The middle and lower reaches of the Yangtze River are prone to flood disasters. Briefly describe their causes and control measures.

The reasons why floods are prone to occur in the middle and lower reaches of the Yangtze River:

1. Climatic factors: Affected by factors such as subtropical monsoons and typhoons, precipitation is heavy and concentrated, with heavy rains in summer.

2. Topographic factors: The rainstorm confluence area is large, there are many tributaries, the terrain is flat, the river is curved, the drainage is poor, and it is sandwiched between the north and south hills and mountains.

3. Human factors:

1) Upstream vegetation is severely damaged, water and soil are lost, sediment is accumulated downstream, and the river bed is raised, affecting flood discharge.

2) The lake area is reduced to create farmland, and the lake's flood storage capacity is weakened.

Control measures:

1. Strengthening embankment construction, river regulation and reservoir engineering construction are direct measures to avoid flood disasters.

2. Long-term and sustained implementation of soil and water conservation can fundamentally reduce the chance of flooding.

3. Effective scientific forecasting of floods and weather and reasonable planning of flood detention areas can reduce the losses caused by flood disasters.

4. Establishing an emergency response system for flood prevention and rescue operations is the final measure to reduce disaster losses.

Extended information

The formation process of the middle and lower reaches of the Yangtze River:

The middle and lower reaches of the Yangtze River plain is located in the Yangtze quasi-platform fold and fault zone. The Yanshan Movement produced a series of The rift basin was later cut through, connected and alluvial by the Yangtze River, forming the entire middle and lower reaches of the Yangtze River plain today.

Affected by the neotectonic movement, the Cretaceous-Tertiary red layer and Quaternary red soil layer on the edge of the plain were slightly lifted up. After being cut by flowing water, they became laterite hills with a relative height of 20 to 30 meters. The central and coastal areas along the river continue to decline to form flood plains and coastal plains.

Distribution of floods in China:

The main flood areas in China are located east of the Greater Hinggan Mountains-Taihang Mountains-Wuling Mountains.

According to historical rainfall statistics, the areas with the most severe rainfall are mainly the southeastern coastal areas, the Hunan-Jiangxi region, and the Huaihe River Basin. The areas with less severe rainfall include the middle and lower reaches of the Yangtze River, Nanling, Wuyi Mountains, and the Haihe River. and the lower reaches of the Yellow River, Sichuan Basin, Liaohe River, and Songhua River areas. The regions with the least rain and waterlogging in the country are the northwest, Inner Mongolia and the Qinghai-Tibet Plateau, followed by the Loess Plateau, the Yunnan-Guizhou Plateau and the northeastern region.

In summary, the general characteristics of the distribution of rain and waterlogging are: more in the east and less in the west; more along the coast and less in the interior; more plains and lakes, less plateaus and mountains; more east and south slopes of mountains than west and north slopes. few.

Baidu Encyclopedia - Plains of the Middle and Lower Yangtze River

Baidu Encyclopedia - Floods