Analyze the climatic causes of drought and flood disasters in the middle and lower reaches of the Yangtze River? thank you

1, the monsoon climate is unstable, and it will appear in some years when the rainy season stays for a long time.

2. In addition to the main stream, there are many tributaries in the north and south of the Yangtze River, which makes the frontal rain belt affect a wider area, last longer and exert greater pressure on the main stream in the process of advancing from south to north.

3. The river has a large curvature and poor water removal capacity. For example, the Jingjiang reach can be cut straight. The middle and lower reaches are flat, with small river drop and slow water flow, which is easy to deposit. )

4. The lake area is greatly reduced, and the water storage capacity is greatly weakened. For example, reclaiming land from lakes and so on. Now we advocate returning farmland to lakes.

5. Soil erosion caused by human activities, the contradiction between man and land caused by excessive population expansion (many people live directly in flood control areas), and so on.

In short, there are both natural disasters and man-made disasters. But there have been floods since ancient times, mainly because the climate in monsoon region is extremely unstable.