The Analysis Of The Climatic Variation In Liaoning Province From 1956 To 2008

This thesis is based on the materials from the China Meteorological Data Sharing Service System, such as the meteorological elements of month by month or even year by year temperature, precipitation, sunshine duration, wind speed and relative humidity between 1957 to 2009 detected by 23 meteorological observing stations in Liaoning Province. This thesis analyses from the perspective of time, the interannual, interdecadal and seasonal variation tendency of the meteorological elements in Liaoning Province, as well as the cycle and mutation of the meteorological elements. This thesis also analyses, from the perspective of space, the spatial distribution of the interannual and seasonal variation of the meteorological elements. The tendency of climate change of Liaoning Province in the recent 53 years is fully discussed from the angles of both time and space in this thesis.The main conclusions are as follows:1. The interannual variation of the meteorological elements: temperature was on increase with a climatic tendency rate of 0.28℃/10a; the precipitation was on decrease with a climatic tendency rate of -18.371mm/10a; The sunshine duration was on decrease, the climatic tendency rate being -45.163h/10a; the wind speed in Liaoning Province was on decrease, with a climatic tendency rate of -0.193m/(s·10a).The interdecadal variation of meteorological elements: the interdecal variations of all the four elements except temperature showed interdecadal increase, with the decrease trend of the sunshine duration being the most obvious and the precipitation and wind speed featuring fluctuations. The seasonal variation of the meteorological elements: the temperature in all the four seasons increased, with the highest increase in winter and the slightest in autumn. The precipitation in summer dropped the most sharply, with slight decrease in autumn and winter, and slight increase trend in spring. The sunshine duration declined obviously in spring and summer, while that in winter dropped slightly. Spring has the fastest speed of wind; therefore the decrease of wind speed in spring was the most obvious followed by winter.2. The spatial distribution of the meteorological elements: in general, the temperature distribution showed that temperature increased from north to south, with obvious increase tendency in the northeast and the west Liaoning Province, and relatively weak increase tendency in the central Liaoning Province. The precipitation in Liaoning Province was on decrease from the southeast to the northwest, with the high center in Kuandian and Dandong, and the low center in Jianping in west Liaoning Province. The sunshine duration was on decrease from the west to the east, with the highest value of 2840.87 h in Jianping, and the lowest value of 2288.31 h in Xiuyan. However, the trend in Benxi and Suizhong didn't conform to the general trend, showing an increase. The wind speed in the plain area of central Liaoning was higher than that in the mountain and hilly areas in the eastern and western Liaoning, with the highest value of 4.74m/s in Dalian and the lowest value of 1.47m/s in Kuandian in the east, while the wind speed in Zhangwu and Fuxin was on slight increase.3. The cycle analysis and mutation analysis of the meteorological elements: in the span of 53 years, the temperature in Liaoning Province featured a 18~22-year cyclic vibration, but not very obviously. After 1970s, the temperature change showed an about 12-year cyclic vibration. The precipitation featured an obvious 15~16-year cyclic vibration. During the whole span, there were five higher center and five lower center; the sunshine duration in Liaoning Province featured an about 20-year cyclic vibration, and a 10-year cyclic vibration from 1957 to 1977. The change of the wind speed featured a 20-year cyclic vibration. There was no obvious cyclic vibration on other timescales. The decrease trend of wind speed was not obvious; therefore, the cycle fitted by the wavelet analysis was not very clear.The mutation of the temperature mainly happened in late 1980s and 1990s; the mutational sites of annual, spring and winter's precipitation are incredible after the test, so they didn't exist mutation, while the mutation of summer and autumn's start from about 1996～1997; the spring's sunshine duration existed mutation which started from 1974, while the autumn's is about 1982 or 1984, but there aren't obvious mutational site in annual and summer's sunshine durations; the point of intersection of the UF curve and UB curve was quite obvious, but all out of the area of the borderlines, therefore, they were not considered to be the years of jump. The changing trend of wind speed was not very obvious compared with the other three meteorological elements; therefore, it had no mutation year.4. Correlation: the sunshine duration had a positive correlation with wind speed, and a negative correlation with precipitation and relative humidity. Via the analysis of multiple stepwise regression equation, among the selected three elements, wind speed had relatively more correlation with the sunshine duration and followed by the relative humidity, the least is precipitation; wind speed had negative correlation with temperature, the average maximum temperature, and the average minimum temperature. Via the analysis of multiple stepwise regression equation, the annual, spring's, summer's, autumn's and winter's all reached a high significant level, this indicates temperature has marked correlation with wind speed and especially the average minimum temperature.