Abstract:
Data on minimum day air temperature after wheat elongation was collected over a period of 20 years from 37 agro-meteorological observation stations in Huanghuai wheat production zone and the environs. Using the data, cumulative occurrence probability of temperatures lower than 0℃(
G＜0℃)and -1.4℃(
G＜-1.4℃) were statistically analyzed. Results indicate variations in
G＜0℃and
G＜-1.4℃ with time are well described by exponential functions. Variations in area of
b value, function characteristic parameter,and approximate termination dates of air temperatures lower than 0℃ and -1.4℃ were also analyzed. Based on the occurrence probability of low temperatures and spatio-temporal variations in wheat elongation time, potential areas of frequent frost occurrence were delineated. Finally, application of b value in frost prevention strategies was discussed.
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