Green cover shrinks as urbanisation takes toll on Bengaluru

 India's Silicon Valley-Bengaluru is fast losing its green cover with urbanisation having risen by 125 per cent between 2000 and 2014, researchers at Indian Institute of Science (IISc) claimed.

Rapidly urbanising at a pace of 4.6 per cent, Greater Bengaluru has witnessed a decline of vegetation and water bodies by 62 and 85 per cent respectively in this period.

The study was carried out using remote sensing data through Landsat satellites to explore spatial patterns of land use changes and have found interesting and alarming patterns.

The IISc team studied data of Greater Bengaluru from 1999 to 2014 and used software to analyse the land use patterns and understand the change in urban cover.

The land use classification was algorithmically computed and categorised as urban (buildings, roads and paved surfaces), vegetation (parks, botanical gardens and grass lands such as golf course), water bodies (lakes, sewage treatment tanks) and others (play grounds, quarry regions and barren land).

The study found that during this time, urban land use – for buildings, roads, - had increased by 184 per cent, while vegetation had decreased from 45 per cent to a mere 8.4 per cent. The water bodies also diminished to a mere 0.74 per cent – a drastic reduction of 85 per cent.

"The results also show a tendency of dispersed growth in all directions. This phenomenon is most prominent in North West and South West directions," the research stated.

This work, titled 'Spatial Patterns of Urban Growth with Globalisation in India's Silicon Valley', was published in the Proceedings of National Conference on Open Source GIS: Opportunities and Challenges, and was awarded the best paper award.

"Bengaluru has become a land of opportunities and growing ideas for various job markets. There has been an extreme growth in the industrial sector (IT sector) in last couple of years and migration of people to these places for housing and work has brought severe pressure on the environment.

"Further, we lack efficient transportation and thus we see people craving to stay close to their workplace adding to dependency on private vehicles," said Aithal, a post-doctoral research scholar at the Centre for Sustainable Technologies, (IISc), one of the members of the team, which carried out the research.

The study found that due to these factors the outskirts of the city towards northeast and southeast show numerous urban patches and irregular shapes.

"Our study aimed to bring out the lacunae in our planning system and to help policy makers in understanding the entire landscape. It also benefits citizens of the city to voice their opinions and obtain basic amenities as promised under our constitution. It also forms a basis to provide solutions to their elected representatives," Aithal said.

"We have modeled the urban revolution of Bengaluru with various models. The study clearly indicates that this rate of unprecedented urbanisation would create more troubles for citizens of the city, if we don't start planning a futuristic city," he added.

Aithal noted that urban India is expected to house 60 per cent of India's population (about 5 billion) by 2030 and that the number of metropolis cities had increased to 49 in 2011.

"Urbanisation being a complex product of population explosion and one major factor being poverty induced rural to urban migration. This has led to the dispersed haphazard development in the city outskirts or the periphery, which is a result of unplanned urbanisation, referred to as 'urban sprawl'.

"These areas are devoid of basic amenities and also cause fragmentation of land into smaller chunks that alter the ecosystem pattern. Greater Bengaluru, being a metropolitan city, is experiencing unprecedented urban growth of 4.6 per cent per annum in recent times," he said.