关键词: 应用调查, 应用调查

Abstract: Based on each year’s last frost date data and each day’s minimum ground temperature data of 62 meteorological stations in Shanxi Province from 1961 to 2010, the last frost date change characteristics and its periodicity of Shanxi Province were analyzed with Morlet analysis and Mutation test method. The results showed that: the average last frost date of Shanxi Province had an advancing trend with obvious fluctuations. Except during 1980-1989 and the time from 2005 to 2010, the average last frost dates all had advancing trend. The first decade of this century was the period that the average last frost date of Shanxi fluctuated smartly. The Morlet analysis results showed that, the main periodicity of the mild last frost, the moderate last frost and the severe last frost were 15 years, 12 years, 7 years, the secondary periodicity of the mild last frost, the moderate last frost and the severe last frost were 1 year, 1 year, 5 years. Now, Shanxi was at the stage when the mild last frost occurs in advance but the moderate and severe last frosts shift to later dates. It was found with M-K mutation test that the average last frost date of Shanxi Province had an obvious mutation in 1990, and the last frost dates of most stations in Shanxi Province had mutations, the mutation time were concentrated from 1975 to 1996, and the spatial distribution of the mutations over Shanxi Province showed as follows: the South was earlier than the North, the Central was earlier than the East and the West. Most mutations occurred in 1980s, the Midwest, Northwest, Northeast and Mideast regions were the latest areas.