中文摘要：

采用松嫩平原西部34个气象站1951～2000年5个气象要素资料．运用FAO Penman—Monteith方程计算参考作物蒸散量．建立了各站与区域蒸散量序列。运用气候数理统计方法对蒸散量序列时空变化特征进行诊断分析．并以点、面相结合的方式揭示气候突变规律。结果表明，蒸散量基本上以西南部沙地为高值中心向东北呈带状递减：近50年区域蒸散量略呈增加趋势．研究区北部的蒸散量增加贡献最大：区域蒸散量以1962和1982年为转折点．呈明显的阶段性变化；在50年的演变过程中．区域蒸散量被检测到2次增加突变和1次减少突变．典型站突变发生时间与区域突变基本相符．但突变性质存在明显的地域差异。

英文摘要：

Reference crop evapotranspiration （ETo） is one of important climate factors, mainly affected by local climate. As related to water balance and energy balance, it decides the shaping and evolvement of geographical environment. With 34 meteorological stations＇ data including minimum and maximum air temperature, wind speed, air humidity and sunlight hours from 1951 to 2000, ETo was obtained by FAO Penman-Monteith equation （P-M） for growing season in western Songnen Plain of Northeast China. Then the authors analyzed the temporal-spatial characteristics of ETo series with climate diagnostic analysis, and the abrupt change points through point-area integrated analyses by Jr parameter and Mann-Kendall methods. The results show that： （i） the high value of ETo appears in southwest sandy land, and ETo gradually decreases northeastwards; （ii） ETo tends to increase in recent 50 years, and the north area contributes most; （iii） taking 1962 and 1982 as turning points, areal ETo series indicates evident phase changes during period of 1951-2000; and （iv） two upward and one downward abrupt changes are examined in areal ETo series, and the time of abrupt changes in typical stations is basically consistent with that in study area, but properties of abrupt changes show evident spatial diversity.