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利用河北省1981—2010年冬季逐日气象资料、冬小麦冻害灾情资料及品种资料,采用秩和检验法,依据Bayes判别准则,建立了初冬剧烈降温型、冬季长寒型和融冻型3大主要类型冬季冻害气候指标;依据风险分析原理,结合概率密度函数,建立了各类型冻害的气候风险概率指数模型,进行风险分析。结果表明:冬小麦初冬剧烈降温型冻害主要受越冬前后降温过程的降温幅度和过程最低气温影响;长寒型冻害主要受越冬期寒冷程度影响,包括越冬天数及越冬期平均气温、最低气温低于临界温度的天数及其累积负积温两个方面;融冻型冻害主要受平均气温回升到0℃以上后出现的低温过程的极端最低气温影响。北部麦区以长寒型冻害风险为主,高风险和较高风险区主要分布在唐山、秦皇岛两市中北部和保定西北部;中南部麦区以融冻型和初冬剧烈降温型冻害风险为主,高风险和较高风险区主要分布在邢台和邯郸两市东部、保定西北部。
Based on the daily meteorological data of winter 1981-2010 in Hebei Province and the data of winter wheat frost disaster and its varieties, the three major types of severe cold loss in early winter, long-cold in winter and frozen-thaw in winter were established by rank sum test and Bayes criterion. According to the principle of risk analysis and the probability density function, the climate risk probability index models of various types of frost damage were established for risk analysis. The results showed that the frost-freezing damage of winter wheat in early winter was mainly affected by the decreasing range of temperature and the lowest temperature of the process before and after overwintering. The frost damage of long-cold type was mainly affected by the coldness during winter, including the number of overwintering days and average temperature during wintering, The number of days of temperature and the accumulated negative accumulated temperature. The freeze-thawing frost damage is mainly affected by the extreme minimum temperature of the low temperature process after the average temperature has risen above 0 ℃. The northern wheat area is dominated by the cold-type frostbite risk, while the high-risk and high-risk areas are mainly located in the north-central part of the two cities of Tangshan and Qinhuangdao and the northwest of Baoding. The frost-freezing risk in mid- The main, high-risk and high-risk areas are mainly located in the eastern part of Xingtai and Handan cities and northwest of Baoding.