河北省农作物发育期降水量时空分布特征

利用河北省地区80个气象站48年资料,通过对冬小麦、夏玉米全发育期和各发育期的降水量时空变化进行线性趋势分析,研究降水量的时空分布及变化特征。结果表明:(1)近50年河北各区域冬小麦全发育期降水量变化无明显增加或减少趋势。各区域夏玉米全发育期降水量呈线性减少趋势,从南部、中部、北部到东北部,减少趋势依次增大。(2)冬小麦在播种-出苗期,中部、南部降水量有增多的趋势,东北部降水量变化趋势不明显,北部降水量自90年代以来有增加的趋势。在分蘖-越冬期、越冬期、返青期、拔节期、成熟期,各区域降水量无明显增加或减少的趋势。在抽穗期,各地降水量年际变化波动很大,南部、中部降水量呈线性增加趋势,北部、东北部90年代以来呈明显减少迹象。(3)夏玉米在播种期、苗期、成熟期,各区域降水量无明显增加或减少的趋势。在拔节期、抽穗期,各区域降水量都表现为减少趋势,东北部减少趋势最明显,南部减少趋势最弱。(4)冬小麦不同发育期降水量变化趋势在各区域是一致的;而夏玉米不同发育期降水量在各区域存在相反的情况,即在同一年四个区域中有的偏多、有的偏少。

The features of temporal-spacial precipitation change during crop growth in Hebei province

Using the rainfall information in the different growing periods of winter wheat and summer corn from 80 weather stations in Hebei,the spatial and temporal distribution of rainfall variations were analyzed.the results show that(1) Nearly 50 years there was significant increase or decrease in precipitation in winter wheat growing season.In summer corn growing period the regional precipitation was linearly decreased,from the south to north the trend was clearly reduced.(2) During the period from sowing to emergence for winter wheat in central and southern area there was a growing trend in precipitation,the precipitation change in northeast was not obvious.Since the 90s the precipitation in north region was also increasing.In the tillering period,wintering period,turning green period,jointing period,maturity period,there were no significant precipitation changes.In the heading period,the precipitation showed a large range of fluctuations.In southern and central areas there were linear increasing trend of precipitation;In north and north-east areas there were significantly reduced signs since the 90s.(3)In the sowing period,seedling period and mature period of corn,precipitation showed no significant increase or decrease trends.In the jointing period,heading period,the all regional precipitation showed decreasing trend.(4)Precipitation trends were consistent in the all regions in different growing periods of winter wheat.But for summer corn at different developmental stages the regional precipitation existed opposite situation.