channel
90m3/giay; Yen So lake regulation
3.78
millions m3.
+ Dredging and river embankment 4 main small
rivers: To Lich, Lu, Set and Kim Nguu (33km).
Investment project for Irrigation in Ha Noi
2.The stage II of Irrigation project in Ha Noi
from
2008-2011,
Japan
International
Cooperation Agency (JICA) funded:
+ Increase the capacity of pump Yen So staion
from 45 m3/s to 90 m3/s (8millions m3/day)
+ Resolved the inundation in HaNoi with the
rainfall less than 310 mm/2days
+ Improved 12 regulation lakes
Investment project for Irrigation in Ha Noi
3. The project "Construction and renovation of
three pump stations and drainage Co Nhue, west
of Hanoi Dong Bong" by the Belgian
Government funding has been approved by the
city allocated to Sewerage Company Hanoi
investor. (Co Nhue pump will be built with a capacity
12m3/s, Dong Bong I, Bong Dong II pump is 9 m3/s in
2012)
Forecasting and warning inundation in HaNoi
Foreign Country:
-Project: Water quality monitoring work under dry
and wet wether conditions in the downtown of
Hanoi city, Dr. Hiroaku Furumai, Research Center
of Water Environment Technology, University of
Tokyo.
Pilot Point is downtown of Ha Noi, simulated the
inundation in 2003 and 2008.
Strengthening of the forecast capacity
In Vietnam
-Using Quantitative Pricipitation forecast
(from Numberical Weather Model, radar and
sattelite) as the input of hydrological model)
-Forecasting the water level at Ha Noi
station with the lead time from 24 hours to
48 hours using hydraclic model.
URGENT PROJECT IN VIETNAM FROM 2011-2013
-BUILDING THE RAINFAL AND FLOOD EARLY
WARINNING SYSTEMS, FORECASTING AND
WAINING DETAIL HANOI INUNDATION from 20112013.
+Modenization the Met_hydrological network observation
+Supplied the hight technology for Mydro_Meteorological
nowcasting.
- Weather forecasting in short time using HRM
and ETA hight resolution model 14kmx14km.
Pilot selection: HaNoi Capital
-Using distributed hydrological model MARINE
(French) for Flood forecasting and warnining in
short time. Pilot selection: Hong -Thai Binh river
system.
-Using hydraulic model MIKE 11, MIKE 21,
MIKE Urban and MIKE GIS Flood forecasting
and warnining in inudation in downtown HaNoi.
- Building 412 rainfall stations (28 points for
Muity-reservoirs operation
- Improvement the infrastructure for 25 hydro
stations at Hong river
-Improvement and rebuilt 127 Meteorology
auto- stationst in the North to meet the density of
stations: 30-60km
New
Auto
rainfall
stations
network
in the
Project
-Improvement and
rebuilt 127
Meteorology autostationst in the North
to meet the density of
stations: 30-60km.
- Upgrate the rain
gause network in Hanoi
for nowcasting (rainfall,
flood, inundation)
Making hazard map: flood and inundation Map in Hanoi
-Terrain survey and inundation points investigation in
HaNoi (total day Rainfall>100 mm)
Depth inundation 0.3-0.5 m
Depth inundation 0.5-0.7 m
Depth inundation 0.7-1 m
- Setting up hydrological urban model for caculating
and early wairning flood and inundation in Hanoi
- Digitize floods and inundation mapping in hight
resolution ( for all city, for districts…)
Diagram of
flood and
inundation
warning in
Hanoi
Rain gauge,
radar, settalite
Hydrological
model
forecast
Via: wesite, TV, radio,
Voice of Vietnam traffic
channel.
To: govement, central and
local, Central Committee for
Flood an,d Storm Control in
Hanoi, Hanoi sewerage and
Drainage Company
Flood bulletin,
inundation Map in
realtime
THANK YOU !