Based on the meteorological data of wheat growing season in Shangqiu during 1963 -2007, the occurrence regularity of dry hot wind during the growth period of wheat was systematically studied, and the reason for its formation was further analyzed.The results showed that the frequency of dry hot wind of wheat in this area was 7-8 in 10 years, and the annual rate of heavy disaster was 5-6 in 10 years. Compared with the conventional year,the frequency of occurrence of dry hot wind was reduced,the degree of harm had eased trend;during the period, there was a reduction in the dry hot wind from late May to early June;spatial distribution presented the characteristics of southern and central light,and the eastern and northwestern heavy in dry hot wind.In terms of the causes,the area of sunny weather,high temperature,rel-atively dry air could help dry and hot climate;in addition,selection of late maturing varieties,excessive application of nitrogen fertilizer and ir-rigation amount or late some man-made factors might also lead to the occurrence of dry and hot wind.%以1963—2007年商丘市小麦生长季的气象数据为资料,系统地研究了小麦生育期干热风发生规律,并深入分析了形成的原因.结果表明,该区小麦干热风发生频率为10年7~8遇,重灾年率为10年5~6遇.与常年相比,干热风的发生频率呈现有所减少、危害程度呈现有所减轻的趋势;时期上呈现干热风5月下旬—6月上旬减少的态势;空间分布上呈现干热风南部和中部轻、东部和西北部重的特征.形成原因方面来看,受气流影响该区天气晴朗、温度较高、空气相对干燥都有助于干热风气候的出现;另外,选择晚熟品种、氮肥施用过量、灌水量少或过晚等人为因素也可能导致干热风的发生.
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