See the Hungarians working on the rivers, the Dutch construction dams against floods

Starting from the heart of the central region fighting the wrath of Thuy Tinh, an expert from the Netherlands sent to Vietnam Week to analyze the flood coping experiences of the two European countries.

Addressing the root of the flood problem

Many people are angry that the main cause is the construction of small hydroelectric plants on short stretches of rivers and the destruction of riparian forests.

I think it is necessary to analyze calmly and give solutions and recommendations to the Government to solve the problem of future floods because other countries have also done it. For example, Hungary rectifies the river Tisza or Holland, which is below sea level, but is not flooded or seasick yet, although it is also affected by climate change like our country.

The historical level of the water level was higher than the flood peak of 1979, causing thousands of houses in Quang Binh to flood heavily

Flooding is the cause of much water accumulating in an area and less water seeping into the ground. If you want to avoid it, you must prevent the water from entering or draining the water and not resist, you must stay away from flooded areas.

In addition, it is necessary to have an accurate forecast of the weather and the amount of water that will flow downstream to prepare for timely prevention, to minimize the loss of life and property. For thousands of years, the descendants of Son Tinh have built dikes in the north and a canal system to guide the water in the southern delta and achieve proud results.

First of all, let’s talk about the rain in us, on average between 1500 mm and 2000 mm, 3 times more than in Hungary or the Netherlands, and in recent days there are places up to 3000 mm. This means that the amount of water in the sky is much higher and when it rains, the water will follow the slopes and hills to the lowlands, causing flooding.

If the slopes of mountains or slopes are covered with trees, the water will be blocked and the soil will absorb a considerable amount, which can contain up to 90% of the rain.

So when building a hydroelectric plant or industrial area, a large area of ​​forest along rivers and streams was destroyed and the people who lived there had to move higher and the deforested area was urgent. double. Some people think that the main objective of deforestation is because the capacity of several MW of electricity is not much. So people vent their anger on hydroelectric plants is partially founded.

Move people to higher areas, build houses to avoid flooding permanently

According to the statistics of the Vietnam Forestry Administration, MARD, just over 5 years (2012-2017), the natural forest area lost due to the change of purpose of forest use in the approved projects represents 89% of the total reduced forest area . ; The rest is due to illegal deforestation, resulting in a loss of 11%.

From the synthesis of 58 provinces and cities throughout the country, it can be seen that in the last 5 years, state agencies have approved the change in forest use for about 38,300 ha / 1,892 projects. Notably, some severe cases of deforestation in the central highland provinces, Quang Nam, Quang Ngai, Binh Dinh, Nghe An, Bac Kan and Dien Bien were slowly detected.

Nghe An Department of Science and Technology Produces Electric Activated Salt Water to Help Flooded People

According to the Ministry of Agriculture and Rural Development, the management is not resolved, inconsistent, there are even indications of avoiding responsibilities, ignoring, helping people deforest, causing great damage to forest resources, generating frustration in society. In some newspapers, the photos show the meter-thick wooden tables found in families or agencies of the forest protection and management authorities. And today the central provinces are suffering in part for the aforementioned reason.

My friend from Le Thuy, Quang Binh, said that as a child, he had to take turns watching the water overflow. This year it is more than 60 years old and the flood is the same and even more. Do people stick to the floodplain all the way or is there a problem with city planning or rural development?

Why is it not possible to move the population to higher ground as the Romans did more than 2,000 years ago, choosing the high hills to build new cities? Or at least build some permanent flood proof houses and equip some local rubber boats or develop an IoT system to notify the return of water?

Also, most of the rural areas are concreted, like Hanoi Old Quarter, no pond full of water, and the brick road as before. When it was concreted, the rainwater could not seep to the ground, it overflowed, and the pond filled up, causing flooding when it rained a little but was not there before.

In the Netherlands, sidewalks and sidewalks in towns or cities are tiled with a layer of sand of about 35-40 cm, thus absorbing a considerable amount of water and there are many lovely lakes and canals. .

Hungary straightens the river Tisza

In the next part, we should discuss how to make the water flow quickly to the reservoir or the sea because when looking at the map, our rivers and streams are winding, very poetic, but the flowing water will not be able to overflow quickly. edge.

