Urban Green and Urban Environment in Dhaka
Qazi Azizul Mowla
Introduction:
Like any other sustainable city, Dhaka needs a huge stock of open spaces for urban services or utilities and circulation besides space needed for different public functions and recreational activities. It is know that for a healthy city we need a right balance and proportion of open and built-up spaces. Open green spaces in the city acts like its lungs besides, being used as active recreational and leisure areas for its citizens. Circulation areas also, though serving active purposes, provided some breathing space to the urbanities. Spaces provided for the utilities also serve some passive needs. We, therefore, must realize that open spaces have a direct impact on the urban environment and general physical, mental and social health of the urban dwellers. Studies show that huge amount of carbon is locked up in above-ground vegetation, equivalent to about 3.16 kg C per square meter of the city, which seems greater than current estimates. Most of this carbon pool is associated with trees planted in open spaces. What we are discussing in this article is basically urban greening at micro levels but for the sustainability of urban environment a macro level planning is equally important. Following sections discusses the problem at a macro level.
The Context of Urban Development in Dhaka:
Our developer have made the word ‘development’ synonymous with destruction of environment but it is not so. There will be need for constructions or cutting of trees for development activities but that needs to be done in a planned manner with planned replenishment of the nature to keep the biomass in a balanced state. Although there are schemes of Social Forestry in the urban areas still they could not yield satisfactory results so far in terms of biomass and productivity because the basic spirit of such efforts are not understood. The basic concept of ecosystem is that every thing is related to every thing else. There fore any fragmented approach is disdained to fail. It is believed that a comprehensive (multidisciplinary) approach is needed to tackle the crisis. We must be aware of the interrelationships of physical and biological elements of environment to create a sustainable environment. Appropriate balance of living and nonliving parts of environment need to be promoted to maintain a sustainable ecosystem, because a stable urban morphology is always alive and careful landscape planning and design has a role to play in it.
Instead of protecting the open spaces for the sake of a balanced urban environment there were insidious attempts to destroy the greenery since independence. Trees, particularly
Key issues for eco-sustainable urbanization
Transports: an integrated approach includes tram lines, restrictions on car traffic, a network of cycle and pedestrian routes, underground parking, car sharing and people-friendly street design.
Nature: a comprehensive ‘green plan’ with special attention to biodiversity, extensive use of green drainage and roofs, as well as infiltration and biological water treatment.
Green buildings: requirement for very low energy use in all buildings, healthy materials, low water use and sewage discharge, waste separation, district cooling/heating and many projects with renewable energy. Social and cultural quality: a good social mix is the most important requirement for lively and successful communities In addition to mixed use and large numbers of work places, priority is to be given to children and the elderly and to affordable housing. There should be many community and cultural facilities.
large ones, should be protected and maintained and if more trees are planted in urban areas for their carbon storage value, they must be the right kind of tree planted in the right place so that they have a long, productive life span, and when trees die they should be replaced. But we observe in our cities, many open spaces in the city were gradually encroached upon in the last decades and plants were indiscriminately destroyed. For example in 1972 there were plans to exhume the open space now called Osmany Udyan. In the late seventies there were much-publicized events of mass felling of avenue trees in the name of road development and more recently grabbing of open spaces are noticed in order to create markets and residential plots. Who gets profit from these acts and at what environmental cost?
Figure-1: Distribution of Open Spaces in Dhaka
Udyan and complete destruction of avenue trees by the timely counseling to the policy makers by the managing bodies and some conscious citizens. The Vijaya Sthambha is being constructed in the middle of Suhrawardi Udyan that is already been encroached upon by various functions like the Shishu Park, Engineers Institution, Roads and Highways office, Shishu academy and so on – these have a destructive effect on the open space unless planned sensitively considering the park like natural environment. The point is that, if the case is properly or convincingly placed to the policy makers, on most occasions they seem to listen to the people. Therefore there is a need for awareness and sensitivity among the relevant officials / people regarding environmental issues of ecosystem. Parks and open spaces and the vegetation there in are valuable assets for sustainable urbanization.
Figure-2: Ramna Park with surrounding land uses (Once the whole area was Ramna Green) Management of Urban Open Spaces
responsible for those properties-in fact they don’t defend public properties properly in the courts to serve their own interest. How can we say that the public open spaces are not being used? There are water bodies or lakes, the roads, the greenery, the public open spaces or parks on which urban dynamics depend. How can we say we are not using them? This is at least a passive recreation for those living in the urban setting. This problem needs to be addressed immediately. As a short term strategy for land pooling under hierarchy of open spaces in Dhaka’s urban area the following may be considered. Possible relocation of Dhaka Central Jail and already vacated Dhaka Airport land in the heart of the city has provided us an opportunity of the century to make up for the scarcity of open landscape - let us see how we deal with this. As a long term strategy towards that direction, prospect of relocating Dhaka Cantonment, Border Guards Bangladesh Headquarters and perhaps university campuses may be explored to release a large chunk of land in the heart of the city which otherwise creates many urban problems. Ramna area may also be cleared of some unnecessary establishments to increase the urban central green stock (Figure-2).
