How to define plum blossom fragrance into plum blossom fragrance out?

Plum entry and flowering are mainly determined by precipitation, duration, temperature and humidity.

Plum entering and plum leaving are commonly used words to describe the summer monsoon stage, which are mainly used to distinguish the start and end time of plum rain season in southern China. Plum entering is the beginning of rainy season in Mei Fang, which can also be understood as the coming of rainy season. In meteorology, the rainy season usually refers to the period when there is more precipitation and higher temperature due to the interaction between warm and humid air and cold air during the summer monsoon in southern China.

1, precipitation: Before entering Mei, the climate was generally dry with little precipitation. When the continuous precipitation with increasing intensity begins to appear in the southern region for a period of time and reaches a certain threshold, it can be judged that it has entered Mei. Under normal circumstances, the standard of precipitation in Mei is that the average daily precipitation exceeds 25mm for five consecutive days.

2. Duration: In addition to the standard of precipitation, the duration of precipitation should also be considered when entering Mei. Generally speaking, it is necessary to meet the requirements of continuous precipitation when entering Mei, which means that precipitation occurs every day within a certain time range (generally more than 3 days). If there is continuous precipitation and it meets certain precipitation standards, it can be judged as entering Mei.

3. Temperature and humidity: During the plum blossom period, the weather is sultry, with high humidity and relatively high temperature. When the average temperature in southern China begins to rise, reaching a certain temperature threshold (generally above 28 degrees Celsius), and the relative humidity increases to a certain extent, accompanied by continuous precipitation, it can also be regarded as plum blossom.

Contrary to entering the plum blossom, leaving the plum blossom refers to the process of ending the rainy season in the south. The definition of plum blossom also includes the following factors:

1. Precipitation: Before Plum Blossom, precipitation in southern China gradually decreased, and precipitation activities in rainy season came to an end. Plum blossoms usually need 5 consecutive days of low precipitation (generally less than 10 mm) or no precipitation.

2. Duration: No matter how much precipitation, it is important to achieve a state of continuous non-precipitation during the plum blossom period. In general, plum blossoms need to meet the requirement of continuous no precipitation, that is, there is no precipitation within a certain time range (generally more than 3 days).

3. Temperature and humidity: At the time of plum blossom, the temperature in the southern region began to cool down and the humidity gradually decreased. When the average temperature drops below a certain temperature threshold (usually below 26 degrees Celsius) and the relative humidity shows a low level, it can be considered as the beginning of plum blossom.

The specific definition standards of plum entry and plum exit may be slightly different, because these standards may be adjusted in different meteorological departments and regions. In addition, the specific dates of entering and leaving Mei are also affected by climate change, so the dates of entering and leaving Mei may fluctuate from year to year.

Plum entry and flowering are mainly determined by precipitation, duration, temperature and humidity. For most areas in the south, entering the plum blossom means the beginning of the rainy season in summer, and leaving the plum blossom means the end of the rainy season. Accurately judging the entry and exit of plum blossoms is of great significance to agriculture, transportation, disaster prevention and other aspects, so local meteorological departments will make scientific judgments and forecasts according to the actual situation.

The harm of plum rain

1. Flood: The heavy rainfall during the Meiyu period may cause the water level of rivers, lakes and other water bodies to rise and even overflow the banks; Geological disasters such as mudslides and landslides may occur in mountainous areas. Floods will cause farmland to be flooded, road traffic will be interrupted, and even people's lives and property will be threatened.

2. Water pollution: The heavy rainfall during the Meiyu period will easily lead to the overload operation of the urban drainage system, and the sewage pipes may overflow, causing sewage to enter rivers, lakes and seas, causing water pollution and bringing harm to the water supply ecological environment.

3. Disease transmission: The rainy season is warm and humid, which is the season for germs, bacteria and viruses to breed. For example, mosquito breeding may spread diseases such as malaria, dengue fever and Zika virus; Humid environment is also conducive to the growth of mold, which may lead to respiratory infections and other diseases.

4. Disaster situation of crops: heavy rainfall and short sunshine time during the Meiyu period are unfavorable to the growth and development of crops. Long-term humid environment is easy to cause crops to be attacked by fungal diseases and bacterial diseases, and even affect the yield and quality of crops.