DATA

Chennai’s unregulated urbanisation has destroyed its water bodies and disrupted its natural drainage systems. This is true for the Kodungaiyur Canal System in North Chennai which includes the Ambattur, Korattur and Retteri lakes. This crucial waterway is designed to drain floodwaters into the Ennore Creek but is marred by encroachments and illegal sewage discharge. In fact, Kodungaiyur Lake, a part of Kosasthalaiyar and Cooum basin, is one of the lakes that has been eaten up and has been reduced to narrow canals because of human activity and government negligence. Flooding in encroached area, vulnerable groups affected During a datajam organised…

When the northeast monsoon hits Chennai, a foreseeable result of the heavy downpour is severe flooding in several areas, including Porur Lake. As residents living near this 200-acre water body battle inundation every year, our team set out to investigate the root causes of flooding using available data. Environmental issues have often been dealt with a one-size-fits-all approach, but our study aimed to provide specific solutions tailored to the Porur catchment area. For this, we mapped inundation patterns, land gradient, land use change and the outlay of stormwater drains (SWDs).   At a recent datajam organised by the Oorvani Foundation…

Mumbai’s L Ward, covering Kurla, Chandivali, Saki Naka, and Powai, has been quietly heating up, and not just metaphorically. It is a ward of extremes: dense slums on one side, luxury high-rises and malls on the other. But when the mercury rises, the contrasts fade, and everyone feels the burn. With urban heat on the rise across the city, L Ward is emerging as one of Mumbai’s hotspots where everyday life is increasingly being shaped by climate stress. The heat problem Spread across 15.6 sq km, L Ward is home to more than nine lakh people, packed into one of…

The Cooum River, once a sacred river that shaped the history of Madras, has now become a sad sign of urban degradation. For the millions of residents in Chennai, it has transformed into a malodorous, polluted, and stagnant channel, burdened with solid waste accumulation and extensive encroachments along its banks. During a recent datajam organised by Oorvani Foundation and OpenCity, we used Geographical Information System (GIS) datasets and population analytics to investigate the underlying causes contributing to this crisis. The results show that rapid urbanisation, inadequate provision of essential civic infrastructure, and the absence of coherent policy frameworks, along with…

Mumbai's P/North Ward is a climate paradox. On a map, it looks green, boasting significant cover from the Sanjay Gandhi National Park to the east and vital mangroves to the west. Yet, the reality on the ground for its nearly one million residents is one of scorching heat. The surfaces people walk and live on have heated dramatically, with land surface temperatures soaring by over 5°C in much of this ward between 2015 and 2024. The reason is a familiar story of urban expansion: rapid, unplanned growth has replaced cooling ecosystems with a dense fabric of concrete, tin, and asphalt,…

Mumbai's M/East Ward, a sprawling peripheral area including Mankhurd, Govandi, Deonar, Trombay and Chembur, embodies a tale of two cities. It is a vital economic engine, home to major industrial facilities such as the Bhabha Atomic Research Centre (BARC), Tata Power, RCF and HPCL. At the same time, it lies on the city's fringe where its unseen have been pushed over decades, from the mountains of waste at the Deonar landfill to the marginalised communities resettled in its cramped colonies. Our study on the impact of rising urban temperatures reveals just how this deep-seated inequality is baked into the very…

Urban Heat Islands (UHI) are areas within cities that experience significantly higher temperatures than their rural counterparts due to human activities, concretisation, and lack of vegetation. Bengaluru, the fifth most populous metropolis (Census of India, 2011) and one of the rapidly growing cities in India, is no exception. In the last two decades, the city has seen a rapid rise in built-up area from 37.4% to 93.3%. The pressure of urbanisation has not only affected the natural and ecological resources but is also impacting the city’s livability because of rising temperature levels. Unlike sudden disaster events like landslides or floods,…

Bengaluru’s air quality has been seriously worsening post COVID. The annual levels of PM10 saw a decline between 2018 and 2021, but has been slowly increasing since then. Government authorities say that the air quality in Bengaluru is better compared to other cities. But while the PM2.5 levels may conform to the national standards, according to a Greenpeace report it is still four to nine times higher than WHO standards. There is thus a huge need for improvement. The city, however, has used very little of the clean air funds received under the National Clean Air Programme (NCAP). Also non-utilisation…

As Bengaluru struggles with an ongoing water crisis, it reports a shortage of about 500 million litres of water every day. The significant water problem in the city is frequently blamed on insufficient rainfall, unregulated groundwater exploitation, and environmental negligence. However, it is essential to investigate water contamination, notably from sewage and industrial effluents, as a major cause of the water crisis. The focus then moves to Shivpura Lake in the Peenya Industrial Area.  Although a key industrial area, Peenya is neglected, as evidenced by its poor infrastructure and pollution issues. Shivpura Lake, in particular, is contaminated by the surrounding…

In December 2023, many parts of Chennai received record-breaking rains for two days. Though the event of cyclone occurrence was the same throughout the city, the capacity to recover from the aftermath was not the same for all. Experts say the reasons for this recovery variability could be attributed to infrastructure resilience such as sewage treatment capacity, water supply, water holding capacity of reservoirs and waterbodies encroachment. These physical parameters are intensified by the socio-economic status such as the livelihood, income levels, social status of people and assets across different parts of Chennai. Here, it is important to look at…