Hurricane No. 3 has many strange options equivalent to fast intensification, lengthy period of tremendous hurricane, no degrading in keeping with customary regulations, hurricane circulate may be strange when inflicting very heavy rain in spaces no longer within the hurricane circulate.
Hurricane No. 3 and its circulate each have anomalies.
Mr. Mai Van Khiem, Director of the Nationwide Middle for Hydro-Meteorological Forecasting, has simply reported to the Executive on forecasting, caution, and offering knowledge on storms, rain, floods, and landslides after hurricane No. 3 devastated many spaces of our nation.
In regards to the building of hurricane No. 3. On September 3, after coming into the East Sea, hurricane No. 3 moved basically within the course between West and West Northwest. On September 5, the hurricane larger in depth by way of 8 ranges in 48 hours (from stage 8 to stage 16, tremendous hurricane stage). Hurricane No. 3 maintained tremendous hurricane stage for greater than 24 hours earlier than making landfall on Hainan Island (China) and the night of September 6.
At the evening of September 6, hurricane No. 3 entered the japanese sea space of the Northern Gulf of Tonkin, the hurricane depth diminished to stage 14, gusting to stage 17. At the afternoon of September 7, hurricane No. 3 made landfall within the spaces of Quang Ninh and Hai Phong provinces with an depth of stage 10÷12, close to the middle of the hurricane stage 13÷14, gusting to stage 16-17. At 4:00 a.m. on September 8, hurricane No. 3 weakened right into a tropical melancholy within the Northwest area.
Hurricane No. 3 has many strange options. That is the most powerful hurricane previously 30 years within the East Sea; This is a hurricane that will increase in depth in no time (in 24 hours, the hurricane depth will increase by way of 8 ranges) and maintains the tremendous hurricane stage for a very long time. When it makes landfall within the East of Hainan Island (China), it nonetheless maintains the tremendous hurricane stage.
The extent of decay alongside the best way does no longer practice the standard rule: generally when passing Hainan Island (China) into the Gulf of Tonkin, storms regularly weaken temporarily, however with hurricane No. 3, the depth didn’t lower temporarily, when drawing near the coast of Quang Ninh – Hai Phong, it nonetheless maintained the depth of stage 12÷13. The time the hurricane stayed on land used to be lengthy (12 hours).
From 7:00 a.m. on September 7 to 7:00 a.m. on September 12, within the North and Thanh Hoa, there used to be heavy to very heavy rain with commonplace rainfall of 250÷450mm, in some puts over 550mm. At 83/84 measuring stations, rainfall used to be 4÷6 occasions upper than the common of a few years within the first 10 days of September. For instance: at Sa Pa station (Lao Cai), it used to be recorded at 517mm, 440% upper; Luc Yen (Yen Bai) 503mm, 461% upper; Dinh Hoa (Thai Nguyen) 545mm, 677% upper; Son Dong (Bac Giang) 386mm, 488% upper than the common of a few years in the similar length.
The circulate of hurricane No. 3 additionally brought about many abnormalities. Hurricane No. 3 moved deep inland and weakened right into a tropical melancholy within the Northwest area. On the other hand, the heaviest rain brought about by way of hurricane No. 3’s circulate used to be basically within the East of Hoang Lien Son mountain vary, even supposing it used to be no longer within the hurricane’s trail and used to be indirectly suffering from the hurricane’s winds.
Very heavy rain over a big space (together with many provinces) within the basins of Thao River, Chay River, Lo River, Gam River with prime depth (over 200 mm/day), lasting for lots of days after the hurricane dissipated; during which, there have been spaces with rainfall over 200 mm inside simply 2 hours (in Yen Bai town, evening of September 9).
Thac Ba Hydropower Plant is operated specifically
Mr. Mai Van Khiem stated that because of heavy rain, from September 8, 2024, the water stage on many rivers and streams within the North has risen all of a sudden. Particularly, the water stage on Thao River, Lo River, Thuong River, Gam River, Thai Binh River, the decrease reaches of the Purple River, Luc Nam River, Hoang Lengthy River… all exceeded alert stage 3 (BĐ3), some rivers exceeded BĐ3 by way of 3÷4m.
Particularly, the flood on Thao River in Lao Cai and Yen Bai has exceeded the historic flood height that existed for 53 years. The flood height in Yen Bai reached 35.73m (4:00 p.m. on September 10, 2024), 3.73m above BĐ3 and 1.31m above the historic flood stage in 1968.
