The main natural causes of flooding in the Yangtze River

1.The human factor.

First, soil erosion in the middle and upper reaches of the region, a large amount of sediment accumulation, resulting in the elevation of the riverbed and the reduction of the riverbed's passing capacity. The second is the destruction of accommodating capacity. During the flood season, excess floods, especially floods with excess capacity, cannot effectively accommodate the flooding hazards.

The third is the destruction of flood control capacity. It is mainly manifested in the elevation of the riverbed and the increase of obstacles in the riverbed. Generally speaking, water conservancy facilities have an obstacle effect, and the large and small bridges along the main and tributaries of the Yangtze River basically have an adverse impact on flood flow.

2.Natural factors.

Naturally, the reason for the frequent occurrence of flood disasters in the Yangtze River basin is abnormal, that is, the rainfall is particularly large, the intensity is particularly strong, and the scope is particularly extensive. Whether flood disasters occur in the Yangtze River basin depends on three factors: first, plum rain; the second is typhoon rain; The third is the warm and humid airflow from the southwest.

From the actual situation in the middle and upper reaches of the Yangtze River, it is mainly caused by the abnormal plum rain, and the typhoon storm surge in the middle and lower reaches, especially in the lower reaches of the Yangtze River, has a considerable impact on it. The southwest warm and humid airflow has a certain relationship with the plum rain, but its abnormal situation is caused by the non-plum rainy season, such as floods and mudslides in western Hubei Province.

Nature: The Yangtze River flows through the area with abundant precipitation, and all tributaries often rise at the same time during heavy rainfall; There are many meanders in the middle reaches, and the flow of water is not smooth; The middle and lower reaches are too flat; poor flood storage and discharge capacity of lakes; The weather is unusual.

Human-made: indiscriminate deforestation and destruction of vegetation in the upper and middle reaches of mountainous areas; The lake is enclosed to create fields, the river channel narrows, and the lake shrinks; water conservancy projects are in disrepair;

It is mainly affected by the monsoon and stays in the Yangtze River basin for a long time, so the flood season of many rivers occurs at the same time, and the downstream rivers and topography are also greatly affected.

Choose C, I was also stumbled by this question before, it is wrong in the word, it requires the main natural causes, 1 is human factors, not natural causes, so choose C

The reclamation of land around the lake is man-made.

In addition, there is a weakening of the activity of the subtropical high.

The section of the Jingjiang River is called the Jiuqu ileum).

The choice of the first lake for land reclamation is a human factor.

Reasons: 1. There are many plains in the middle and lower reaches, and the terrain is low and flat, which is not conducive to flooding.

2. It belongs to the monsoon climate, with a lot of precipitation and concentration, and a lot of heavy rain in summer.

3. The north and south tributaries flow into more.

4. The upstream area has serious damage to vegetation, resulting in soil erosion, and the downstream riverbed is raised, and sediment is silted up, forming an above-ground river (the Jingjiang River section is particularly prominent, known as the "Jiuqu ileum").

5. People surrounded the lake to create farmland, which reduced the area of the lake, and weakened the lake's ability to regulate and store floodwaters.

Measures: 1. Strengthen soil and water conservation work in the upper reaches and plant more trees.

2. The middle reaches of the river section are "cut off and straightened", and the river channel is dredged.

3. Downstream construction of water conservancy projects (reinforcement of flood control embankments, construction of reservoirs) 4. Improve people's awareness of flood prevention and self-rescue ability.

1.Precipitation is concentrated in summer. The middle and lower reaches are low-lying and flat.

2.The basin area is wide and the catchment area is large, especially in the year when the summer monsoon is abnormal, the north and south branches of the river flow enter the flood season at the same time, and the flow increases dramatically.

3.Vegetation was destroyed, steep slopes were cleared, and lakes were enclosed to create fields. Soil erosion is serious, the water level is rising, and the flood storage capacity of lakes is reduced.

Numerous tributaries 2Abundant precipitation 3The flat terrain of the plains is not conducive to the drainage of floods 4

The disappearance of the lake leads to a weak water storage capacity 5Sediment accumulation, resulting in a raised riverbed.

And whether the monsoon climate is unstable counts.

You can do all of this, and it doesn't cost money.

Can you come with something that doesn't have it?

Organize the answer = put the set on it, and then change it again.

No. That's what I thought.

Okay, good, you've helped me a lot.

The monsoon climate is unstable, and it should be a significant monsoon climate.

Rain and heat at the same time.

Nature: There are many tributaries and lakes in the Yangtze River Measures: Construction of reservoirs.

Man-made aspect: unreasonable occupation of river channels, greatly reducing flood capacity, increasing the possibility of flooding Measures: prohibit the indiscriminate felling of trees in the upper and middle reaches, return farmland to lakes, and strengthen river dams downstream.

Pick someone else's!! Hope it helps!!

No one repairs the flood control levees, and they are often reinforced only when the flood water rises in the summer, and basically no one takes care of ...... usually

The natural cause is that the eastern monsoon area is affected by the summer monsoon, the precipitation in the basin is abundant, the middle and lower reaches are low, and there are many tributaries, and the flood flows into the main stream of the Yangtze River in case of rain, so the Yangtze River is easy to induce flood disasters in the rainstorm season.

The flood disaster in the middle reaches is more serious, and the man-made reason is to enclose the lake to create farmland, and the upstream is indiscriminately cut and deforested, and no attention is paid to soil and water conservation.

The middle and lower reaches of the Yangtze River are prone to flooding and are related to the local latitude, and in the months of each year, due to the influence of the quasi-stationary front, a long period of rainy weather will form in this area, that is, "plum rain" weather. Heavy precipitation is the main cause of flood disasters.

1.Precipitation is concentrated in summer. The middle and lower reaches are low-lying and flat.

2.The basin area is wide and the catchment area is large, especially in the year when the summer monsoon is abnormal, the north and south tributaries enter the flood season at the same time, and the flow increases sharply.

3.Vegetation was destroyed, steep slopes were cleared, and lakes were enclosed to create fields. Soil erosion is serious, the water level is rising, and the flood storage capacity of the lake is reduced.