What monsoon was the flood of 98 associated with

It is related to the summer monsoon, because the winter monsoon and the summer monsoon are about the same intensity, the summer monsoon stays somewhere, and the summer monsoon is generated from the ocean, which will bring a lot of rain, so it rains a lot and becomes a flood!

I just learned this semester, trust me! Historical!

Flooding usually refers to the phenomenon of rapid increase in the amount of sea water or rapid water level in rivers and lakes caused by natural factors such as heavy rainfall, rapid melting of ice and snow, and storm surge.

In 98, there were floods in the Yangtze River basin and Songhua River basin, and the main factors for climate anomalies were:

El Niño events (i.e., unusually high water temperatures near the eastern equatorial Pacific Ocean). In May 1997, the strongest El Niño event of the century occurred, reaching its peak at the end of that year and largely ending in June 1998. The analysis of statistical data shows that in the second year of each El Niño event, there are two rainy belts in the north and south of China in summer, one is located in the Yangtze River and its southern region, and the other is located in the northern region.

This unusually strong El Niño event was one of the main reasons for the heavy rainfall in the Yangtze River basin in the summer of 1998.

There is a lot of snow on the plateau. According to the analysis of climatic laws, when there is more snow in Eurasia and the Qinghai-Tibet Plateau in winter and spring, the East Asian monsoon is generally delayed, the summer monsoon is weak, the main rain belt is located in the south, and the Yangtze River basin is rainy. In the winter of 1997, there was an abnormally high amount of snow on the Qinghai-Tibet Plateau, which was an important factor affecting the excessive rainfall in the Yangtze River and Jiangnan region in the summer of 1998.

The western Pacific subtropical high (hereinafter referred to as the subtropical high) is abnormal. The subtropical high is an important factor affecting the location and intensity of rainfall belts in China. In June and August 1998, the subtropical high was unusually strong, and the position of the ridge continued to maintain a southerly and westerly position, and showed a stable northeast-southwest trend.

This phenomenon has been rare in the past 40 years. In mid to late June, the position of the subtropical high was normal, and the rainfall belt was mainly located in the middle and lower reaches of the Yangtze River. From the end of June to the beginning of July, the subtropical high briefly lifted northward; Since mid-July, the subtropical high has unusually retreated to the south, and its position has been abnormally southerly and westerly, and has continued to stabilize for more than a month, so that the upper and middle reaches of the Yangtze River have been at the intersection of southwest airflow and cold air, and heavy rains have occurred frequently, resulting in flood peaks in the upper and middle reaches of the Yangtze River, and the water level of rivers and lakes in the middle and lower reaches of the Yangtze River has been rising.

The mid-latitude circulation in Asia is anomalous, and the blocking high pressure activity is frequent. In June and August 1998, the blocking high pressure situation occurred many times in the middle and high latitudes of Asia, the Ural Mountains, the west side of Lake Baikal and the Sea of Okhotsk, especially the blocking high pressure in the Sea of Okhotsk was stable and less active, and the meridional circulation of the Asian westerly wind belt was absolutely dominant, prompting the cold air from Siberia to frequently move south to affect China, which is the continuous rainy cold air conditions in the Yangtze River Basin.

Monsoons occur every year, but not every year.

During the flood of '98, Jiujiang City, Jiangxi Province, was the hardest-hit city. On August 7, 1998, Jiujiang in Jiangxi Province suddenly burst its embankment, and in a few hours, the flood submerged Jiujiang City in the westward journey and urban area, and now there is a flood fighting monument on the bank of the Yangtze River on Xunyang West Road in Jiujiang City. Regarding the specifics of "which city was the most serious in the flood in 98", if you are interested, you can continue to read and understand.

The annual floods mainly occur in the Yangtze River, Nenjiang River, Songhua River and other river basins, and the four provinces of Jiangxi, Hunan, Hubei and Heilongjiang are the most severely affected.

2. In addition to the above four provinces, 29 provinces and autonomous regions across the country have suffered floods of varying degrees, and this flood is another major flood in the national basin since 1954.

The annual floods are mainly caused by abnormal climate, excessive heavy rainfall, and the decline of the storage capacity of rivers and lakes, and they involve a wide range and last for a long time.

4. In addition to floods, long-term heavy rains have also directly led to the occurrence of disasters such as mudslides and landslides, which have increased the severity of disasters.

<> the water level rose due to the heavy rainfall during the long Hongmo period, and the tide level of the river exceeded the warning level in many places, and the drainage system at that time was not perfect, and the water of many rivers was converging together, and the drainage capacity of the river itself could not drain the river water, which led to the occurrence of floods.