The Sustainability Needs:
In the developed countries, in order to create a balanced and sustainable urban environment, we find that up to about 75% of urban area is retained for open spaces. Ideally this should this be about 40-50% but in a compact or dense situation like ours recommended lower margin is about 25% of urban space. According to the western standards, about 10 acres of recreational open space per 1000 population is recommended but minimum should not be less than 1/10th of this standard. If we go by the lower margin
we see that Dhaka needs about 10-12% of urban area as recreational open space alone. Besides, significant amount of open space is also needed for circulation purpose (at present there is about 2500 miles of urban road length) that together amounts to a minimum of about 30-35% of urban area. Against an acceptable standard of about 25% urban greenery, the Park greenery or tree-covered spaces in Dhaka constitute less than 15% of the city landscape. According to recent studies, old Dhaka has only 5% and new Dhaka has about 12% open space. The Dhaka structure plan suggests that, all type including, the open space should be at least 20%. It has been reported that more than 500 acres of public land designated for some use is lying vacant in Dhaka. If vacant lands owned by private industries and institutional lands owned by railways, port-authorities, universities etc are also taken into account, these figures may swell to a much higher figure. These statistics though grave is not totally hopeless. We can even act now to save the situation.
and environment within, are very important for assemblage of people and thus keep the city’s image intact (Figure 3), Shangshad Bhaban Precinct may be seen here as an example of integrated design. In Dhanmondi, Gulshan, Banani etc though open spaces and water bodies are provided, they are not integrated well in the settlement system (Figure 4). So it is fundamentally location, environment and hierarchy of activities leading to a space that constitute appropriate orientation. Likewise, a successful civic space must be sufficiently adored with elements, which provide scale and are in harmony with the general sitting, seeing or standing habits of the people. It does not have to be a concrete element, natural elements such as plants can very well serve these purpose.
The human quality and organic order have been shattered due to the insensitivity of city developers giving rise to the aggression of noise, pollution and crime. For example, it is observed that places with less than 60 dB sound levels are more human friendly and naturally, here also the nature (green belts and open spaces) has a role to play to combat social and physical pollutions. Therefore, for our own survival and urban sustainability there is a need to protect whatever open land including the wetland or water bodies that we have at our disposal and integrate them with our city planning with appropriate urban design or landscape design strategy,
Figure-03: Shangshad Bhaban Precinct design considering open spaces and water bodies as its integral part.
Key aspects of the development on ecological basis in Malmö, Sweden (may be seen as an example):
Energy: 100% renewable energy supply (perhaps the first in the world to reach this) including wind, sun, bio fuels and geothermal power, as well as biogas from sewage and waste.
Biodiversity: special attention paid to a very green profile, with parks and landscaping features. Buildings also had to attain a level of ‘green points’, which led to numerous innovative grass roof, facade and planting solutions. Water cycles: all rainwater is infiltrated to the ground on site - independent of mains drainage - through the use of green roofs, reed beds, retaining ponds and swales.
Transports: pedestrian and cycle paths, an ecological bus net work, and a special “mobility center” with a service centre for electric and bio fuel cars and car sharing. Unfortunately, private cars have also crept into the scheme, together with basement car parks, which many find both a negative and anti-social addition.
Aesthetic quality: a strong quality control program based on key concepts of identity, variety, complexity, human scale meeting places, security and sensory experience.
Social goals for mixed community composition, services and shops have been less successful. It will take some years before the right level of urban vitality is attained.
Building design: high demands were set for reduction of wastes and water use, energy (105kwh/m2), and healthy materials. All contractors were required to be environmentally certified. Environmentally friendly solutions for appliances include energy efficient lighting and shielded electric cabling.
Urban layout is according to bioclimatic principles using sun, light and wind sheltering, as well as the introduction of variety and interest through subdivision into small plots, as opposed to the developers’ preference for large ‘plots. Nonetheless, the layout is compact and space effective.
Figure-04: Dhanmondi R/A Designed with open spaces and water-bodies but not properly integrated.
Conclusion:
In a nut shell we may say that there is still sufficient scope to rectify the wrongs with appropriate interventions or proper planning and design, but the prime need is to make the authorities and people aware regarding the value of open spaces in the city life. They have specific duties to protect and maintain the areas under their control and that they are accountable to the general public for what they have been trusted with and that they should not consider these areas as their private property and do whatever they like. With judicious planning the vegetation situation (carbon stock) may be much improved which in turn will help sustainable eco development of urban Dhaka.
Dr. Qazi Azizul Mowla, Professor, Department of Architecture, Bangladesh University of Engineering and Technology (BUET), Dhaka-1000. E-mail: qmowla@yahoo.co.uk
Dhnmondi Lake
