近45年阿克苏地区干湿程度演变分析

采用近45年来阿克苏地区年、季气温、降水序列,并通过对各站干湿指标序列的考察,分析了阿克苏地区年代际、年、季干湿状况的变化.结果表明:阿克苏地区年平均气温的增加快于年降水量的增加,两者均以冬季增加为主,临近沙漠地带夏季气温和秋季降水呈微弱的下降趋势.干湿指标分布自山区经平原向沙漠由湿向干变化,由于各区域间降水差异较大,沙漠边缘地带比山区小近30%.阿克苏地区的干湿变化呈现出山区和浅山地带持续增湿,平原增湿速率逐渐减小,局地转为干旱化的特征.

Analysis on the Evolvement of Dryness/wetness in Aksu Prefecture in Recent 45 Years

In this paper,the decadal,annual and seasonal changes of dryness/wetness in Aksu Prefecture in recent 45 years are analyzed using the annual and seasonal air temperature and precipitation data observed by the meteorological stations in Aksu Prefecture in recent 45 years based on the dryness/wetness values at the stations.The results reveal that the increase of annual air temperature is higher than that of precipitation,and both annual temperature and precipitation increases occur mainly in winter,especially the air temperature in summer and precipitation in autumn in the regions near the deserts are slightly decreased.The dryness/wetness values reveal that the wetness becomes gradually towards the dryness from the mountainous region to the deserts,and the dryness/wetness value in the mountainous region is about 30% lower than that in the marginal zone of the deserts because of the precipitation difference.The wetting rate is continuously increased in the north mountainous region and the west low-mountain zone but decreased gradually in the east plain.Humidity increase in Aksu Prefecture in recent 20 years is directly related to the increase of precipitation,but aridity occurs in some regions.