The 1998 flood in the Yangtze River was mainly caused by abnormal climate, excessive heavy rainfall, reduced storage capacity of rivers and lakes, reduced peak shaving, and high water level.

In 1998, the flood level in the middle and lower reaches of the Yangtze River greatly exceeded the measured water level in 1954, and the main reasons for the formation of high flood levels were:

In 1998, compared with 1954, the total amount of flood storage in the middle and lower reaches of the Yangtze River reached 102.3 billion cubic meters, compared with only 10 billion cubic meters in 1998.

Since the founding of the People's Republic of China, the area of lakes in the middle and lower reaches of the Yangtze River has decreased by about 10,000 square kilometers, and the volume of Dongting Lake and Poyang Lake has decreased by more than 18 billion cubic meters due to siltation and reclamation.

The catastrophic flood of 1998 occurred in the Yangtze River, Nenjiang River and Songhua River.

and other major floods in river basin areas.

The '98 flood was one of the largest basin-wide floods in the 20th century, following the 1931 and 1954 floods. The floods of the Nenjiang and Songhua rivers were also the worst floods in the whole basin in 150 years. According to preliminary statistics, a total of 29 provinces (autonomous regions and municipalities) across the country, including Jiangxi, Hunan, Hubei, and Heilongjiang, which were the hardest hit, were hit by floods of varying degrees.

The affected area is 100 million mu, the disaster area is 100 million mu, the affected population is 100 million, 4,150 people died, 6.85 million houses collapsed, and direct economic losses.

reached 166 billion yuan.

The flooding of the Yangtze River is the Yangtze River basin.

Soil erosion caused by indiscriminate deforestation, and the direct consequences of the middle and lower reaches of the lake enclosing land and occupying rivers indiscriminately. There are 400 million people living on both sides of the Yangtze River, and in the mid-50s, the upper reaches of the Yangtze River were covered by forests.

22 per cent, 80 per cent of the deforestation on both sides of the river has been deforested due to ongoing land reclamation, factory construction and urbanization. Of the 193 counties in Sichuan Province, only 12 have more than 30% forest cover, and some counties have less than 3% forest cover. To this end, the Yangtze River basin is 1.8 million square kilometers.

Soil erosion occurs in 20% of the land, 2.4 billion tons of topsoil is lost every year, and more than 500 million tons of soil and sand carried from the upstream every year flows down the Yangtze River into the East China Sea. Due to the accumulation of soil and sand year after year, the riverbed of the Yangtze River has been raised above the ground since many years ago, becoming another "hanging river" after the Yellow River. The "clear water" of the Yangtze River has long been gone, and its "muddy yellow" degree can be "comparable" with the Yellow River.

On the other hand, the lakes in the middle and lower reaches of the Yangtze River that have flood storage functions are shrinking rapidly, and the water area of Dongting Lake has shrunk from 4,350 square kilometers in 1949 to 2,145 square kilometers.

Shrunk by 1 5 in 40 years, hundreds of small and medium-sized lakes have disappeared from the map forever. All this is the reason for the flooding of the Yangtze River.

The major floods in 1998 mainly occurred in the Yangtze River, Nenjiang River and Songhua River basins.

The 1998 flood was one of the largest basin-wide floods in the 20th century, following the 1931 and 1954 floods. The floods of the Nenjiang and Songhua rivers were also the worst floods in the whole basin in 150 years.

According to preliminary statistics, a total of 29 provinces (autonomous regions and municipalities) across the country, including Jiangxi, Hunan, Hubei, and Heilongjiang, which were the most severely affected, suffered floods of varying degrees, with an area of 100 million mu and a disaster area of 100 million mu, a population of 100 million people, 4,150 deaths, 6.85 million collapsed houses, and direct economic losses of 166 billion yuan.

The floods of 1998 included the Yangtze River, Nenjiang River, Songhua River, etc.

The Yangtze River flood was one of the largest basin-wide floods in the 20th century, following the two floods of 1931 and 1954. The floods of the Nenjiang and Songhua rivers were also the worst floods in the whole basin in 150 years.

According to preliminary statistics, a total of 29 provinces (autonomous regions and municipalities) across the country, including Jiangxi, Hunan, Hubei, and Heilongjiang provinces, which were the most severely affected, suffered floods of varying degrees, with an area of 100 million mu and 100 million mu of disaster, 100 million people affected, 4,150 deaths, 6.85 million houses collapsed, and direct economic losses amounting to 166 billion yuan.