Wednesday, September 28

Planning a green city


URBAN green infrastructure is a means of spatially organising urban environments to support a suite of ecological and cultural functions (Ahern 2007).

In this apt definition of a green city, Ahern clearly distinguishes between green infrastructure and greenness.

Unfortunately, very often, we see urban planners confusing these two elements, equating green infrastructure with a green city.

Green infrastructure should be the foundation on which the complex ecological and cultural functions of an urban landscape interact with each other.

One of the widely referred models in urban landscape planning is the ABC (Abiotic, Biotic and Cultural) resource model.

The model extensively deals with the impact of human beings on the abiotic and biotic components of an urban ecosystem (Ndubisi 2002).

It also emphasises the need for considering all three components while planning an urban landscape.

In this article, I explore various possibilities by which we could strike a balance between the abiotic, biotic and cultural components — an essential requirement for any ‘Green City’.

One key factor that is indispensable for any city is the ‘green lung’ space. A green city should have enough non-built areas reserved as lung spaces.

These spaces would ideally have diverse tree species that represent the flora native to that geographical region.

Such lung spaces also come with recreational benefits as they also double as parks.

We do find green parks at random patches in most Asian cities. However, they tend to function in isolation due to the ‘fragmentation effect’.

For a healthy urban landscape, these lung spaces should be interconnected to each other through a corridor of trees and bushes. Avenue trees along road sides and waterways/bodies could easily serve as such corridors.

In addition, educational institutions such as schools and universities should also be encouraged to plant more native trees, thus doubling as green spaces.

Original vegetation on pivotal landscapes such as hills, river and stream banks, estuaries and sand dunes should also be preserved as they also serve as lung spaces, genetic stocks or natural barriers.

A study done by researchers from Universiti Malaysia Sarawak (Unimas) shows that the majority of the avenue trees in Kuching are non-native (Zainudin et al, 2012).

Of the 15,000 tree species in Borneo, how difficult would it be for us to find a few native tree species that can be planted along our beautiful roads and waterways?

Sarawak — the Land of the Hornbills — is also the land of ethnic cultural diversity.

Our native communities accord immense cultural values to various tree species that also play a significant role in the local ecosystem.

Planting such local trees will not only serve the ecosystem, but would also remind people of the rich cultural heritage of the land.

It is a wrong notion to believe that the mere planting of trees would help the urban ecosystem.

If we are really keen on improving the quality of an ecosystem, the right approach would be to plant native vegetation that also support the native avian and insect populations (Schimdt & Whelan 1999; French et al 2005).

As cities grow, it is quite natural that built environments replace natural ones. As a part of this process, native trees are cut inevitably all over the world.

At a later stage, the city is ‘reverse greened’ with tree species — mostly exotic ones as they are mysteriously easier to procure and grow. These exotic ones do not offer much service to the ecosystem other than shade, aesthetics and noise buffering.

A right approach here would be to identify the important tree species in a plot prior to its clearing and spare them from the axe while the ‘land developer’ builds housing units at a later stage.

The stakeholders should take into account the benefits that these native trees could bring in terms of premium ‘green branding’.

Clearing all the trees prior to building and planting exotic trees after the buildings have been built is more like beating around the bush.

Sarawak Forestry’s commendable policy of planting only native tree species in afforestation programmes should be noted here.

One key requirement for green branding for a city is to reduce its energy requirements.

This can be achieved by adopting simpler measures such as larger windows in housing units to permit more light and air.

An extended roof overhang will reduce the incidence of radiation falling on walls, thereby keeping the air inside cooler.

Ironically, intermediate housing units do not permit enough light and air to come in as a result of which people tend to spend more energy on air conditioning, though it undoubtedly helps in cutting down construction costs.

Creativity in designing both housing units and shop lots should be encouraged and building designs should ideally integrate the vibrant Dayak, Malay and Colonial designs.

Diversity of designs serves as an incentive to the traveller while predictable, monotonous designs can actually be a turn off for a tourist as well as the inhabitants. The same has to be borne in mind while conceiving the city.

Cities should not be seen as smaller replicas of the capital cities.  Public transport holds the key for the future.

A cost-effective, comfortable and reliable public transport network will discourage people from using private vehicles.

This in turn would bring down the level of air pollutants, besides decongesting the city. Even the worst polluting public bus is eco-friendlier than the greenest private car, considering the number of people moved per litre of fuel and the gases emitted.

As cities grow, emphasis should be given to providing dedicated lanes/corridors for public transport which could also be utilised by the fire, police and ambulance services, who otherwise risk being delayed by traffic congestion.

A robust public transport system should be augmented by metered taxis to attract tourists.

An unreliable public transport and an unmonitored taxi system is a turn-off for tourists as they hike up tour expenditure.

Dedicated cycling lanes and proper pedestrian walkways free from encroachments are also obligatory requirements for any green city.

A stress-free life is an indispensable, yet often under-recognised requirement for a green city.

A city such as Miri that is blessed with mature, smiling and easy going inhabitants, no road rage and superior law and order, would naturally rank higher in this aspect.

However, the key is to sustain this stature amidst the continuing growth and conglomeration of population and futuristic, realisable visions can go a long way in shaping a green city.

As Campbell (1996) said, “In the coming years, planners face tough decisions about where they stand on protecting the green city, promoting the economically growing city, and advocating social justice.”

Dr Merlin Franco is an ethnobiologist working with the Curtin Sarawak Research Institute (CSRI).