大气降水环境下玉米生长期旱涝频率及防御对策

Drought Frequency and Defense Countermeasure of Maize Growth under Atmospheric Precipitation Environment

以作物生长期内供需水量比作为作物旱涝等级指标,通过对聊城市1961—2010年玉米生长期内的大气降水统计资料的分析,明确了鲁西平原地区玉米生长期内大气降水的多寡对夏玉米正常生长的影响,确定了符合玉米生长期的旱涝年景评价指标.根据旱涝指标,明晰了玉米生长期内的旱涝变化频率特征:旱涝灾害频繁,50 a中玉米生长期内出现干旱32 a,出现频率为64%.雨涝年6 a,出现频率为12%.干旱和雨涝年的频率为76%,即在大气降水环境下,玉米生长期内发生旱涝的概率大于十年七遇;作物生长期内旱涝频率各年代逐渐增大,作物因旱涝受灾呈现出明显加重的趋势,对农业生产和粮食安全的威胁愈加突出,对生态农业建设构成较大威胁.结合作物生长期内大气降水的多寡导致的旱涝频繁的特征,提出了做好抗旱涝防减灾工作的对策.

Taking water supply-water demand ratio of summer corn in growth period as summer corn drought evaluation index,through the analysis of the statistics of natural precipitation in growth period of summer corn from 1961 to 2010,the effect of the amount of natural precipitation on the normal growth of summer corn in its growth period is shown.And the evaluation index which is consistent with the summer corn in growth period in drought year or waterlogging is set.According to the drought year or waterlogging year evaluation index,the characteristics of drought and flood's varying frequencies of the summer corn in growth period are analyzed and summarized.The results show that the drought and flood disaster occur frequently.In the 50a of meteorological record,there are 32a of flood and 6a of drought.The frequency is 64% and 12% accordingly.And altogether the frequency of drought and flood is 76%.That is,under the conditions of natural precipitation,the probability of drought and flood in the growth period of summer corn is over seven years in ten years;the drought and flood disasters of summer corn present an obviously aggravating tendency.The drought and flood disasters of crops present obviously aggravating tendency in different years,the threat of which to agricultural production and food security is more outstanding.And it poses particular problem for food security and the construction of ecological agriculture.Combining the time-space distribution features of natural precipitation in the growth period of summer corn,the countermeasure of resisting drought and waterlogging and preventing and reducing disasters is put forward.