Urban Design Codes and Ordinances as Strategies for Climate Change Adaptation in Cities (Result of Multi-Criteria Analysis)

System Description and Description of Alternatives

  1. Responses to Flooding
  2. Water Conservation
  3. Reducing Urban Temperatures
  4. Prevention of Physical Development in Flood Plain
  5. Early Warning System

Growing number of examples of adaptation policy response efforts mainstreamed into urban design code for spatial infrastructure planning in urban areas are described below:

 

i.Responses to flooding:  Building reservoirs to retain floodwater, strengthening dyke systems to resist higher flood levels, and constructing emergency spillways along dykes for selective filling of flood retention basins (World Bank, 2008 cited in UNHSP, 2011, p 149.).

 

ii. Water conservation: The supply of water from local catchments based on an integrated system of reservoirs and an extensive drainage system to channel water for supply high-grade reclaimed water, and desalinated water (World Bank, 2008.UNHSP, 2011, p. 149).

 

iii. Reducing urban temperatures:‘Cool roofs’ and ‘porous pavements’ used to reduce the urban heat island. These are covered with light-coloured water sealants that reflect and radiate more heat than dark surfaces, thus reducing the need for mechanical cooling systems (Bizikova et al, 2008 cited in UNHSP, 2011, p. 149).

 

iv. Prevention of Physical Development in Flood Plains

Legislation that deter and prevent development on flood plain is required, so as to prevent loss of lives and properties when high level of precipitation occurs that inundate the flood plains, since in most urban areas in developing countries, the urban poor constitute a large chunk of urban residents and because of their abysmally low level of income they settle on marginal lands on flood plains in spontaneous, unregulated and unplanned settlements on flood plain. This can be prevented by legislations that rigidly preclude zoning physical development to these areas to prevent phenomenal loss of lives and properties.

 

 

v. Early Warning System

The sophistication and efficiency of the mechanism for the production and reporting of early warning signals of extreme weather events is a critical factor that determine the extent to which the population of city/place respond to anticipated weather events. Where this mechanism is efficient (as in the case of the most developed countries) the population that would have been affected is sensitized or evacuated and the effect of the disaster is reduced to the barest minimum as seen in the devastation caused by Hurricane Sandy in the US in 2012.

 

Without efficient early warming mechanism and evacuation, the related losses to live would be more phenomenal. Conversely, where this mechanism is in deficit or less efficient (as in the case of the most developing countries) the population of these places is faced with the weather event as seen in the example of the recent flood in the riverine states of the Delta and Bayelsa States in Southern Nigeria.

Criteria Describing Alternatives

  1. Inclusiveness of Equity
  2. Institutional Capacity
  3. Cost Effectiveness
  4. Timely Implementation
  5. Flexibility

 

Figure 1.0 Quantitative and Qualitative Information Pertinent to Alternatives

Quantitative and Qualitative Information Pertinent to Alternatives

s/n

Criteria describing the alternatives

+/-

Measuring unit

Weight

Compared Alternatives

Responses to Flooding

Water Conservation

Reducing Urban Temperatures

Prevention of Physical Development in Flood Plain

Early Warning System

1.

Inclusiveness and Equity

 

Units

0.4

8

6

8

8

9

2.

Institutional Capacity

 

Units

0.6

10

10

8

8

10

3.

Cost Effectiveness

 

Units

0.2

2

2

4

4

8

4.

Timely Implementation

 

Units

0.4

4

2

4

4

8

5.

Flexibility

 

Units

0.2

4

3

6

5

9

        0= Minimum Point, 10= Maximum Point

      

       Figure 2.0 Quantitative and Qualitative Information Pertinent to Alternatives (Result of Multi-Criteria Analysis)

Quantitative and Qualitative Information Pertinent to Alternatives

s/n

Criteria describing the alternatives

+/-

Measuring unit

Weight

Compared Alternatives

Responses to Flooding

Water Conservation

Reducing Urban Temperatures

Prevention of Physical Development in Flood Plain

Early Warning System

1.

Inclusiveness and Equity

 

Units

0.4

8

6

8

8

9

2.

Institutional Capacity

 

Units

0.6

10

10

8

8

10

3.

Cost Effectiveness

 

Units

0.2

2

2

4

4

8

4.

Timely Implementation

 

Units

0.4

4

2

4

4

8

5.

Flexibility

 

Units

0.2

4

3

6

5

9

Significance of Alternative

0.561

0.460

0.601

0.580

0.8881

Priority of Alternative

4

5

2

3

1

Utility Degree of the Alternative (%)

(56%)

(46%)

(60%)

(58%)

(88%)

       0= Minimum Point, 10= Maximum Point