【摘要】 依据降水的时空分布,结合气候特征和地理环境,将全市分为4个区域,并在每个区域中选取了一个代表站。在分析了晋中市秋粮产量与关键期降水关系的基础上,确定出干旱关键期,并设计出旬降水距平百分率和旬降水量距平等级这两个气象因子来确定干旱指标。通过对大气环流特征量、500百帕高度场、西太平洋海温场、地面气象要素等因子的分析,利用"最优子集回归"方法,建立了全市各区域的干旱指数预报方程。更多还原

【Abstract】 According to timespace distibution of precipitation,joining together with the climate characteristic and the geography environment,divide the whole city into four districts,and selected in each district a representative station.On the basis of analyzing the relation between autumn food yield and precipitation in key period in JinZhong,defined key dry period,and designed two meteorological factors of a period of ten days’ precipitation anomaly percentage and precipitation anomaly level,in order to define the drought index.Through analysis on factors such as atmospheric circulation characteristic,500 millibar height field,the west Pacific ocean temperature field,groud meteorological key element and so on.Take advantage of the method of "the finest subset regression",form a drought index forecast equation of each distict in the whole city.更多还原