On May 30, a representative of Hanoi Sewerage and Sewerage Company Limited said that with the afternoon rain of May 29, the city’s drainage system was overloaded. Flooding points are found in almost all 12 districts and a part of Thanh Tri district. The level of flooding is also higher, after 6 hours since the heavy rain stopped, many places still have not stopped flooding.
Traffic is paralyzed
According to the data of Hanoi, Cau Giay district had the heaviest rain in the afternoon of May 29 with more than 170 mm, followed by Tay Ho with more than 150 mm, and Hoang Mai with 130 mm. In Ba Dinh, Thanh Xuan and Thanh Tri districts, the rainfall is more than 100 mm. Heavy rain for more than 2 hours has caused nearly 40 streets of Hanoi to be partially flooded, many roads are flooded over 50 cm deep, and traffic has been paralyzed. For example, Duong Dinh Nghe street (Cau Giay district) is a large road, flooded for 1 km, the deepest part is the section through Keangnam building, sometimes 60-70 cm flooded.
More specific information about the drainage system in the inner city, Mr. Trinh Ngoc Son, Deputy Director of Hanoi Sewerage and Sewerage Company Limited, said that by design, the system can meet the drainage capacity with a rainfall of 310 mm for 2 days. Meanwhile, many rain spots in Hanoi recently reached 180 mm in just 2 hours.
“The To Lich river basin has been invested in the drainage project in phases 1 and 2, so it can withstand a rain of 310 mm in 2 days. The rest of the basins depend greatly on the self-flowing system of the Nhue and Nhue rivers and the river basins. Cau Bay river, urban drainage and irrigation systems should inevitably have poor drainage “- Mr. Son informed.
Mr. Nguyen Huu Thanh, Deputy Head of the Weather Forecasting Department of the National Center for Hydro-Meteorological Forecasting, said that the cause of this thunderstorm was due to the influence of a compressed low trench, so on May 29, the temperature in the North Ministries and Central regions tend to increase. On the afternoon of May 29, the phenomenon of heat and rain appeared early in the provinces of Son La, Hoa Binh and the South of the Northern Delta, then moved to Hanoi area causing heavy rain.
Many roads in Hanoi city were flooded after a few hours of heavy rain Photo: HUU HUNG
Invest in underground water storage system
Responding to the press on the corridor of the National Assembly on May 30 about the heavy rain that flooded many places in Hanoi on the afternoon of May 29, Minister of Natural Resources and Environment Tran Hong Ha said the current weather has changed. abnormal change, the temperature heats up. Not only in Vietnam, but also in countries with developed infrastructure such as the US and Europe, when the heavy rain is concentrated at a time, no infrastructure can withstand it.
Talking about the causes of frequent flooding in Hanoi and Ho Chi Minh City after heavy rains, Minister Tran Hong Ha said that it is necessary to look at the entire infrastructure in urban areas. “When designing cities with different topographical characteristics, weather extremes and population size must be forecast.
Infrastructure must be built to meet those forecasts. That is, the systems of rainwater collection and drainage and wastewater treatment must be synchronous and suitable for the population size,” said Minister Tran Hong Ha.
According to Minister Tran Hong Ha, there are problems to forecast not only in the short term but also in the long term. If extreme weather occurs only once every 20, 30, or 50 years, it is necessary to calculate a response plan to help design infrastructure such as underground works, underground roads, and roads. surface…
Emphasizing that in the event of extreme weather, a system must be calculated to store water, Mr. Tran Hong Ha cited evidence in Japan that there is an underground area, called an underground tank, which holds large water and holds water for storage. Used in drought, and in heavy rain, it plays the role of storing water.
Schools, stadiums, and rice fields can also be arranged. In case it is found that it is possible to flood in critical areas, adjust the valves in the drainage system to make those places a place to store water.
“Also, maybe an entire underground system under the road is the floor, the tank is very large to store water. That’s the solution that countries do, of course it’s expensive, but it’s important to have vision and design. and synchronous infrastructure investment” – Minister Tran Hong Ha said.
About Hanoi should have a project flood resistant Like Ho Chi Minh City or not, Minister Tran Hong Ha said that Hanoi needs to strengthen forecasting first. In addition, there is a need for an overall project, which fundamentally assesses and provides historical data as well as current data on extreme weather phenomena with this amount of rain.
In addition, Hanoi needs to study carefully in smart urban design, resistant to extreme weather phenomena. As for the problem of coping, when it is flooded, pumps must be used to drain the water.
at Blogtuan.info – Source: Soha.vn – Read the original article here
