Climate Change and Fire in Song Dynasty

First, the relationship between climate and fire There are many factors that affect fire, but the climate factor is undoubtedly the most important. Because whether it is man-made fire or natural fire, it must depend on suitable climatic conditions. The so-called suitable climatic conditions mainly include two aspects: First, it refers to dry weather. Generally speaking, except for some chemical substances, the moisture content and drying coefficient of most solid substances are positively correlated with the relative humidity of air, and the moisture content is the prerequisite for ignition. Like wood, the higher its water content, the less flammable it is. Even if it burns, it releases less energy and spreads slowly. So when the air humidity is high, there are relatively few fires, and when the air is dry, there are relatively many fires. For example, for three years in Dazhong, Sheng, Hong, Runzhou and other places, the air was too dry and fires occurred frequently because it didn't rain for a long time. In the first year of Ming Dow, Kaifeng banned fire, because the pot was close to the wooden wall and burned for a long time. The second refers to windy weather. The importance of wind to fire is that it can support burning and spreading. According to estimates, the distance from Fei Huo can reach 500-700 meters in a five-level gale; Among the six-level gale, the farthest from Fei Huo is 27 kilometers, which easily leads to the rapid spread of fire. For example, during the Tongzhi period, a fire broke out in Boluo County, Huizhou City, Guangdong Province. Due to the fierce hurricane, insufficient manpower and heavy losses, the whole city of Boluo was reduced to ashes, and public and private businesses were in chaos. In the fourth year of Xichun, there was a fire in Shinan, Ezhou. On a stormy night, there were more than 1,000 burnt offerings. In addition, some special meteorological factors will also directly cause fires, especially lightning strikes. Many lightning strikes and fires have been recorded. For example, in June of the fourth year of Yuanfeng, the city house of Leizhen in Qinzhou was burned; In June of seven years, Yu Qing took care of the palace disaster. On the night of the fire, thunder rumbled and stopped at dawn. However, due to the climatic conditions and geographical environment at that time, lightning fire was not common. Therefore, for most fires, effective air humidity is the main external influencing factor, and the climatic factors affecting air humidity are the alternation of dry and wet seasons caused by seasonal changes in the short term and the periodic changes of climate in the long term. Journal of China Geo University: Study on Climate Change and Fire in Song Dynasty II. In the short term, the relationship between fire and climate is mainly reflected in the temperature difference between the four seasons and the change of dry and wet conditions caused by the change of the four seasons, which directly affects the probability of fire in different seasons. But before discussing the seasonal trend of fire in Song Dynasty in detail, we should first sort out the statistical data of fire in Song Dynasty according to the time of occurrence and classify them according to the grade, so as to accurately understand the annual, monthly and seasonal trend of fire. In addition to the Official History of the Five Elements, this paper also compares the fire records in other historical books of the Song Dynasty, including The History of the Song Dynasty _ Five Elements, The Long Series of Continued History, The Chronicle Since the Establishment of Yan State, Miscellanies of the Ruling and Opposition since the Establishment of Yan State, and the fire records in note novels and local chronicles of the Song Dynasty. There are quite a lot of historical materials about fire in these documents, but some of them are vague and even the time and place can't be verified. Roughly speaking, there were about 7 10 major fires in the Song Dynasty. First of all, we should consider whether they are disasters, and those without T are not included. However, there are many fires, and the specific time of occurrence cannot be verified. Therefore, among these 7 10 fires, only 529 fires can be inferred from their specific months, and 6 10 fires can be inferred from their specific years. Due to the limitation of personal ability and data, statistics may be omitted

Because the descriptions of the fire in the Song Dynasty were very detailed, and some were too brief, it was difficult to score the fire. Therefore, the number of different levels of fires counted in this paper is only a rough figure. Table 1 Song Dynasty Fire Classification Fire Level Fire Performance Keywords: Fire Times 1 Less Casualties and Property Losses 10 There are many burns, and hundreds of people are killed, and there are many casualties and property losses. There are hundreds of people burned in the second-class medium fire, and there are hundreds of people in the jurisdiction, thousands of people burned and dozens of people died, and the casualties and property losses are about 470 ~.

