India is vulnerable to a wide range of natural disasters, including heat waves, droughts, floods and cyclones, due to her geo-climatic conditions. The loss due to such disasters in terms of life and property is high. While the country has been able to reduce the loss of life due to disasters significantly over the years, there is always scope to do more, including through construction of climate-resilient buildings.
While the government of the day focuses understandably on pre-disaster, disaster and post-disaster management, there is a strong case for communities at risk to make informed decisions during construction of buildings. Since constructions in developing countries are usually self-built, the United Nations Environment Programme (UNEP) has recently come out with A Practical Guide to Climate-resilient Buildings and Communities. The guide for common people showcases replicable good practices from around the world, mostly traditional, for constructing climate resilient buildings.
Heatwaves
Planting urban forests and creating green spaces provide shade and cooling in the neighbourhood. Heat inside buildings can be reduced by constructing green rooftops or ventilated roofs, and going in for reflective surfaces or paints. Having longer walls facing north and south and minimising east and west openings in the built-up property, too, reduce the impact of heat.
New Delhi’s Juanapur housing resettlement colony employs a cluster design to ensure shading and also create a corridor for directing the wind to offer relative cooling to dwelling units. Similarly, orientation of buildings, construction of high-rise rooms and large openings for ventilation are part of traditional design in Vietnam. In China, trombe or dark coloured sun facing walls, which are thick structures of concrete, are used for reducing the impact of external heat indoors in the daytime.
Coastal flooding and sea-level rise
Constructing buildings well above the ground level is a simple method to leave space for flood waters to flow underneath and resume life. There are examples of houses in Kerala built on pillars of treated bamboo and other construction material, leaving the surface level for flood water to flow. Similarly, buildings in coastal areas in Malaysia are sufficiently elevated to provide for water flow and growth of wetland vegetation. Though constructing elevated buildings costs more upfront, in the longer run benefits outweigh costs.
Cyclones and strong winds
If one cannot avoid cyclonic areas, constructing round-shaped houses and factoring in aerodynamic orientation to direct wind flow helps in reducing the impact of cyclones. Roof design is particularly important. Buildings with connected foundations and roofs can withstand strong winds. Similarly, roofs with multiple slopes are useful. Damage to the main building can be also reduced by covering balconies with roofs that break under the impact of strong winds, in what is called intentional planning for damage as in frangible architecture, thereby saving the main building.
Droughts
Rainwater harvesting to store water during heavy rains for use during droughts and recharging groundwater are well known practices. Planting drought resistant trees and vegetation around buildings too reduces the impact of flooding as well as droughts. China’s Sponge Cities Project is using eco-engineering for water harvesting focused on natural accumulation, natural infiltration and natural purification to address water resources shortage.
Of course, these are only indicative examples. India abounds in deploying such traditional practices as well as other modern technologies. It is time to not only showcase such replication worthy practices, but also promote them so that at-risk communities use practices suitable in their context.
The apex national and global institutions are already in place. In India, the National Disaster Management Authority (NDMA) has already taken upon itself to promote community-based disaster management and best practices in the country. Similarly, the Coalition for Disaster Resilient Infrastructure (CDRI) hosted by India, too, has a global mandate to build capacity of local communities to enhance their disaster resilience. Promotion and successful implementation of such practices will also contribute to the achievement of the ninth Sustainable Development Goal (SDG) on building resilient infrastructure for a better world.
Source: The Times of India
Published on 14 July 2021