【作者】 王旭东；

【导师】 王式功；

【作者基本信息】 兰州大学 ， 气象学， 2009， 硕士

【摘要】 阿拉善盟是内蒙古最西部的行政区,处于华北与西北和干旱与半干旱地区的过渡带。本文采用利用阿盟五个气象台站1961～2007年降水、气温资料,1966～2007年日照、蒸发量资料,采用Mann-Kendall法、滑动t检验法、Yamamoto法、小波分析等方法对阿盟47年来的降水、气温;42年来的日照、蒸发量变化趋势进行了分析,同时分析了阿盟降水量、气温、日照时数、蒸发量的突变和周期特征,计算了阿盟47年来的德马顿干燥度状况,并分析了47年来阿盟干湿演变的影响。得到如下结论:阿盟年、季平均气温均呈现总体上升趋势。阿盟年平均气温的升幅达我国年平均气温升幅的两倍之多,气候变暖趋势极为明显。阿盟区域增温的显著特点是其平均气温明显上升始于80年代中期;另一个特点是,1986年以前以冬季增温为主,后期以春、秋两季增温为主。阿盟区域的年平均气温的可靠突变点在1987～1989年之间,推测阿盟区域年平均气温未来还会有所上升。阿盟区域47年来降水呈现增加趋势,除额旗年降水量以-2.291mm/10a的速度递减外,其他站均为递增态势,但各站的年降水量增加或减少均不明显。推测未来几年阿盟区域年降水量可能稍有增加。阿盟区域年蒸发量以112.5mm/10a的速度下降,通过显著性检验。初步判定阿盟区域年蒸发量在1981年前后、1990年前后、1996年前后发生了气候突变。推测未来几年阿盟区域年蒸发量将可能继续减少。阿盟区域年日照时数气候倾向率为18h/10a,通过显著性检验,春、夏、秋季呈现弱的增加趋势,冬季则呈现弱的减少趋势,均未通过显著性检验。阿盟西南部、中部年季日照时数均呈现增加趋势,西南部表现的非常明显。突变检验表明1982年前后阿盟区域范围内日照时数发生了突变,推测未来几年阿盟区域年日照时数将可能减少。阿盟干燥度由东南部向西北部逐渐递减,大部分区域干燥度小于10,属于严重干旱地区。阿盟区域本世纪初正在缓慢变湿。巴彦浩特正在缓慢变干,吉兰太90年代至今较上一年代略微变湿,但变化不大;诺尔公、阿右旗正在变的稍微湿润,额旗正在变的越来越干燥。诺尔公的变湿趋势远强于阿右旗;额旗的变干程度远强于巴彦浩特;整个阿盟区域年干燥度的气候倾向率为0.021/10a,表明阿盟区域在趋向变湿。各站及阿盟区域年干燥度的趋势系数均未通过显著性检验,表明变干或变湿的趋势不显著。突变检验表明巴彦浩特年干燥度没有发生突变,其余各站及阿盟区域均发生了突变,吉兰太、诺尔公、额旗及阿盟区域突变发生时间集中于80年代末至90年伊始。周期分析表明1961-2007年阿盟区域年干燥度存在准8年震荡周期,表现的非常清晰,推测未来几年阿盟区域年干燥度将可能略微增加,即阿盟区域将变的略微湿润。本文研究揭示了如下事实:有关研究得出的西北气候转向暖湿化在阿盟并非十分明显,同时也指出了阿盟各地出现的暖干或暖湿倾向的差异性。总体来看暖湿倾向强于暖干倾向,但是局部(如西北部的额旗)暖干倾向强于暖湿倾向。随着阿盟气温继续升高,阿盟变干倾向将远大于变湿倾向,即暖干化远较暖湿化可信。在全球气候变暖的大背景下,阿盟各地出现的暖干(湿)化将可能对生态环境演变产生种种影响。阿盟若干地区的暖干化的变化,将加剧这一地区生态环境严重恶化的局面,局部地区的暖湿化倾向则有助于生态环境改善,但是不能根本上改变环境退化的状态。采取有效措施如退耕还林、退牧还草、禁止滥牧、开展节水灌溉、人工增雨等可以减缓生态环境压力,要注意在发展经济的同时,应置保护生态环境于首位。更多还原

