山西省近50年无霜期变化特征研究

根据山西省108个地面站近50 a（1959—2008年）的初霜日、终霜日和无霜期系列数据,采用非参数Mann-Kendall检验法,对山西省近50 a无霜期的变化特点进行了研究。计算结果表明,全省108个地面站的平均无霜期在124.6~232.9 d之间。Mann-Kendall检验结果显示,在所有地面站中,77个站初霜日推后,78个站终霜日提前,87个站无霜期延长,其中35个站显著延长。全省初霜日显著推后（＋1.41 d/10 a）,终霜日显著提前（-2.57 d/10 a）,无霜期显著延长（＋3.72 d/10 a）。初霜日推后和终霜日提前对无霜期延长的贡献约分别为1/3和2/3。Pearson相关分析证明,在全省范围内,初霜日、终霜日和无霜期与年平均气温、纬度和海拔具有密切关系。直线回归分析显示,气温每升高1℃,初霜日迟4.7 d,终霜日早4.1 d,无霜期延长8.8 d。纬度每北移1o,初霜日早6.1 d;终霜日迟4.5 d;无霜期短10.6 d。海拔每升高100 m,初霜日早3.4 d;终霜日迟2.8 d;无霜期短6.2 d。对初霜日、终霜日和无霜期这些特点的认识,对本区自然和人工生态系统管理、生态恢复和生态工程实施等具有重要意义。

Variations in frost-free period in Shanxi province,China:1959-2008

A data set of the date of last spring frost（LSF）,the date of first fall frost（FFF）,and the length of frost-free period（FFP） for the period 1959-2008 from 108 surface meteorological stations was used to characterize the variations of LSF,FFF and FFP in Shanxi Province（PR China） from the aspects of every stations and provincial level with the help of nonparametric Mann-Kendall test method.The average FFP ranged from 124.6 days to 232.9 days among all the stations.A later FFF,an earlier LSF and a longer FFP were found at 77,78 and 87 stations,respectively,with a significant positive trend for the FFP found at 35 stations.Significant later FFF（＋1.41days per decade）,earlier LSF（-2.57 days per decade） and longer FFP（＋3.72 days per decade） were found over the province,and the later FFF and earlier LSF accounted for one third and two thirds of the longer FFP,respectively.The extremely significant correlations were found of FFF,LSF and FFP with air temperature,latitude and elevation within the province,with the FFF 4.7 days later,LSF 4.1 days earlier and FFP 8.8 days longer for every one degree increase in air temperature;the FFF 6.1days earlier,LSF 4.5 days later and FFP 10.6 days shorter for every one degree increase in latitude;and the FFF 3.4 days earlier,LSF 2.8 days later and FFP 6.2 days shorter for every 100 m increase in elevation.The current research would be greatly helpful for sound and effective ecosystems managements in the province.