More than 10,000 houses were burned, and tens of thousands of districts burned for hundreds of miles. Thousands of people died, burned out, burned out. Table 2 Seasonal differences of fire in Song Dynasty. The number of major fires in spring, summer, autumn and winter is1741kloc-0/69158, and the number of major fires is 3218143/kloc-. Seasonal change trend of fire. On the basis of sorting out the fire data in Song Dynasty by month, year and scale, the number of fires in each season is counted, and then the monthly change trend of fires in different seasons in Song Dynasty is obtained, which makes the fire situation in each season in Song Dynasty concrete and can further analyze the difference of fire distribution in each month. Figure 1 shows the frequency and changing trend of fire in each month of Song Dynasty. According to the data in figure 1, it can be seen that June, July and August are the least prone to fire in summer and autumn, and the number of fires in these three months only accounts for 14% of the whole year, especially in July at the turn of summer and autumn, which is the lowest point in the whole year, with only 22 fires, accounting for only 4% of the whole year. On the contrary, 65438+February, 65438+ 10 and February in winter and spring are the three months with the largest number of fires in a year, and the total number of fires accounts for 36% of the whole year. Among them, February is the peak month of the whole year, and the number of fires in one month accounts for 13% of the whole year, which is almost equivalent to the sum of the number of fires in June, July and August. From the distribution of major and above fires, the monthly distribution trend is basically the same as that of general fires, especially in spring and winter,165438+1October, 65438+February and February, and 54 fires occurred in March, accounting for 39% of the whole year. June, July and August are the least in summer and autumn, and March is 13 times, accounting for only 9% of the whole year, of which July is only 3 times. Difference of fire situation between winter and summer in Song Dynasty. In climatology, the vernal equinox and autumn are generally divided into two parts, and the colder half is half a year in winter; The warmer half year is the summer half year, and a notable feature of monsoon climate is that the four seasons are cold and warm, and the wet and dry are distinct: spring is dry and windy, and the two most important climatic conditions that cause fires are met, so spring is generally the peak of fires, and dry and windy are the most likely to occur. As the second peak of using fire in winter, besides the dry climate, there are two factors, namely, cold and short sunshine: in monsoon climate areas, winter is generally the lowest temperature in the whole year, so it is natural to use open flames for heating; In winter in the northern hemisphere, the nights are long, the days are short, and the illumination time is longer than the general seasons. These two factors naturally become two hidden dangers of winter fires. As for summer, although it is wet and rainy, fires are difficult to happen, but there are many lightning strikes in summer. Of the 18 lightning strikes in the Song Dynasty counted in this paper, 12 occurred in summer, and high temperature and no rain in summer easily caused spontaneous combustion, so the number of fires in summer was relatively higher than that in autumn. In autumn, the temperature is neither cold nor hot, and there are few windy days; The air humidity is higher than that in spring and winter, and there are fewer thunderstorms, so autumn is the season with the lowest fire frequency. Three. Relationship between periodic climate change and fire in song dynasty. The relationship between fire and climate mentioned above is mainly discussed from the perspective of short-term seasonal changes. However, the relationship between fire and climate is not only reflected in the natural fluctuation of temperature caused by short-term seasonal changes, but also in the periodic changes of climate in a long period of time. Due to the obvious influence of monsoon climate in China, the cold period is parallel to the dry period. The warm period is parallel to the wet period, and the most important factor affecting the fire is the change of air humidity. Therefore, in this long-term climate, the alternate evolution of warm and wet and cold and dry will inevitably affect the inter-annual trend of fire. According to Zhu Kezhen, in the past 5,000 years, the climate in China and China experienced several warm and cold alternations, especially in the Song and Song Dynasties, when the climate in China changed from warm to cold in the United States for 2,000 years. This turning period experienced the warm period of Tang and Song Dynasties, the cold period of Southern Song Dynasty and the warm period of Yuan Dynasty, and the temperature fluctuated greatly. In addition, according to the general view of climatologists at present, this period is still in the warm period of the Middle Ages, connecting the warm period of the Ming and Qing Dynasties and the Little Ice Age. However, during this warm period, the climate in eastern China experienced two relatively warm periods and one relatively cold period. In a word, the climate in Song Dynasty was unstable, and the temperature fluctuated significantly and frequently, which also made the fire show a fluctuating trend with the climate fluctuation. In order to explain the relationship between climate change and fire distribution in Song Dynasty, according to the records in the literature, we classified and counted the fires in East China in Song Dynasty by year, and compared them with the temperature changes in this period. Contrast figure 2, the temperature change curve in East China in Song Dynasty refers to the temperature sequence chart drawn by Ge Quansheng. From the interannual change of fire frequency, the distribution of fire in Song Dynasty is weak at both ends and strong in the middle; In terms of temperature change, the temperature was relatively high in the middle and early northern song dynasty and the middle and late southern song dynasty, and the temperature was relatively low at the turn of the song dynasty.

