陕西省极端气温变化特征分析

【作者】 王海燕；

【导师】 殷淑燕；

【作者基本信息】 陕西师范大学 ， 自然地理学， 2010， 硕士

【摘要】 随着全球气候变化研究的进一步深入,人们已经逐渐认识到极端气候事件对人类日常的生产和生活、社会经济、生态环境所带来的影响往往已超过长期的气候变化。基于陕西省22个气象观测站1960-2005年逐日最高气温、最低气温和平均气温资料,本文利用趋势分析、距平、Mann-Kendall突变检验法、Morlet小波分析和相关分析等方法,详细分析了陕西省极端气温变化特征。得出以下主要结果：(1)1960-2005年,陕西省年平均气温呈明显的增暖趋势,45年间上升了0.855℃,80年代到90年代,气温的增加值最高,增温表现出北强南弱的特点：陕西省年平均气温在1993年发生了增温突变,陕北、关中的突变分别发生在1994年和1995年,但是,陕南只是在1997年发生一次大的气温转折,没有突变发生；在33年的时间尺度上,陕西省的年平均温度存在着大约15年左右的冷暖交替的阶段性变化。(2)年平均最高、最低气温也均呈现明显的增暖趋势,后者的增暖幅度大于前者,陕西省与候变暖主要是最低气温的升高所致；省内各个自然区的最高、最低气温表现出不同的增温趋势,陕北和陕南年平均最高气温的增幅大于年均最低气温,关中则是最低气温的增幅大于最高气温；就陕西省平均状况而言,年平均最低温度在1993年发生了突变,年平均最高温度在1995年发生了突变；陕北和关中的平均最高温度在1994年发生突变,陕南没有发生突变,只在1997年有一次大的气温转折；陕北、关中和陕南的年平均最低温度的突变分别发生在1993、1994和1997年,北边发生突变的时间早于南边。在大约30年的时间尺度上,年平均最高和最低温度也存在着15年左右的冷暖交替的阶段性变化。(3)在1960至2005年期间,就陕西省的平均状况而言,日最高温度大于35℃的高温日数和日最低温度小于0℃的低温日数均呈减少趋势,前者减少幅度小于中国北方地区,而后者的减少幅度大于中国北方地区；陕北的高温日数却以0.62天／10年的趋势在增加,这种变化趋势严重不利于陕北干旱和沙漠化的防治以及该区生态环境的可持续发展；而关中地区的霜冻季节缩短了约15天左右,这种气温变化趋势的存在,会对关中地区农业和自然生态环境产生重要的影响。(4)就陕西省总体平均来看,白天温度异常偏高的日数趋于增多,20世纪80年代中期以后增加趋势更为明显,在1996年附近发生了突变；陕北和关中中西部的增加趋势较其它区域明显；在1960-2005年间,存在着显著的6-8年的周期振荡：同时,陕西省夜间温度极端偏低的日数也在显著减少,关中中西部的减少趋势最为显著,陕西省的极端低温日数在1990-1992年之间发生了突变,极端低温日数发生突变的时间较极端高温早：夜间温度极端偏低的日数存在6年左右的振荡周期。(5)陕西省白天温度极端偏高的日数和年平均气温、夏季平均气温之间均为正相关关系,夜间温度极端偏低的日数和年平均气温、冬季平均气温之间为负相关关系；季平均气温与极端气温事件的相关性比年平均气温与极端气温事件的相关性更为显著。更多还原

【Abstract】 With the further study of global climate change,people have gradually realized that the impact of extreme climate events on human daily production and life,socio-economic, ecological environment,which often exceed climate change does.Based on the data of daily maximun temperature,minimun temperature and average temperature from 22 meteorological stations in Shaanxi Province from 1960 to 2005,the features of extreme temperature are studied. Some classical statistical methods have been used to study characteristics of extreme temperature change,such as trend, anomalies, Mann-Kendall mutation test,Morlet wavelet analysis,correlative correlation and so on.The main findings are as follows:(1)The mean temperature are on the rose in Shaanxi Province from 1960 to 2005,about 0.855℃for the 45 years.The highest of value added is from 80’s to 90’s,the warming showed the characteristics of strong North weak South.The average temperature mutation occurred in 1993 in Shaanxi Province,and respectively occurred in 1994 in Shaanbei and 1995 in Guanzhong,but there is no mutation occurred in Shaannan,only a big turning point in 1997.0n 33 years time scale, there are about 15 years of alternating cold and warm change in Shaanxi Province.(2)The average maximum temperature and minimum temperature also showed a significant warming trend,the latter is larger than the former in Shaanxi Province, the warming is mainly caused by the increase of minimum temperature.Various natural areas in the province showed different growth temperature trend,the warming amplitudes of annual maximum temperature is greater than annual minimum temperature in north and south of Shaanxi,but there is different in the Central Shaanxi.On average conditions, the annual mean minimum temperature mutation occurred in 1993, the annual average maximum temperature mutation occurred in 1995,the maximun occurred in 1994 in Shaanbei and Guanzhong,there is no temperature mutation in Shannan,only a big turning point in 1997.From north to south,the annual mean minimum temperature mutations respectively occurred in 1993,1994, and 1997,it is much earlier in north. The variation cycle of maximun temperature and minimum are all 15 years.(3)As like as the number of days with maximum temperature above 35℃,the number of days with minimum temperature blow 0℃in Shaanxi Province had a decreasing tendency from 1960 to 2005.Compared with the North of China,the reduce amplitude of high temperature days is much smaller,but the reduce amplitude of low temperature is stronger. The number of high temperature days is increasing with a rate of 0.62 days every 10 years in Shanbei, which is seriously going against the control of drought and desertification, and ecological development of the area. The frost season reduced about 15 days in Guanzhong area, which would have a major impact on agriculture and natural environment.(4)The number of days with daily maximum temperature above 95th percentiles in Shaanxi Province is increasing,but it was more obvious after the mid-80s,and the mutation occurred in 1996.The increasing trend in Shanbei and central and west of Guanzhong area was more significant. There is a significant 6-8 year periods in 1960-2005 years. At the same time, the number of days with daily minimum temperature blow 5th percentiles in Shaanxi Province is also greatly reducing. The declining trend in central and west of Guanzhong area was the most significant. The mutation occurred in 1990-1992,which is earlier than the extreme high temperature. There is around 6 years oscillation cycle.(5) There are abvious positive relations between average temperature and the number of days with daily maximum temperature above 95th percentiles,and the abvious negative relation between average temperature and the number of days with daily minimum temperature blow 5th percentiles.Compared with annual mean temperature, seasonal average temperature had more significant correlation to the extreme temperature events.更多还原