Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

URBANIZING AREAS IN THE MEKONG DELTA AND CLIMATE CHANGE ADAPTATION (PRoAA-2U)

Dr. Hong Quan (Also on Behalf of Assela, Phi, Vinh, Mohan, Willam, Berry, Quang)

Post-graduate Research Programme on Adaptation to Climate

Change in the Mekong River Basin – Phase 2 (PRoACC-2)

23- 25 July 2014 – Can Tho, Vietnam

Climate change adaptation strategy –

A road map for flood management

in Can Tho city

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

CONTENTS

PROBLEMS

EXPECTATION

CURRENT PLANS

A ROAD MAP

CONCLUSIONS and OUTLOOKS

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

1. PROBLEMS

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

1. PROBLEMS

FLOODING

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

1. PROBLEMS

High tide

Rain

High tide and rain

(SIWRR, 2013)

Flooded map in Can Tho

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

2. PROBLEMS

Water pollution (point sources, diffuse sources, sewage system, WWTP)

Flood health risk are not well considered

(Nguyen H. Q et al, 2014)

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

2. PROBLEMS

(1): open water samples; the blue circle (2): flooded and/or sewer samples; the black circle (3): flooded samples; and the brown circle (4): sewer samples

(Nguyen H. Q et al, 2014)

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

2. PROBLEMS

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

2. PROBLEMS

Recorded water levels in the river, sewer

and roads during a flood event on the 7th of October 2013

E. coli variation at three surface water

sampling locations during the flood

event on 7th Oct. 2013

(Nguyen H. Q et al, 2014)

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

2. PROBLEMS

Infection probability distributions for Salmonella of children and pedestrians

(Nguyen H. Q et al, 2014)

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

2. PROBLEMS

How to apply advanced knowledge to local conditions

• Constrains of Technology, Finance, Governance, Society

• Prioritize (many) projects (temporal and spatial scale)

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

2. PROBLEMS

Where to START with?

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

Future?

• Urbanization– hazard, exposure, vulnerability

• Future

URBANIZATION

(Thy et al, 2010) (Huong & Pathirana, 2013)

Red: Urban

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

Future ?

Highly inundated areas with strongly effected by river flow

Areas with strongly effected by rainfall

Current LU 2050 LU

No CC.

50cm SLR

100cm SLR

100cm SLR +A1F1 Flow

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

2. CURRENT PLANS

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

2. PLANS a. Drainage (flood caused by rain)

Objectives:

• 2020: reduce 70% - 80%

• 2030: No flood

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

2. PLANS a. Drainage (flood caused by rain)

Measures:

• Improving current drainage/sewer (combined) system

Issues

• Not clear non-structure (softs) measures e.g. retention basin, LID though they are recommended

• Strategy is still general (lacking of measures to support strategy)

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

3. PLANS

b. Flood plans (including CC, SLR) (national level)

Objectives:

• Reduce flood, CC/SLR adaptation

• Preparing measures until 2020

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

3. PLANS

b. Flood plans (including CC, SLR) (national level)

Measures

• Focus on river flood

• Undefined soft measures

issues:

• To reach objectives

• Prioritized projects

• Budget

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

Main proposals for the resilience action plan

3. PLANS

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

4. A ROAD MAP

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

Wh

at w

e hop

e for …

Urb

an D

evel

op

men

t P

roce

ss

Needs Aspirations State

Adaptation plans Pathways to Resilience Mainstreaming

PR

oA

CC

-II

PR

oA

CC

-I

Pro

ject

-A

P

roje

ct -

B

Policy Shift

Upscaling/Twinning

4. A ROAD MAP

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

List of current strategies

Analysis of the current strategies

Output - List of proposed

strategies - List of possible

measures (+ time/who/resources)

- Available scenarios

Output - List of possible

measures of the current strategies

- Critique on current strategies/ measures

- Alternative measures/strategies

Proposing strategies for

Mainstreaming

Output - Principles - Scale (temporal, spatial) - Proposing

strategies/measures - Demonstrate selected

measures - Challenges in

implementations

4. A ROAD MAP

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

Lumped parameters (river levels) • Uncertain sea – level rise • Uncertain land subsidence • Uncertain up-stream flood • Uncertain plan (future measures)

