Influence of foehn effect

1. Negative effects: Foehn effect often dries up fruit trees and crops, reduces production, and leads to the spread of fires in forests and villages, causing losses. In mountainous areas, the foehn effect will melt a lot of snow, leading to flooding in the upper reaches of the valley and sometimes causing avalanches. Strong winds will also cause local wind disasters, such as blowing off the roofs of mountain farmhouses, blowing down crops and uprooting trees. In addition, when windy weather occurs, many people will have uncomfortable symptoms, such as fatigue, depression, headache, bad temper, palpitation and edema.

2. Positive impact: The lighter burning wind can increase local heat and make corn and fruit trees mature ahead of time. In the Rocky Mountains of North America, the snow is deep in winter, and when the wind blows in spring, all the snow melts, and the land is covered with lush grass, providing pasture for livestock.

Foehn wind is a kind of dry-hot wind formed when the temperature rises and the humidity drops when the air sinks adiabatically. It is a unique weather phenomenon in mountainous areas, which is mainly caused by the sinking of airflow after passing through the mountains. When a mass of air sinks from the sky to the ground, the temperature rises by 6.5℃ on average every time it drops 1000 meters.

That is to say, when the air drops to the ground from the mountain at an altitude of 4000 to 5000 meters, the temperature will rise by more than 20℃, which will suddenly heat up the cool climate. This is the reason for "burning the wind". Foehn can also be seen in all parts of China, such as the leeward slopes of Himalayas, Hengduan Mountain and Erlang Mountain, which have a strong foehn effect.