These days, the highest temperature recorded in Hanoi is from 39-40 degrees. However, off-road temperatures reach more than 50, even nearly 60 degrees. This is a consequence of rapid urbanization leading to urban heat island .
The highest temperature on June 22 in Hanoi was 40.2 degrees Celsius at the Lang point, Dong Da district. However, when traveling on Lang Ha street, Mr. Hoang Van Ha took a thermometer to measure the road surface temperature up to 58.5 degrees Celsius, 18 degrees Celsius higher than the weather tent. Mr. Le Minh Quang (Cau Giay) was also startled when he measured a temperature of 57 degrees on Tran Duy Hung street on the afternoon of June 23.
The process of rapid urbanization has contributed to turning Hanoi into a 'fire diem paint' on hot days. (Photo: Nhu Y).
Hoang Phuc Lam, deputy director of the National Center for Hydrometeorological Forecasting, said that Hanoi as well as major cities in the world are affected by heat island. This is the result of the urbanization process, when many construction works spring up, causing trees and lakes to be replaced by concrete blocks, reinforced concrete, and asphalt roads. These materials absorb and generate heat far greater than natural surfaces.
Mr. Le Thanh Hai, General Secretary of Vietnam Meteorological and Hydrological Association, said that the actual outside temperature depends on many factors such as topographic conditions, wind direction, density of trees, water surface, calf rate. cardboard. Therefore, in the hottest days, the inner city became more and more like an oasis with a temperature higher than the surrounding area.
Architect Ngo Doan Duc, Vietnam Association of Architects, said that in the last 10 years, Hanoi has sprung up a series of high-rise buildings, leading to the change of local microclimate. In addition to reducing the area of trees and water surface due to the dense construction density, buildings also emit great heat due to the use of air-conditioning equipment. "The peak of hot weather, each building can have dozens, even hundreds of hot air conditioners radiate heat into the environment, making Hanoi's capital become underground ," Mr. Duc said.
The ratio of green plants per capita in Hanoi is quite low, although in recent years, the city has actively planted many green trees. As reported by the Department of Civil Engineering, from 2016 to now, the city planted more than 1.5 million trees, set goals by 2020, the proportion of green area per capita reached 10-11m 2 .
According to experts, even achieving this goal, the percentage of trees in Hanoi still very low by the weighted average rate of the urban world around 20-25m 2 / person. In some urban areas, this rate is much higher such as Singapore with an area of trees up to 30.3 m2 / person, Seoul is 41 m2 / person, Berlin (Germany) 50m2 / person, Moscow (Russia) 44m2 / person .
Mr. Duc said that Hanoi needs to increase the percentage of green area per capita by planting more trees, expanding the area of greenery, parks and water surfaces, especially in the inner city, instead of turning. the grounds were built into tall buildings. In addition, greening of construction works is required, such as green roofs, green patios, green patios, covering large heat-absorbing surfaces such as concrete and metal.
Requesting the investors of the constructions to increase the percentage of greenery on the facade of construction works, especially buildings. In addition, waterproof surfaces can be replaced with other surfaces such as lawns, gardens, hollow tiles, increasing the use of environmentally friendly electronics. 'The greening of construction works also contributes to reducing heat in the hot, hot days,' Mr. Duc said.
There are still many heat waves in July and August
The National Center for Hydrometeorological Forecasting said that, today (June 26), due to the influence of the high wind convergence causing heavy rain in the Northern mountain region, Hanoi and the midland provinces and Northern plains the sun calmed down a little bit while still maintaining the heat. The highest temperature is from 34-36 degrees C. From tomorrow (June 27), hot and hot weather returns to the North and lasts until the end of June, then tends to end around 2-3 days / 7.
In the Central region, the heat is extremely hot and especially intense, in the coming days with the highest temperature of 36-38 degrees, many places above 38 degrees C. Forecast, by early July, the heat may decline. , only localized and not too harsh. However, the meteorological agency said, there will be more heat waves appear in July and August in the North. Particularly in the Central Region (especially provinces from Nghe An to Phu Yen) in July and August, heat waves can last for about 10 days with severe intensity.