干热风是小麦生育后期的一种主要灾害性天气。其特点是高温低湿,而一定的风速又会加剧这一高温低湿过程。春末夏初,正值小麦从乳熟到蜡熟阶段,这时小麦最适宜的温度为日平均温度20—22℃,但最高温度超过33℃时,就会使植株光合作用大大降低,造成高温逼熟,使小麦籽粒秕瘦,造成减产。运城地区地处山西省南部,地形为周围高中间低,形成一个高原内陆盆地。由于气候和地形的原因,干热风几乎 Dry hot wind is a major disastrous weather in late wheat growth. Its characteristics are high temperature and low humidity, and certain wind speed will exacerbate this high temperature and low humidity process. Early spring and early summer, coincided with the ripening stage of wheat to wax stage, then the most suitable temperature for wheat is the average daily temperature of 20-22 ℃, but the maximum temperature exceeds 33 ℃, it will greatly reduce photosynthesis in plants, resulting in Curing at high temperatures, so that thin wheat grains, resulting in reduced production. Yuncheng area is located in southern Shanxi Province, the terrain around the middle of low, forming a plateau inland basin. Due to the climatic and topographical reasons, the hot and dry wind is almost