Abstract:

For comprehensive analysis of trends in frost 49 years and providing reference for regional crop structure adjustment and selecting appropriate species for varieties growing period, based on the meteorological data from 1961 to 2009 of 86 meteorological stations and digital elevation models (1:250 thousand) in shandong province, the method of regression analysis was adopted in calculating the first/last frost dates and frost-free period. Statistical analysis and spatial analysis were carried out 15 grid layers with the first/last frost dates and frost-free period by GIS, and the results were tested by Mann-Kendall. The results showed that: (1)in spatial, the last frost dates start with southwest, and gradually to the northeast direction from southwest, the latest were the shandong peninsula and the central mountain in shandong province; But, the latest frost date had certain changes in different area and in different age. The first frost dates start with northwest, and gradually to the southeast direction from northwest, the latest were the department of lunan and southeast coast; all the average age of frost-free periods on the number of days increasing from north to south. (2)In temporal, the latest was 70s of the 20th of the last frost date, the earliest was average of 2001-2009; The first frost date was on the contrary. The earliest was 70s of the first frost date, the latest was average of 2001-2009. The least of frost-free period were 60s, 70s of the 20th, the longest was average of 2001-2009. Tended to rate of last frost date was-2.6d/10 a, the tendency was statistically significant by 0.01's check, there was obviously ahead trend in series of last frost date. Tended to rate of first date was 2.0d/10a, it also passed a checkout, and there was obviously postpone trend in series of first frost date. Tended to rate of frost-free period was 4.6d/10 a, it also passed a checkout, and there was obviously increase trend in series of first frost date.