According to experts, the continuous reduction of ponds and lakes in Hanoi also causes air pollution, because the "green lungs" of the capital are getting smaller. In addition, dust from construction sites is one of the main sources of air pollution in Hanoi. Fine dust PM2.5 and PM10 from construction activities can seriously harm human health, especially respiratory and cardiovascular diseases.
According to statistics, Hanoi ranks first in the country in terms of the number of rivers and lakes, with about 122 inner-city lakes and 13 rivers flowing through. From 2015 to 2020, the area of natural urban water surface decreased by more than 203 hectares, because up to 65% of ponds and lakes were filled in, suffocated, and wiped out.
According to a report by the Center for Environment and Community Research (CECR) under the Vietnam Union of Science and Technology Associations in 2015, in the period 2010 - 2015 alone, Hanoi had 17 lakes completely filled. In the 6 inner-city districts, the number of lakes in Ba Dinh district remained the same and 2 more were added; Hoan Kiem district remained the same; Dong Da district lost 4 lakes and no more were added; Hai Ba Trung district lost 3 lakes and no more were added; Cau Giay district lost 8 lakes and 3 more were added, and Tay Ho district lost 2 lakes and 2 more were added.
In recent years, Hanoi has been developing and renovating its infrastructure, leading to widespread construction of apartments, bridges and roads, house repairs and transportation of materials and waste. Work such as excavation, demolition of old structures and transportation of materials often causes dust pollution to the surrounding environment.
To reduce emissions, improve air quality and the environment, Hanoi has recently made efforts to implement many measures such as: Deploying buses using compressed gas (CNG), electric buses, planting 500,000 trees in the period of 2021 - 2025; installing more air monitoring stations...
Hanoi aims to plant 500,000 urban trees, renovate 45 parks and flower gardens, and complete 5 new parks in the 2021-2025 period, according to the City Party Committee's Program No. 03 on urban development and beautification.
Since 2021, Hanoi has planted more than 133,000 shade trees, 100,000 ornamental trees and 550,000 lawn trees. In 2023, the newly planted forest area will reach 47 hectares, bringing the total forest area to nearly 18,600 hectares, with a forest cover rate of nearly 6%.
Hanoi currently has about 1.8 million urban trees, mainly acacia, dracontomelon, royal poinciana, cassia, purple-flowered lagerstroemia, rosewood, linden, and cypress. Despite many efforts, the urban green tree ratio remains low, currently only reaching about 2m2/person, while the minimum green target of the United Nations is 10m2/person and the target of modern cities in the world is from 20 - 25m2/person.
