Why did Mudanjiang flood?

1. Weather factors: Extreme weather such as rainstorm, rainstorm season and tropical cyclone may cause the river water level to rise and cause floods. Long-term rainfall will lead to the increase of surface runoff and groundwater level, which will aggravate the formation of river floods.

2. Topography: The topography of rivers has a great influence on the generation and development of floods. Terrain slope, river curvature, bank width and other characteristics will determine the propagation speed and destructive power of flood.

3. Hydrological water resources: The characteristics of hydrological water resources such as river runoff, water level and river slope are closely related to the occurrence of floods. The transition between rainy season and dry season may lead to the formation of floods.

4. Human factors: unreasonable development and management activities may aggravate the occurrence and impact of floods. For example, over-exploitation leads to vegetation destruction, land degradation, soil erosion and other problems, which reduces the storage capacity of rivers. In addition, the process of urbanization, improper water conservancy projects and occupation of river banks may also lead to increased floods.

5. Climate warming: Global warming may aggravate the occurrence of extreme weather events, such as rainstorm and drought, which will lead to an increase in the frequency and intensity of floods.