Especially1120165438 From the end of the Northern Song Dynasty to the beginning of the Southern Song Dynasty, the fire frequency reached the highest level since the Song Dynasty. During these 30 years, there were 133 fires, accounting for 22% of the total number of fires in Song Dynasty. Among them, there were 14 major fires, accounting for13 of the total number of major fires in the Song Dynasty, such as the Yangzhou fire in the third year of Jian 'an; In the first year of Lin Shaoxing, Anzhou, Yuezhou, Xuanzhou and Lin Shaoxing were two years, Lin Shaoxing was six years, Lin Shaoxing was ten years, and Shaoxing was eleven years. Wuzhou and Jiankang were exactly the coldest periods in the Song Dynasty. As can be seen from Figure 2, on the trend chart of climate change, the temperature in this period is also at a low point. Therefore, climate change is closely related to the number of fires, and they are negatively related. Relationship between annual change of fire frequency and temperature fluctuation. However, although Figure 2 reflects the relationship and trend between these two variables, it is impossible to see the degree of correlation between them. Therefore, we use the product-difference method to calculate the correlation coefficient between two variables to reflect the correlation between temperature deviation and fire times. The correlation coefficient is expressed by the Latin letter R, and its value range is-1r65438+1RGT; ; 0 is a positive correlation,-1RLT; 0 is negatively correlated, and r=0 is irrelevant. According to the formula: r=xy-nnxy, the result shows -0747r-052 1, that is to say, the correlation coefficient between fire frequency and average temperature anomaly is -052 1, and the minimum correlation coefficient with temperature anomaly is -0747. Therefore, there is an obvious negative correlation between the occurrence of fire and the change of temperature, that is, the lower the temperature, the greater the possibility of fire, and the higher and stronger the correlation between them. Or vice versa, the correspondence between the climate change between Dallas and the auditorium and the high-frequency and low-frequency fire period. According to Figure 2, after further superimposing the temperature change and fire frequency in the Song Dynasty in 320 years, it is found that there is a roughly synchronous * * * vibration relationship between high-frequency fire period and cold climate change, periodic climate change and its degree of change. The cold period of almost every climate cycle corresponds to the high incidence of fire; The warm period of each climate cycle also roughly corresponds to the low frequency period of fire. Based on this, we can roughly infer several relatively high-frequency and low-frequency periods of fire in Song Dynasty, as well as the relatively cold and warm periods of climate, and their corresponding relations. Table 3 Start and end time of ground climate period/annual duration/annual temperature anomaly/fire frequency above major1960110915003280184503 cold period1/kloc +02748004 122 1504 consists of 100 13 10s) and 1 cold period. The warmth of the two warm periods is almost the same, and the temperature only changes between 0 1. But the temperature difference between the cold period and the two warm periods is 0.6~0.7. For 320 years in Song Dynasty, the start and end periods of these two warm periods and one cold period were 960 1 109 respectively. 200 1279; 1 1 01-199. For the convenience of description, we marked these three climatic periods as warm period1,warm period 2 and cold period1,corresponding to two low-incidence periods and one high-incidence period. According to the data in Table 2, the number of fires in the warm period 1 is 67 times that in the cold period 1, but the warm period 1 lasted for 150 years and the cold period 1 only lasted for 90 years. Therefore, the fire frequency of cold period 1 is much higher than that of warm period 1. The duration of warm period 2 is almost the same as that of cold period 1, but there is a big difference.

Of course, the comparison of the number and frequency of major fires can illustrate this point. There were 54 major fires in the cold period 1, which not only exceeded the warm period 2, but also exceeded the longer warm period 1. Compared with the number of major fires, the gap between the cold period of 1 and the two warm periods is even greater. 1 There were 23 major fires in the cold season, four times more than the sum of the two major fires in the warm season. In short, in the warm period, the number and frequency of fires are much less and much lower; However, in the cold period, the number and frequency of fires are getting higher and higher, and this trend is more and more obvious with the increase of fire level. Four. To sum up, through the discussion on the relationship between fire and climate change in Song Dynasty, we mainly draw the following conclusions. First of all, there is a close relationship between fire and climate, in which strong winds and dry climate conditions are the most prone to fire. Secondly, judging from the short-term climate change, the seasonality of fire is very obvious. Fires often occur in cold and dry winter and spring seasons, especially in lunar calendar 165438+ 10, 65438+February, 65438+ 10 and February. Thirdly, from the long-term fluctuation of temperature, the occurrence of fire is negatively correlated with the change of temperature, that is, the lower the temperature, the higher the frequency of fire and the greater the harm. The higher the temperature, the lower the fire frequency and the less harm. Refer to He Gang. Analysis of binary linear regression relationship between fire and meteorological factors. Fire science and technology, 2005. Li Dao. Continuation of capital management. Beijing: Zhonghua Book Company 1979. . Su Shi Ji). The complete works of Wen Yuan Guscu. Get rid of the history of Song Dynasty. Tuotuo Jinshi Beijing: Zhonghua Book Company, 1975. Liu Nanwei. Physical geography. Beijing: Science Press, 2007. Zhu Kezhen and China are nearly 5,000. And other people's research on the temperature changes in China in the past two thousand years. Progress of natural science, 2004. Ge Quansheng, wait. Temperature changes in eastern China in recent 2000 years. Quaternary research, 2002. 1977. Journal of China Geo University Volume 14 No.2 20 14 March Journal of China Geo University 20 14 March Stock Price Fluctuation, Wealth Effect Analysis and Monetary Policy Response Based on Dynamic Stochastic General Equilibrium Model Yang Abstract: This paper is based on an open It is found that in order to achieve the stability of the real economy and exchange rate, when the wealth effect increases, the central bank's response coefficient to stock price changes should be moderately increased; When the fluctuation range of stock increases, its response coefficient to stock price changes should be moderately stable. Therefore, the central bank should respond appropriately to stock market fluctuations according to the degree of interest rate marketization, wealth effect and stock market operation in China. Wealth effect; Stock market; Non-fundamental influence; China monetary policy library classification number. : F8309 document identification number: document number:1671016902009013 Fund project: Research on inflation expectation management of social science fund projects in Shaanxi Province.