摘要
以甘肃民勤治沙综合试验站数十年气象定点观测资料为基础,统计、分析了民勤荒漠区无霜期、春季低温、冻土层的变化特征。结果显示:该地区平均终霜期为5月10日,初霜期为9月28日,50 a来终霜期有逐渐提前、初霜期有逐渐推后的趋势,但不同年份变异幅度增大;3-5月份地表平均最低温度、气温逐渐上升,≤0℃出现比率下降,但4月下旬至5月上旬大强度的降温天气时有发生;3月份冻土层的变化与气温变化趋势相近。30 a以来地表平均日最低温度和气温亦有所提高。
According to the meteorological observation in Minqin Desert Control Experiment Station ,variations of frost-free period, low temperature in spring and frozen earth were analyzed. The results show that the mean latest frost is on the 10th of May, the mean Grst frost is on the 28th of September, the latest frost gradually has been moved up, and the Grst frost has been put off, but the amplitude of variation within different years increases. The mean lowest temperature on the earth ＇ s surface and air temperature gradually increase from March to May, ratio of ≤0℃ day decrease. The temperatures go up, but stronger low temperature sometimes happens in the last ten-day period of April and the first ten-day period of May. The trend of frozen earth variation is same with temperature.
出处
《防护林科技》
2007年第3期1-2,29,共3页
Protection Forest Science and Technology
基金
国家"十五"重点科技项目(2002BA517A-09)
关键词
民勤
无霜期
春季
地表低温
气温
Minqin
frost-free period
spring
low temperature on the earth＇ s surface
air temperature
