Delhi's plan to mitigate heat impact: No schools in afternoon

Delhi will alter school timings, suspend non-essential water use, provide uninterrupted power supply to health facilities and survey vulnerable locations daily to mitigate the impact of extreme heat on susceptible populations in peak summers, according to the city's new heat action plan. The Delhi Disaster Management Authority (DDMA), which prepared the plan and submitted it to the Centre last month, also plans a pilot project to paint roofs in identified areas with white colour to help keep the indoors cooler.

The nodal officer, who will be responsible for the implementation of the heat action plan (HAP), is still to be appointed, a DDMA official told PTI.

Delhi is one of the hottest cities in India and ranks among the most susceptible to heat waves due to its large population and a significant concentration of lower-income groups.

India reported 706 heatwave incidents from 1971-2019 which claimed more than 17,000 lives, according to a paper authored by M Rajeevan, former secretary of the Ministry of Earth Sciences, along with scientists Kamaljit Ray, S S Ray, R K Giri and A P Dimri.

A study by the Indian Institute of Technology-Gandhinagar says India could witness a staggering 30-fold increase in severe heat waves by 2100. A 75-fold rise is predicted under a business-as-usual scenario.

The Delhi HAP relies on heat wave forecasts from the India Meteorological Department for the next seven days for issuing colour-coded alerts to the local population.

A 'red alert' will be triggered when the maximum temperature exceeds the normal temperature by at least 6 degrees Celsius. An 'orange alert' will be issued if the maximum temperature is four to five degrees Celsius above normal, while a 'yellow alert' will be given for a departure from normal ranging from 0 to 3.9 degrees Celsius. The heat action plan will be implemented in three phases: Phase 1 (pre-heat season -- February and March) is dedicated to developing early warning systems and a communication plan for issuing alerts to the general public, healthcare professionals, and voluntary groups (caregivers). The focus is on training and capacity-building for these groups.

In Phase 2 (March to July), "cooling centres", including temples, public buildings, malls, and temporary night shelters, will be activated to offer outdoor workers, slum communities, and other vulnerable populations access to shaded areas in response to heat alerts.

Non-essential water uses will be suspended in case of water shortages. Access to potable water will be expanded to religious places, bus transit stations, and water pouches will be provided in poor and high-risk areas, the plan states.

The education department will have to ensure that "schools do not function during peak hours (12 noon to 4pm)" when a heatwave is declared.

According to official estimates, around 2 crore residents of the national capital need approximately 1,300 MGD of water for consumption and daily needs. But the Delhi Jal Board can supply only around 1,000 MGD, leaving many areas grappling with water shortage.

The Delhi HAP recommends creating water points and providing oral rehydration solution (ORS) at construction sites, bus stops, and other public places, especially during events like rallies in the summer. Water tankers will be made accessible in slum areas upon request during days with an orange or red heat alert, it says.

Uninterrupted power supply to critical facilities such as hospitals and health centres will be given priority, the night shelters will remain open throughout the day, and large LED display boards will be installed at key locations to share temperature forecasts with the general public.

The nodal officer will hold regular meetings to monitor developments during a heat alert.

Under Phase 3, which will be implemented in the July-September period, cool resting centres will be established in high-risk areas and tree plantation will be undertaken in heat hotspots.

The nodal officer will evaluate the reach and impact of the plan and revise it accordingly. The revised plan will be uploaded on the Delhi government's website ahead of the next heat season for stakeholders’ feedback and opinion.

As part of a trial project, roofs will be painted with white colour to help keep the surface cooler.

Cool roof paints reflect a significant amount of the sunlight away, preventing the roof from getting as hot as it would with regular paint.

Many cities in India, for example Ahmedabad and Hyderabad, have adopted cool roof strategies because of their simplicity and low cost. Depending on the setting, cool roofs can help reduce indoor temperatures by 2 to 5 degrees Celsius as compared to traditional roofs.

The Delhi HAP states that the cool roof programme needs to be targeted towards the most vulnerable settlements with poor-quality homes that trap heat and become dangerously hot.

"People living in slums and low-income communities are particularly vulnerable to heat. A large percentage of their homes are far from being optimal. As a future recommendation for addressing extreme heat in Delhi, households in wards that rank high on the risk score can be selected based on factors such as the household's electricity bill, having a tin roof, direct sunlight exposure, and the number of household members sharing the space," the plan reads.

The action plan also recommends distributing gunny bags, which have a natural ability to absorb heat, for use on tin roofs or asbestos in slum areas.

It calls for diligent monitoring of heat-related illnesses and fatalities at hospitals and health centres, underling that such reports provide insights into the impacts of heat, regardless of current weather conditions.