Flooding all over because of hurricane circulate inflicting heavy rain.
Together with that, the flood on Thac Ba Hydroelectric Reservoir additionally reached a ancient stage, threatening the protection of the dam. In particular, Thac Ba Hydroelectric Reservoir used to be surveyed and designed from 1959 – 1961, hydrological information measuring the go with the flow at the moment used to be restricted, so the spillway design had a most discharge capability of most effective 3,230m3/s. In the meantime, the true most go with the flow to Thac Ba Reservoir used to be 5,620m3/s at 9:00 a.m. on September 10, exceeding the designed flood height by way of 0.01% (5,100m3/s) and some distance exceeding the utmost discharge capability by way of 74%.
In keeping with the running process, when the water stage of Thac Ba Lake reaches 59.60m, it’ll transfer to important running mode to make sure dam protection. If truth be told, from 5:00 p.m. on September 10, the water stage of Thac Ba Lake reached 59.62m and switched to important running mode, then reached its easiest stage of 59.84m at 5:00 a.m. on Sept. 11. In concept, the take a look at water stage of Thac Ba Lake is 61.0m and if the true water stage reaches this threshold, measures will have to be taken to make sure dam protection.
In Hanoi, the water stage of the Purple River additionally recorded its easiest stage in two decades. Rivers within the Purple River and Thai Binh River basins – the biggest river gadget within the North – additionally skilled floods. Flooding on a big scale with many ranges exceeding the brink may be uncommon. In keeping with statistics, 20/25 provinces and towns within the North skilled critical flooding.
The Nationwide Middle for Hydro-Meteorological Forecasting concluded that because of heavy rains, landslides, flash floods and flash floods came about in lots of localities, inflicting very heavy injury to other people and belongings of the folk and the State. Some spaces have skilled critical flash floods and landslides, equivalent to within the provinces of Cao Bang, Hoa Binh, Lao Cai, Yen Bai, Quang Ninh…
Particularly in Lang Nu Village, Phuc Khanh Commune, Bao Yen District, Lao Cai Province, there was specifically critical human injury. The primary explanation why is that the northern mountainous area has had a large number of rain previously 3 months, 40-60% upper than the common of a few years.
“In Lao Cai in August, there have been 23/31 wet days and in Yen Bai 21/31 days, which may be uncommon. In maximum spaces, the soil is saturated with water, so when there’s a very heavy rain lasting for lots of days with prime depth like lately, landslides came about in lots of puts. Lao Cai skilled flash floods and large-scale landslides, Yen Bai had smaller landslides however came about in lots of puts (in Yen Bai town by myself, there were over 1,000 landslides recorded),” stated Mr. Mai Van Khiem.
Detailed zoning of landslide possibility issues for caution
To forestall the results of storms and floods, within the coming time, the Ministry of Herbal Sources and Atmosphere proposes to prepare investigations and surveys of the flood state of affairs and places the place landslides have came about and are going on; and to delineate intimately spaces liable to landslides for caution functions.
Total evaluation and adjustment of inter-reservoir processes of reservoirs in accordance with updating, calculating, and completely and comprehensively taking into consideration strange and emergency eventualities, local weather alternate eventualities, and so forth. When prerequisites are met, modify the Operational Procedure in a real-time course.
Analysis and suggest a plan to make use of a portion of the flood prevention capability above the standard water stage of enormous and vital reservoirs to toughen the power to chop and scale back floods downstream when emergency and strange eventualities happen (stipulated in Clause 8, Article 50 of the Regulation on Water Sources 2023).
Northern climate within the coming days, mavens say there’s recently hurricane Bebinca lively within the Northwest Pacific, forecast to make landfall within the Jap area of China, no longer affecting Vietnam.
Within the East Sea, there’s recently a tropical convergence zone (low drive trough) mixed with robust southwest monsoon winds that can reason rain within the Central Highlands and the South till September 26, with reasonable rainfall of 40÷80mm, concentrated within the afternoon and at evening. This kind of rain is not going to have a significant affect at the North.
The elements forecast for the North within the subsequent 7 days is basically little rain, with intermittent sunny days. Specifically from the evening of September 15 to September 17, 2024, the North, that specialize in the provinces of Lao Cai, Yen Bai, Phu Tho, Quang Ninh and Hai Phong, can have average rain, with commonplace rainfall of 10÷30mm/day, with some spaces having heavy rain over 50mm/day.