Transcript Urban Stormwater Management in Developing Countries

Strategies for adaptation of
urban drainage systems to
climate change
by
Ole Mark, DHI
Urban Stormwater Management
in Developing Countries
Jonathan Parkinson
Ole Mark
IWA Publishing
2005
www.iwapublishing.com
ISBN: 1-843390-57-4
Relationships between areas of development,
urban catchments and river basin
Conceptual framework and operational structure
for IWRM
Main components of integrated urban water
management
Stormwater drainage - an integral component of
urban environmental management
The priorities of a city ?
1.Drinking water
2.Sanitation / sewers
3.Wastewater treatment & reduction of
flooding
4.Reduction of pollution in recipients
5.Recreative values of water
Dubai
Excessive amounts of litter in a drainage channel in Dhaka
Source: Urban Stormwater Management in Developing Countries, 2005
Photo: Birgitte Helwigh
Blocked inlet to the stormwater drainage system in Dhaka
While waiting for the next flood in your city…
Karachi, Pakistan – 19th August 2006
Power supply,telecommunication,moblie systems disrupted
Rain related death toll: 26
Rain: 50-60 mm…..
While waiting for the next flood
in your city…
Urban poor living on the banks of an urban river in
Jakarta, Indonesia
Causes and types of urban flooding
Today, the model is a copy of the
city….
Final grid with streets
and buildings
Raising by 5 m places
where there are buildings
Grid with streets
Lowering by 20 cm places
where there are streets
Initial elevation grid
Modeling of flooding in cities
What is flooded ?
What does flooding cost ?
Direct Damages
Traffic Planning
Flood damage reduction
1. Land use planning
2. Reduction of the flood extent
3. Reduction of the interaction with the flood
4. Control of the surface runoff and
subsequently flooded areas
5. Emergency plans and actions
6. Flood warning and information systems
While waiting for the next flood in your city….
Do you believe in climate changes ?
• Will a 10 year rain become a 2-3 year
rain ??
30 years => 5 years ?
• Can/will we ”build” fast enough ??
• What do we do - When we get
flooded ?
Climate change
This should be avoided…
This was the control of a
pumping station 
Flooding computed for a new “climate” 10 year rain
The football field in Greve
Flooding computed for a new “climate” 10 year rain
The football field as flood strorage…
Beijing – 2004
How should we handle extreme
rain fall and climate changes in
the urban areas?
Climate change
Informed
decissions!!!
So while you are waiting for the climate
changes and the next flood in your city –
spend some time to think about:
1. What will be flooded ?
Climate changes
2. What will it cost ?
3.How can damages be reduced ?
4.Can you learn something from
other places ?
ManagmentSummary
of climate changes
Climate changes
Today
• Analyses of urban
flooding
• Climate & Risk/Hazard
analyses
In the future
• Timely management
(climate, planning, costbenefit, etc)