【Abstract】 Alxa League, Located in far western of Inner Mongolia Autonomous Region, is trans-belt of the Northern of China and the Northwest of China, geographical arid and semi-arid belt in China. Based on the data of temperature and precipitation from 1961 to 2007 and sunshine hour and pan evaporation data from 1966 to 2007 of five station in Alxa League, the trend of temperature and precipitation during the past 47 years and trend of sunshine hour and pan evaporation during the past 42 years were discussed by means of tendency analysis, Mann-kendall test, moving t-test, Yamamoto test as well as wavelet analysis, abrupt change and period character were studied accordingly, situation of de Martonne aridity index were calculated, further more, aridity-wetness change and its impact on Alxa League were discussed since recent 47 years. The results are as follows:The annual mean temperature and seasonal mean temperature has a increasing trend as a whole, the rising of accumlative annual mean temperature in this area as much as twice than that of other regions in China which means climate warming trend is extremely clear all over Alxa League. The distinguishing features of climate warming trend in Alxa League is that Alxa League’ s regional warming turn point appeared in the mid-80’ s on the one hand, warming trend mainly relied on change of winter temperature before 1986 and change of spring and autumn temperature after 1986 on the other hand. The reliable jump point was around years of 1987, 1988 and 1989. The mean temperature may be ascend more or less in the future speculated with methods of climate prediction. The precipitation in Alxa region has increasing trend. Comparing to the descend trend in Ejina Banner at speed of -2. 291mm/10a, the annual precipitation in other four station(include Bayanhaote, Jilantai, Nuoergong, Ayouqi station) has ascend trend which there are no evidently case about the precipitation. There is slightly ascend trend in the future over the area speculated by means of climate prediction technology. The pan evaporation in Alxa region has reducing trend at speed of 112.5mm/10a which means passed t significance test. It is conducted that there is a climate abrupt phenomena around years of 1981, 1990,1996. Perhaps there is a decline case on the pan evaporation in Alxa League in the next few years. The climate tendency ratio of sunshine hour in Alxa League is 18h/10a, that is to say, that the climate trend coefficient of sunshine hour in Alxa League passed t significance test. The sunshine hour in Alxa League has slightly increasing in spring,summer and autumn comparing to slightly decreasing trend in winter. All above is not passed t significance test.It is very evidently that the sunshine hour in the southwest of Alxa League(represented by Ayouqi) has increasing trend followed by the central of Alxa League with same trend. Climate abrupt test indicates that there is an abrupt phenomena around year of 1982 on the sunshine hour. The sunshine hour may be continuous decline in next few years according to the results of climate prediction methods. Reducing step by step from the southeast of Alxa League to the northwest of Alxa League, the aridity almost over this region is under 10, which means this region is classified as severe drought area. Alxa League as a whole is turning to wetness at the beginning of 21 century. As for single station, Bayanhaote is turning to aridity slowly, Jilantai is turning to wetness from 90’s up to now comparing to last decade whose trend has little change;Nuoergong and Ayouqi is tending to wetness slightly whereas Ejina Banner is turning to drier and drier at the same time. The tendency of Nuoergong is far clearer than that of Ayouqi. The situation turning to aridity in Ejina Banner is far distinct than that of Bayanhaote. The climate tendency ratio of Alxa League as a whole is 0.021/10a which means this area is turning to wetness. The tendency of all single station and Alxa League as whole is not passed t significance test which indicates that the trend turning to aridity or wetness is not clearly. Climate abrupt test demonstrates that there is no climate abrupt change phenomenon about the annual aridity index in Bayanhaote contrasting to other station and Alxa League as a whole.The abrupt year of aridity index on study objects concentrated in the end of 80’ s and the beginning of 90’ s. It is very definitely that the annual aridity in Alxa League as a whole had quasi-eight years periodic oscillation discovered by period analysis methods.The facts revealed in this paper are as follows: The tendency of climate change from warm-dry to warm-wet over northwest of China, conducted by relevant researches, is not evidently over Alxa League. Further more, the difference among the tendency of research objects in Alxa League is pointed out. The tendency to warm-wet is clearer than the tendency to warm-wet all over Alxa League in the mass, however, local situation(Ejina Banner in northwest of Alxa League, for example.) is reverse.With continuously rising of temperature over Alxa League, the tendency to aridity is clearer than that to wetness, that is to say, the former is far more credible than the latter. Under the global warming, the tendency to wetness or aridity over Alxa League will has an impact on eco-environment in this area. The tendency to aridity will exacerbate the tensions about environmental degradation in Alxa League. On the contray,it is profitably for the surroundings of Alxa League that climate is inclined to wetness which the status of Alxa League is not turned to good direction at all.The environmental stress will be mitigated by means of converting the land for forestry and grass, banning over-herdding, carrying out policy for water-saving irrigation, artificial enhancement precipitation and so on. It is necessary that enviormental-protectting policy should be taken into account at first in pursuit of rapidly economic development at the same time.更多还原