One of the more fashionable terms to have emerged over the past few years is “sustainability.” The term is being applied to all sorts of contexts that initially concentrated on the ecological and environmental, but have come to also include the social, economic, and even that of overall development. It also applies to human settlements, whether cities, towns, villages, or neighborhoods.
A suitable point of departure for discussing sustainability is defining it. A major challenge of dealing with trendy terms is that they assume highly elastic meanings and can stand for different things to different people. This makes the attempt at identifying a single correct meaning for the term counterproductive. Instead, it would be more useful for each of those using it to provide their own understanding of it.
This article presents the term sustainable to refer to that which is capable of remaining in existence, and doing so without depleting resources. Within the context of human settlements, sustainability accordingly refers to those settlements that are capable of remaining in existence using resources - whether natural, financial, or human - as efficiently as possible. I would add that such settlements need to achieve this in a manner that makes them places that people would want to - rather than have to - live in. In many ways, the concept of the sustainable human settlement has emerged as today’s equivalent to the ideal or utopian city of the past.
Some of the qualities of the sustainable human settlement are not directly related to architecture, planning, or physical urban management. This applies to measures such the quality and quantity of available job opportunities or educational and health services, the vibrancy of cultural life, and the overall levels of human security. Other measures, however, are closely connected to the architecture, planning, and physical management of the human settlement. The following are some thoughts regarding those qualities.
The sustainable human settlement is a compact one where one does not need to cross large distances to go to work or school, buy one’s daily needs, or visit family and friends. Ideally, one should even be able to accomplish much of this on foot through ten to fifteen-minute walks each way. When distances are too large to cover on foot, a clean, efficient public transportation system consisting of buses, subway lines, or light rail, and even bicycle paths would be available. What is important is that one may easily and comfortably move around without the need for the private automobile, which is an incredibly energy-consuming and polluting mode of transportation.
A sustainable human settlement is one with an ample supply of green spaces. These include parks located inside it or - in the case of a town or city - green belts that surround it and protect its boundaries, ensuring that nearby towns and cities do not creep onto each other eating up open fields, agricultural land, or forests, thus creating large, unmanageable, and soulless urban conglomerates.
The layout of streets and land plots in such a settlement would be done in a manner to maximize southern exposures for its buildings. Here, the use of canopies or deciduous trees would allow the warm southern winter sun to enter buildings but would block out the strong harsh summer sun.
The buildings of these settlements would be well-sealed against moisture and heat leakages, and would use energy-efficient materials with high insulation capacities. They would feature solar panels on their roof tops, which could include passive panels for heating water or photovoltaic panels for generating electricity.
Water conserving plants would be used in gardens, parks, and along streets to provide greenery, absorb carbon dioxide, as well as shade building surfaces in the summer and help block the cold winter winds.
Rainwater would be harvested on both the individual building level and the wider urban level. Such water would require minimal treatment to serve various purposes including plant irrigation and general household needs.
Regarding urban management in sustainable human settlements, much of the garbage or solid waste generated would be recycled. The amounts of garbage that end up in landfills therefore would be reduced as much as possible. A variety of systems would be used for treating sewage. Gray water (water produced from sinks and bathtubs) would be separated from the sewage as it may be reused easily and safely for irrigating plants. While sewage may be treated in central plants, it also may be treated in small-scale, decentralized neighborhood-based sewage plants that only serve a few dozen households. The use of such decentralized plants eliminates the need for the sewage and the treated water to travel long distances between points of origin, treatment centers, and locations of use, thus resulting in considerable savings in the energy needed for pumping the sewage and/or treated water. In a number of cases, as in areas with low population densities or when the necessary resources are not available for large infrastructure works, these small-scale plants can be more cost-effective than large-scale ones.
The sustainable human settlement would incorporate renewable energy sources not only on the individual building level, but also on the wider neighborhood or even city levels. Streetlights would be powered by solar energy; solar farms and wind turbines would be used to generate electricity on a large scale.
The sustainable human settlement would take full advantage of advanced telecommunication technologies capable of transferring large amounts of data. Various daily transactions, whether renewing a municipal permit, making a purchase, or paying an electricity bill, would be carried out online from anywhere where there is a computer and an internet connection, thus allowing residents to accomplish much without having to waste time and energy moving from one location to the other, and helping relieve the congestion and pollution that results from such an unnecessary movement of people.
Industries in the sustainable human settlement would be clean ones. Measures would be taken to ensure that they do not pollute the air, water, or soil. This would be accomplished through various interventions such as legislation that strictly controls pollution, the wide-scale installation of air-pollution filters, and the onsite treatment of industrial waste.
Any human settlement with those features clearly would be a better place in which to live than one that lacks them. Very few cities or towns anywhere in the world today would qualify as fully sustainable human settlements. Considerable investment in infrastructure and dedication from all involved, whether decision-makers, officials, or residents, would be necessary to realize them. The results, however, definitely will be worth the cost and effort.
February 06, 2009