基于19612011年东北地区88个气象站逐日气温资料,采用Kendall-Theil 线性趋势估计等方法探讨了该地区热量资源的时空变化特征。结果表明,近50多年东北地区稳定≥0 ℃积温以25~95 ℃?d/10 a 的趋势显著增加,三江平原的增加趋势明显大于东部山区。稳定≥ 0 ℃气温的起始期在东北北部和中部显著提前,终止期在北部基本显著延后,日平均气温稳定≥0℃的日数在北部和中部地区基本以2~4 d/10 a 的趋势显著增加。东北地区大部分站点终霜冻日期明显提前,初霜冻日期明显延后,无霜冻期基本以3~5 d/10 a 的趋势显著增加。稳定≥10 ℃积温以30~110 ℃?d/10 a 的趋势显著增加,稳定≥10 ℃气温的起始期北部地区显著提前,终止期南部地区显著延后,作物有效生长期在中部和北部地区基本以2~4 d/10 a 的趋势显著增加。
英文摘要:
Northeast China (NC) is an important commodity grain base with strategic role in China. The variations of heat resources and their influences on agriculture in this region are greatly of concern under global warming conditions. Here the spatial and temporal distributions of variations and trends in heat resources are analyzed using datasets including homogeneous daily mean and minimal air temperature observations at 88 sites in NC during the period from 1960 to 2011. The Kendall-Theil robust line method is employed to estimate the slopes of the daily mean and minimal air temperature time series. The results show that accumulated temperature steadily above 0 ℃ increased by 25-95 ℃?d/10 a. The magnitude of increasing trends of the accumulated temperature in Three Rivers Plain area in NC are obviously larger than corresponding values in eastern mountain regions. The starting dates have been brought forward significantly in northern region (including Heilongjiang Province and Hulunbeier city and Xinganmeng area in Inner Mongolia Autonomous Region) and central region (including Jilin Province) of NC. The end date has been delayed significantly in northern part of NC. The number of days in which daily mean temperature steadily above 0 ℃ significantly increased by 2-4 d/10 a in northern and central parts of NC. The starting date of frost-free period has been significantly advanced and end date significantly delayed over most of NC. The number of frost free days significantly increased by 3-5 d/10 a. The accumulated temperature steadily over 10 ℃ increased by 30-110 ℃/10 a. This change is more prominent in northern part of NC than that in the southern of NC. The beginning date of daily mean air temperature steadily over 10 ℃ has been brought forward significantly in northern part of NC. The end date of daily mean air temperature steadily over 10 ℃ has been delayed significantly in southern part of NC. The effective growing seasons have been significantly lengthened by 2-4 d/10 a in northern and central part of NC.