Sông Tisza, Hungary

The uneven river was also the cause of annual floods in Hungary until the Tisza river was rectified to straighten the flow. If you look closely at the stream images uploaded to the internet, you can see that streams, crevices, and bumps have not been naturally dredged, especially estuaries. The layout of the Hungarian lessons is also very interesting.

Holland has dikes around the river and the coast

The embankment part does not allow water to enter the residential area if you cannot move them to high places. The Netherlands has a third of the area below sea level, which was hit by the historic flood of February 1953, about 20% of the area was more than 1 meter underwater and the tide hit, causing great damage to life and property. .

The only automatic breakwater in the world: Maeslantkering in the Netherlands

They have successfully built levees around rivers and coasts and have established systems to pump rainwater out of residential areas when needed. And from 1953 until now, only small flooded areas will occur if the rain is very heavy. Knowledge of embankments and irrigation is nothing new. Although there are many students trained in water management in the Netherlands, it seems that the knowledge has not yet been used.

Accurate flood forecast

The bottom line is an accurate flood and weather forecast that is critical to timely preventive action, complex science based on data collected over many years, and a combination of science. various such as hydrometeorology, measurement, soils …

Weather forecasting is often based on a modern mathematical NWP (numerical weather forecast) model to interpolate temperature, storm or wind based on collected data such as humidity, wind, pressure and temperature. various locations through monitoring equipment, radar and satellite images.

Dutch weather photo at 3:45 am

In the Netherlands, before leaving home, people have a habit of watching the forecast program on their smartphones to see if it rains to bring umbrellas. I was amazed at the accurate results every hour.

Weather related data such as humidity, temperature, precipitation, pressure, location, weather … need to be stored in a big data system – big data, but our weather forecast center is still Por Therefore, detailed data is not collected for many years and the Machine Learning method can be used to predict accurately, helping us to respond quickly to the time change. details.

The weather forecast center must adopt new digital technologies such as the development of an accurate weather forecast application on the Cloud Computing platform for everyone.

As for forecasting when and which floods will return, digital maps of rivers, forests, soil types, soil water permeability, rainfall, waterways, catchment areas are required. Digital Terrain Model (DTM). DTM is a mathematical model based on known coordinates (X, Y, Z) to interpolate unknown points.

Construction of a modern hydrometeorological data center

In the 1980s, research on DTM algorithms (and it was DTM that brought me into the world of information technology) had a great need for the military to simulate and control cruise missiles or drones.

In construction, it can be used to design three-dimensional, optimize the leveling of soil and rocks, calculate the extraction volume, construct and design sewage and storm water pipes, optimize the location of transceiver stations. in telecommunications (BTS) or radar stations …

In calculating the flood, it can be simulated that when the water rises, for example, 3 m, the area will be submerged under water, it is necessary to evacuate. In Hungary, all knowledge about irrigation, measurement, construction, water management … is taught at the Budapest Polytechnic, but in Vietnam there are different universities and ministries dispersed. It is very difficult to work together to have a specific solution in the near future.

The Vietnam Department of Geodesy, Maps and Geographic Information should make high altitude digital maps and digital topographic maps with the necessary information layers, updated data, scale from 1: 10,000 to 1: 2000, for the purpose of forecasting the overflows of flood water at certain times as discussed above.

Accurate digital mapping and construction of a modern hydrometeorological data center should be seen as an important task in MONRE’s National Digital Transformation Program.

Each person must plant some trees.

Some little ideas like compressing incense, praying for the transcendence of the victims, and sharing the loss and grief of families in Central Vietnam. Hopefully the authorities will listen and take strict measures to avoid deforestation, without sacrificing development at all costs, using solar, wind and tidal energy instead of small hydroelectric plants. and swimming lessons should be compulsory in schools in flood-prone areas.

Workshops should be held with all relevant scientists and authorities for a viable future flood protection strategy. What needs to be done right after the flood is for everyone to plant as many trees on the land as they can. I believe that the descendants of Son Tinh will defeat the descendants of Thuy Tinh.

Lam Viet Tung (IT – Telecommunications Consultant for Vodafone Ziggo)