河北省近50年蒸发量气候变化特征

利用河北省68个气象站1956～2000年20cm口径蒸发皿资料,分析了河北省蒸发量的气候变化趋势。结果表明:近50a来,河北省平均蒸发量呈明显下降趋势,各气候分区变化趋势与全省相似;各季平均蒸发量的年际变化趋势与年值相似,春季下降幅度最大、夏季次之、冬季最小;全省及各分区平均蒸发量大部在60年代最大,60年代至90年代逐渐下降。蒸发量的下降原因与平均风速的减小存在明显正相关。

Change of Evaporation in Recent 50 Years in Hebei Region

Based on the available observation data of 1956～2000 from 68 meteorological stations in the Hebei region ,the evaporation changesin this area have been analyzed. The results show: In recent 50 years, the evaporation is declined remarkably in the Hebei region, and in different area of this region.The characteristics of the evaporation's variation in every senson are similar. The extentof change is maximumin spring, and minimun in winter. In 60's ,The evarage evaporation is maximum in the most of the Hebei region, and in different area. The evaporation is decreased from 60's to 90's.The reason of evaporation decline is directly correlatiedto the minish of evarage wind speed.