The reason for the rain

The main causes of rainfall are water vapor condensation, cloud cooling and topography.

1. The condensation of water vapor is the basis of rain formation. When surface water evaporates or plants release water vapor through transpiration, water vapor will be brought into the atmosphere by the wind. With the increase of height, water vapor will meet low-temperature air, making it condense into small water droplets or ice crystals.

2. Cloud cooling is also a key factor in the formation of rain. When water droplets or ice crystals in the cloud are at the top or upper part of the cloud, they will be cooled by radiation. This cooling will cause the increase or decrease of water droplets or ice crystals, and eventually form raindrops. In nature, the formation of rain is a complex and subtle process, which provides the necessary water resources for life on earth.

3. The role of topography is also an important factor in the formation of rainwater. When the air flow encounters terrain obstacles, such as mountains, it will be forced to rise. The rising airflow will cause the temperature to decrease and the humidity to increase, which will further promote the condensation of water vapor and form raindrops. This kind of topographic precipitation is usually formed on the leeward slope of the mountain range.

The role of rain:

1, the role of rainwater in maintaining ecological balance is mainly reflected in providing necessary water and nutrients for life on earth. Rain can nourish the land, promote the growth of plants and provide food and water for all kinds of living things. Rainwater can also maintain the water level of rivers, lakes and other water bodies and ensure the living environment of aquatic organisms. Rainwater can also help maintain the microbial community in the soil and promote the ecological balance of the soil.

2. The role of rainwater supply is also very important. Rainwater can supplement the water sources of groundwater, rivers, lakes and other water bodies, and provide drinking water and other domestic water for people and animals. Rainwater can also supplement the water source of farmland and provide necessary water for agricultural production. Without rain, water resources in many areas will be exhausted, which will bring great difficulties to people's production and life.

3. The role of rainwater in regulating climate can not be ignored. Rain can absorb and release heat, adjust temperature and humidity, and alleviate the occurrence of extreme weather phenomena. Rain can also promote water circulation in the atmosphere, transport water to different regions and maintain water balance on the earth. Rain can also purify pollutants in the air and reduce air pollution.