Base Rainfall Base Rainfall + 5% Base Rainfall+ 10% Base Rainfall + 20%

Base River level A0 A1 A2 A3

Base River level + 10 cm B0 B1 B2 B3

Base River level +20 cm C0 C1 C2 C3

Base River level + 30 cm D0 D1 D2 D3

4. A ROAD MAP

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

• Dyke plans (provincial, national hydraulic plans)

• Short ,Medium and Long term solutions

(Word bank, Australian project)

4. A ROAD MAP

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

4. A ROAD MAP

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

4. A ROAD MAP

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

Measures scenarios

Measures Initial

Inundation during 2 year Return Period rain fall with dike crest at +2.05 m and no flap gates at outfalls M1

Inudation during 2 year Return Period rain fall with dike crest at +2.05 m and flap gates at outfalls M2

Inundation during 2 year Return Period rain fall with dike crest at +2.23 m and flap gates at outfalls M3

Inundation during 10 year Return Period rain fall with dike crest at +2.23 m and flap gates at outfalls M4 Inundation during 10 year Return Period rain fall with dike crest at +2.05 m, flap gates at outfalls, Short ,Medium and Long term solutions M5 Inundation during 10 year Return Period rain fall with dike crest at +2.23 m, flap gates at outfalls, Short ,Medium and Long term solutions M6 Inundation during 10 year Return Period rain fall with dike crest at +2.74 m, flap gates at outfalls and Short term solutions M7 Inundation during 10 year Return Period rain fall with dike crest at +2.74 m with out flap gates at outfalls M8

Inundation during 10 year Return Period rain fall with dike crest at +2.74 m with flap gates at outfalls M9 Inundation during 10 year Return Period rain fall with dike crest at +2.74 m, flap gates at outfalls and Short term solutions M10 Inundation during 10 year Return Period rain fall with dike crest at +2.74 m, flap gates at outfalls, Short and medium term solutions M11 Inundation during 10 year Return Period rain fall with dike crest at +2.74 m, flap gates at outfalls, Short ,Medium and Long term solutions M12

4. A ROAD MAP

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

4. SOLUTIONS

-

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

A0 A1 A2 A3 B0 B1 B2 B3 C0 C1 C2 C3 D0 D1 D2 D3

% A

rea

inu

nd

ate

d (

30

cm

)

Scenarios

M1

M2

M3

M4

M5

M6

M7

M8

M9

M10

M11

M12

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

4. SOLUTIONS

-

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

A0 A1 A2 A3 B0 B1 B2 B3 C0 C1 C2 C3 D0 D1 D2 D3

% A

rea

inu

nd

ate

d (

30

cm

)

Scenarios

M1

M2

M3

M4

M5

M6

M7

M8

M9

M10

M11

M12

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

4. SOLUTIONS

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

4. SOLUTIONS

How to implement the measures • What are the objectives? • How do we define the objectives? • The balance on “what we want” and “what we can” • ……

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

Improving drainage system

Time, river levels, rainfall

Dyke, sluice, pumping stations

Retrofitting

Green management

Retrofitting

Retention basin

Retrofitting

Dyke, sluice, pumping stations

Improving drainage system

Improving drainage system

Measures

2050 2030

4. SOLUTIONS

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

CONCLUSIONS and OUTLOOK

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

CONCLUSIONS & OUTLOOK

• Flooding and flooding related issues (e.g. water pollution,

health risk) become more and more in Can Tho city

• Current plans are very difficult to implement

• Future changes (+ uncertainty) need a robust approach

• Measures can be taken depend on clear objectives and

resources

Developing climate adaptation and green infrastructure in medium-sized cities across multiple scales

CONCLUSIONS & OUTLOOK

• Clear and reachable objectives should be defined (in

a consultative approach)

• Detail assessment on possible resources (local,

national and international)

• Systematic implementation (integrated, crossing

different spatial-temporal scales)