Brazil's Acre state has entered a state of emergency. How serious is the local flood?

In the past few days, the cities of Acre State 10 in northwest Brazil have been flooded, and the lives of about130,000 people in the whole state have been seriously affected. Displaced people are placed in temporary shelters set up in schools, gymnasiums and other places. At present, Acre state has entered a state of emergency on 16 due to the worsening epidemic situation in COVID-19, the outbreak of dengue fever, the near collapse of the medical system and a large number of Haitian refugees entering Brazil from the border between the state and Peru. ?

△ Alec suffered from floods (Source: Brazil Global Media Group)

On February 20, local time, local doctor Rodrigo? A photo of a baby with pneumonia taken by Damascus in a rescue boat on a flooded street has been widely circulated on local social media platforms. Tarauca is one of the cities most affected by floods, and more than 90% of the urban areas are flooded. The head of the civil defense department in Tarauca said that the flood has caused more than 400 people to be homeless and the lives of about 28,000 people have been affected. ?

△ The doctor saw the baby on the street flooded by the river (Source: photographer Lucas? Melo's social media platform)

Flood disaster is one of the most serious natural disasters in the world. Floods are often distributed in places with dense population, high degree of agricultural reclamation, concentrated rivers and lakes and abundant rainfall, such as the warm temperate zone and subtropical zone in the northern hemisphere. China and Bengal are the countries with the most frequent floods in the world, and the floods in the United States, Japan, India and Europe are also very serious.

China, with its vast territory, complex terrain and remarkable monsoon climate, is one of the countries with frequent floods and wide influence. About 35% of cultivated land, 40% of population and 70% of industrial and agricultural production in China are often threatened by river floods, and the property losses caused by flood disasters rank first among all kinds of disasters. According to historical statistics, during the period of 2 155 years from 206 BC to 2 1949 BC, there were 1092 major floods in China, with an average of every two years. 1954 is the worst year of flood disaster in the whole Yangtze river basin since 1949. The affected area of crops in China reached 2.4 billion mu, and about 330,000 people died.

For example, in 1998, the Yangtze River, Nenjiang River and Songhua River basins were flooded, with an affected area of 33.4 billion mu, affected population/kloc-0.8 billion people (times) and 4 150 people died.

From the mechanism of flood disaster, flood disaster has obvious seasonality, regionality and repeatability.

Floods in most countries in the world are prone to occur in the second half of the year, and floods in China mainly occur in 4? September.

For example, almost all the floods in the middle and lower reaches of the Yangtze River in China occur in summer. Flood disaster is related to the temporal and spatial distribution of precipitation and topography. The areas with serious flood disasters in the world are mostly on both sides of rivers and coastal areas.

For China, floods are generally more in the east and less in the west; There are many coastal areas and few inland areas; There are many plains and few plateau mountains. Flood disasters, like climate change, have their own changing rules, which are composed of various long and short periods, making flood disasters happen repeatedly.