news

According to Xinhua News Agency 19 news: local time on March 18 afternoon, in the seaside town on the south coast of New South Wales Ta Sila, more than 70 buildings were burned fires, including 35 residential houses, in addition to more than 200 The affected residents have been evacuated to nearby beaches and the Bega evacuation centre. The NSW Fire Department stated that as the work progresses, this figure may continue to increase. The NSW Fire Department said that the fire had eased after more than 150 firefighters worked overnight. However, the fire has spread over 1070 ha. It has not been fully controlled and is still in a state of alert.

From the beginning of the year to the present, Australia has made three consecutive fires

1, January 10, 2018, Australia experienced hot weather, fires still occur in some areas. Among them, on the outskirts of Melbourne, the capital of Victoria, mountain fires spread rapidly, destroying some of the local buildings and houses.

2, March 10, 2018, Australia Bunbury, uncontrolled fire spread to the eastern part of Banbury, close to nearby houses, the residents have been evacuated.

The Relationship Between Four Meteorological Elements and Forest Fire

(1) Temperature

The higher the temperature, the easier it is to evaporate, and the more dry the litter and tiny combustibles in the forest, the easier it is to ignite. When the temperature is low, even if there are forest fires, the combustion will be slow. In daily fire risk forecasting, daily maximum temperature is often used to reflect the daily fire weather level. The higher the maximum daily temperature, the higher the daily fire risk level. The difference between the maximum daily temperature and the minimum daily temperature is called the temperature difference. When the daily temperature difference is small, the weather is often cloudy, rainy, and foggy, and the fire risk is low; when the difference is larger, it is often the case. Under the control of high pressure, the weather is clear, the warm white fever increases, and the wind speed increases in the afternoon, and the fire risk remains high.

(2) Precipitation

The greater the precipitation or the more consecutive days of precipitation, the lower the fire risk. Most of the larger forest fires are extinguished by natural precipitation or artificial rainfall increase operations to increase the precipitation. The number of consecutive dry days ( ie , the number of consecutive days without precipitation in the forest area, or the maximum number of consecutive days when the precipitation is below a certain critical value. ) The more the ground cover is, the higher the degree of fire risk is.

(3) Wind speed

In the case of dry and flammable forest fuels, the wind direction and wind speed are the decisive factors that restrict the spread of forest fires, the intensity of forest fires, the area of ​​fire, and the degree of difficulty in fighting fires. Wind speed is high and the air is turbulent. It is prone to fire whirlwinds and flying fires. The fire rises upwards, and surface fires are easy to develop into canopy fires, increasing the difficulty of fighting. The sudden change of direction will place the rescue personnel in a very dangerous situation, which can easily cause casualties.

(4) Relative air humidity

The higher the humidity, the higher the moisture content of forest fuels, the less likely to be ignited, and the lower the fire risk. The relative humidity of the air is the result of a combination of meteorological factors such as air temperature and precipitation. When the air temperature is high, the humidity is low; when the rainfall is high, the humidity is high.

The relationship between climate and forest fires

Climate conditions in a region refer to the trends and characteristics of climate elements such as cold, warm, dry, and wet over a relatively long period of time ( such as seasonal, annual, or longer timescales ) . Or average situation, including extreme conditions. It differs from and is related to weather conditions. Climate is the background of weather changes, and weather is the vibration of the climate background. In fact, it is by no means accidental that large-scale forest fires, especially catastrophic forest fires, have taken place from a climate perspective. The occurrence of forest fires often has obvious regional and seasonal characteristics. With the quasi-periodic changes of climate conditions, forest fires have quasi-periodic vibrations in their multiple years and few years. In the case of the Northern Hemisphere, larger forest fires generally occur north of the Tropic of Cancer and reach the Arctic Circle. In the high latitudes, due to the increase in sunshine hours in summer, forest fires can also occur during dry periods. From Iceland, a “forest” is formed through Scandinavia in the Nordic countries, the European part of the Soviet Union, Siberia, the Greater Xing’an Mountains in China and Changbai Mountain, North Korea, Hokkaido in Japan, Canada, the Rocky Mountains in the United States, California, and Washington. "Fire belt", in the dry year, a large number of fires occurred.

Conclusion

The future situation of forest fire insurance is not optimistic. The continuous increase in surface air temperature will advance and extend the period of fire danger, and further decrease in the temperature difference will keep the fire risk level at a high level for a long time, increase the possibility of igniting and increase the difficulty of fighting; extreme weather and climate events Frequent occurrence will increase the frequency, scope, and extent of regional high-temperature droughts, and eventually lead to the possibility of frequent fires and severe forest fires in high-temperature and drought areas.

This article is edited and compiled by China Rescue Equipment Network. Please indicate the link.