What's the harm of cold wave?

1. Freeze injury of crops (most serious in autumn and spring)-strong cooling.

2. Blow down the boat, destroy the building, destroy the farm-gale.

3. Power lines crush telephone poles-heavy snow and freezing rain.

Cold wave strikes, cold wave and strong cold air usually bring strong winds and cool weather. Cold waves and strong winds are a great threat to coastal areas, such as the cold wave on April 2 1 ~25, 1969. Strong winds hit China's Bohai Sea, Yellow Sea, Hebei, Shandong, Henan and other provinces, with land winds of 7~8 and offshore winds of 8~ 10. At this time, it was the astronomical tide, and the outbreak of cold wave caused the rare storm surge in Bohai Bay and Laizhou Bay for decades. On the northern shore of Shandong Province, the sea water rose by more than 3 meters, washed away the seawall by more than 50 kilometers, and the sea water flowed backwards for 30~40 kilometers.

The freezing rain, snow and ice weather brought by the cold wave is extremely harmful to transportation. For example, 1987 1 1 A cold wave process in the last ten days caused the turnouts of several stations under the jurisdiction of Harbin, Shenyang, Beijing and Urumqi to freeze, the tracks were buried by snow, the communication signals failed, and the train operation was blocked. After the rain and snow, the roads were frozen and skidded, and traffic accidents increased obviously.

Cold wave is very harmful to human health. The windy and cool weather can easily lead to colds, tracheitis, coronary heart disease, cor pulmonale, stroke, asthma, myocardial infarction, angina pectoris, migraine and other diseases, and sometimes make patients worse.

Few people mention that the cold wave also has beneficial effects. The research and analysis of geographers show that the cold wave contributes to the heat exchange on the earth's surface. With the increase of latitude, the energy received by the earth from solar radiation gradually weakened, so the earth formed tropical, temperate and cold zones. The cold wave injects a lot of cold air into tropical areas, which makes large-scale heat exchange on the ground, which is very helpful to maintain the ecological balance of nature and maintain the lush species.

Meteorologists believe that the cold wave is the guarantee of good weather. China is affected by monsoon, and the winter climate is dry, which is a dry season. However, whenever the cold wave invades the south, it will often bring a wide range of rain and snow weather, alleviate the winter drought and benefit crops. Why can the agricultural proverb "Xue Ruizhao has a good year" be circulated among the people for generations? This is because snow water has a high nitrogen content, which is more than five times that of ordinary water, and can greatly increase the nitrogen in the soil. Snow water can also accelerate the decomposition of soil organic matter, thus increasing the organic fertilizer in the soil. The heavy snow covered the overwintering crops and played the role of a quilt, keeping out the cold and keeping warm.

There is a folk saying that "it is not cold in winter and not rich in the coming year", which also has its scientific truth. Experts in crop pest control believe that the low temperature brought by the cold wave is the most effective natural "insecticide" at present, which can kill a large number of pests and germs lurking in the soil for the winter, or inhibit their reproduction and reduce pests and diseases in the coming year. According to the survey data of agricultural technology stations around the country, pesticides can be saved by more than 60% in the year of heavy snow and winter closure.

Cold waves can also bring wind resources. Scientists believe that wind is a valuable energy source without pollution. The power generation efficiency of the world-famous Miyakojima wind power station during the cold wave is 1.5 times that of the usual one.

The east-west length of the cold wave can reach several hundred kilometers to several Qian Qian meters, but the thickness is generally only 2-3 kilometers. The moving speed of the cold wave is tens of kilometers per hour, which is similar to the speed of the train. There are three routes that affect the cold wave in China: ① West Road. This is the earliest and most frequent route in China. Strong cold air starts from the Arctic, goes south through western Siberia, enters China and Xinjiang, and then invades North China, Central Plains, South China and even Southwest China along the Hexi Corridor. ② Middle road. Strong cold air flows from Lake Baikal in Siberia and the People's Republic of Mongolia, passes through Inner Mongolia Autonomous Region, enters North China and reaches the southeast coastal areas. ③ East Road. Cold air flows south from the northeast of Siberia, sometimes through the northeast of China, sometimes through the Sea of Japan and the Korean Peninsula, and invades the eastern coast of China. The main force of the cold wave going south from this route is eastward, which is generally not very strong and the frequency will not be too much.