Warning of early El Nino causing severe heat and drought in Nghe An

Concept of EL Nino and LA Nina

Currently, not only Vietnam, but the whole world is very concerned about global warming. This phenomenon is due to the increasing climate change, causing the weather to change erratically with complex and unpredictable developments, such as: Ice melting quickly causing sea levels to rise, air temperatures suddenly increasing, torrential rains, strong storms appearing without rules... In short, in recent years, weather phenomena have appeared to be extreme and unpredictable.

With the above mentioned climate phenomena, scientists have been researching to find the causes and they pay special attention to EL Nino and La Nina.

So what are EL Nino and La Nina? In 1920, a British scientist named Gilbert was the first to discover the relationship between air pressure in the East and West Pacific, which he called the Southern Oscillation. He found that the decrease in air pressure in the East Pacific was related to drought. From there, the concept of EL Nino was born. EL Nino is the result of the interaction between the atmosphere and the ocean, which is mainly expressed in the circulation between the atmosphere and the surface water temperature in the equatorial Pacific region.

Illustration of El Nino. Photo: Internet

The occurrence of the EL Nino phenomenon represents an oscillation in the mechanism of global climate and EL Nino is called the warm phase often used in texts when talking about the weather.

La Nina is called the cold phase, which is the phenomenon of the surface sea water in the above mentioned area.abnormally coldoccurs with a similar or less frequent cycle than EL Nino.

To express the contrast between the two phenomena of EL Nino and La Nina, people use the concept of Anti - EL Nino (opposite to EL Nino). The phenomenon of La Nina can appear right after the phenomenon of EL Nino weakens.

In addition, there is also the ENSO phenomenon, which is an abbreviation of the compound words EL Nino Southern Oscillasion to indicate the relationship between the two phenomena EL Nino and La Nina.

According to the forecast of the World Meteorological Organization (WMO), the air temperature in 2023 will be the highest compared to previous years, the heat will be intense, the air humidity will be low, there will be little rain, drought will occur on a large scale, and salt water in the sea will rise deep into low-lying areas. All due toThe return of the El Nino phenomenon appears earlier than in previous years.and with quite strong intensity of extreme activities, appearing quickly, with little seasonal interference like in the past.

In the country, according to the forecast of the National Center for Hydro-Meteorological Forecasting, this summer will be hot, with air temperatures 0.5 - 1 degree Celsius higher.⁰C compared to the average of many years and came earlier, but it rained very little compared to previous years.

Risk of severe heat and drought in Nghe An

In Nghe An, on March 22, the heat was intense and the air temperature in Tuong Duong district reached 42 degrees.⁰C, Nghia Dan 41⁰C. Next, on April 18, the air temperature in the above localities rose to over 42⁰C and the most recent time was on May 6, in Xiangyang the air temperature rose to approximately 44⁰C.

According to the forecast of the Hydrometeorological Department, the coming months will be even more hot and dry, the air temperature will increase even more, there will be almost no rain, drought and salinity will be more serious.

Early season drought in Que Phong district. Photo: Van Truong

Meanwhile, the amount of water in 1,061 large and small lakes and dams in our province has decreased sharply in recent months due to lack of rain and having to serve irrigation for the spring crop.

According to data from the Nghe An Irrigation Department, by the end of March 2023, out of 102 lakes managed by irrigation enterprises, only 4 lakes were full of water, compared to 12 lakes in the same period in 2022; 56 lakes had a water capacity of 70% or more compared to the design capacity, compared to 65 lakes in the same period in 2022. The remaining lakes had insignificant water levels.

The number of lakes and dams managed by localities is 959, only 26 lakes and dams are full of water, the remaining 933 lakes have water levels at 40% or less compared to the design capacity.

Ban Ve Hydroelectric Reservoir is the largest reservoir in Nghe An province, with a design capacity of 1.8 billion m³water. But as of April 14, 2023, the current capacity is 951.32 million m³water, reaching less than 59.9% of the design capacity. If calculated by the beginning of May, the amount of water in the lakes and dams is no longer as the above data, due to the hot weather and having to release water to serve the spring rice in the flowering, milking and ripening period.

On rivers and streams, the water flow has also dried up. In particular, on Lam River, the largest and longest river in the province, dozens of electric pumping stations are being installed to get water to serve the social needs of the people, mainly agricultural production.

Not only has the water flow in rivers and streams decreased sharply, but saltwater in coastal estuaries has also risen, penetrating many kilometers inland, especially the Lam River. Clearly, the risk of severe heat, drought, and salinity is causing many difficulties not only for agricultural production but also for all social activities and human health.

Up to this point, spring crop production has been ready for harvest. The effects caused by weather are insignificant for spring crop production and are expected to be a good income crop.

For this year's summer-autumn crop, the province strives to cultivate 81,500 hectares of rice, including 58,000 hectares of summer-autumn rice and 23,500 hectares of winter-spring rice. According to scientists and experts in meteorology and agriculture, this is a crop that will face many difficulties due to severe heat, drought, and salinity. Therefore, it is necessary to proactively combat drought and synthesize solutions to minimize damage caused by drought./.