Greater Hyderabad: A heat island in-the-making

Now-a-days, sustainable development is a buzz word among scientists and international forums like UNO. Brundtland Commission, 1987 observed: Sustainable development is one that meets the needs of the present without compromising the ability of future generation to their own needs.

The above observation is more relevant to keep in mind as the Greater Hyderabad is projected as “world class” city by the Telangana government. However, Greater Hyderabad requires more attention from all aspects to attain that status.

In a metropolitan city, a master plan serves as a guide for public and private decision makers regarding its future physical development. It is a long-term perspective plan that lays down the space requirements for the coming 20 to 25 years.

It suggests the growth of the city for residential areas along with amenities like commercial spaces, roads that may be totally uninhabited. These plans provide a framework for preserving the city’s character, ensuring its diversity, supporting investment and promoting desired change.

To ensure the quality of sustainability, urban planning principles manage resources including people, time, money, land and infrastructure. Therefore, urban planners must give priority to sustainable development to minimise pollution, social inequality, urban heat island, etc.

The basic parameters for planning the city, today, encompass the comprehensive approach for which all significant options and impacts must be considered for the city’s growth. So, basically for setting a benchmark for sustainability it should have an environment friendly design; the city must be zero carbon, zero waste and pollution free.

The present Hyderabad Metropolitan Development Authority (HMDA) has proposed an Outer Ring Road (ORR-Growth Corridor) of 158km with 1km width Growth Corridor having multistoried buildings on either side. It is unfortunate that our urban planners failed to understand the green belt concept envisaged by Fayazuddin almost seven decades back. He proposed five hundred meters green belt on both sides of the outer ring road.

The ORR-GC is virtually a city in ring shape which can be called as a ring city surrounding Hyderabad, to trigger large scale development. The height of the high-rise buildings in ORR-GC will be ranging from six to 16 floors and above subject to minimum setbacks as per the AP Building Byelaws 2012.

Undoubtedly, we will see the ORR-GC covered by multistoried buildings soon. Because of the building mass the heat observed during the day will be released in the night leading to heat trap. The view from the ORR- over bridge at Narsingi indicates the magnitude of the future twin ring town along the ORR leading to urban heat island.

Urban heat island is the terminology that defines the increase in temperature of both the atmosphere and the lithosphere in urban areas as compared to rural areas. The intensity of the temperature is more concentrated towards the central areas of the town and gradually lowers down as you move to the outer areas in a pyramidal type of urban development.

Urban heat islands are formed as vegetations are replaced by man-made surroundings for example asphalt and concrete for roads, buildings and other structures to meet the growing population.

In a pyramidal type of development, the city centre will have multi storied buildings, (Down Town) and the surroundings will have residential low-rise buildings. If the proposed Master plan of Greater Hyderabad comes into reality after two-three decades, it will be the bowl shape having two kilometers wide high raised buildings forming a ridge of the bowl with low lying buildings in the core area and its surroundings.

This is going to generate heat island leading to environmental catastrophe. As the airflow is obstructed in multistoried buildings, pollution levels will be increased. Whereas the trend throughout the world is to have a zero-carbon city in future, we are proposing a city model that is 100 per cent carbon. Because of the heat trap, the eco system in the inner area covered by the ring city will be seriously affected.

This also increases the consumption of more energy to have comfortable living conditions by using air conditioners. In this context, the aerosol heat factor must be considered. A joint study by ISRO and NASA shows high concentration of aerosols in the upper researches of the earth’s atmosphere, about 16.5-18.5 km from the earth’s surface. Because the ORR surrounds the city, aerosols generated from vehicular emissions will flow into the region and contribute more temperature to the normal heat trap.

The government should take note of this serious concern of the Marrakesh Declaration signed at COP22 in 2016 while preparing the Integrated Master Plan for Greater Hyderabad and take action to delete the one kilometre wide Growth Corridor with high-rise RCC buildings on both sides of ORR and replace it with a Green Corridor. (The writer is senior architect based in Hyderabad)

By Buchi Reddy Avala