近50年北方农牧交错带气候月季变化和空间分布规律

基于33个站点1960—2010年的常规气象数据和GIS空间分析方法,分析了研究区的气温和降水的季、月以及不同区域的变化规律,以期为气候变化背景下该区域农业生产及生态建设提供科学依据。结果表明:全区平均气温50年内上升2.0℃左右,线性上升趋势明显;各季气温升高不同,冬季0.57℃/10年,春季为0.43℃/10年,秋季为0.35℃/10年,夏季为0.30℃/10年。各月的气温变化为2月份的气温50年上升了近4℃,为各月最大,波动也最明显,3、4月份次之。平均年降水量总体减少40.0mm左右。夏季降水与年降水震荡趋势相似,秋季与春季降水有一定的年际波动,不同的是春季降水略增多,秋季微减少,冬季降水变化的趋势不明显。各月中,7、8月份的降水下降幅度较大,其他月份的降水波动性大。结合分区研究表明,近50年研究区东段南部、中段西部、西段大部分地区呈现出持续的暖干化趋势。

Characteristics of climate change in seasons and months and the spatial distribution in northern farming-pastoral transition zone in recent 50 years

This paper is concerned on the characteristics of climate change in seasons,months and in different areas of northern farming-pastoral transition zone with the general meteorological data of 33 sites from 1960 to 2010.The results showed that the annual average temperature had a clear upward trend for about 2.0 ℃ in the past 50 years.The seasonal temperatures increased by 0.057 ℃/a for winter,0.043 ℃/a for spring,0.035 ℃/a for autumn and 0.030 ℃/a for summer.In particular,the temperature in February increased largely by 4 ℃ in past 50 years,following by March and April.The annual precipitation reduced by about 40.0 mm in last 50 years.The summer precipitation change was similar to the annual precipitation trends.In fall and spring,the precipitation fluctuated annually.There was a slight increase in spring,but a decrease in autumn.The precipitation decreased drastically in July and August,but no obvious regularity in other months.It was evident that the eastern section of the north area,the western section of the middle area and the most parts of the western area all had a continuous warming-drying trend.