河西走廊干旱区农业气候资源变化特征

以1960~2005年河西走廊地区19个气象站46年的气候资料为基础,运用气候变化倾向率方法对该地区年及春、夏、秋、冬四季的光、热、水等主要农业气候资源要素进行诊断分析,并应用Mann-Kendall方法对主要农业气候资源要素的突变性进行了检测和分析。结果表明,近46年来,河西走廊区域内的气温呈平缓上升趋势,热量资源比较丰富,特别是平均最低气温增温幅度明显,冬季增温大于春、夏、秋季,但总体增温幅度低于我国平均增温水平,温度等热量资源在20世纪90年代中期同步发生突变。降水量变化比较平缓,呈略有增加的趋势,且季节性明显,夏季降水增加的贡献最大,与降水有密切关系的蒸发潜力自60年代起一直呈上升趋势,并在90年代中期发生突变,增速加快,降水蒸发差从70年代起呈缓慢下降趋势,不存在突变现象。太阳辐射与日照时数变化趋势一致,总体呈上升趋势,变化倾向率均为正值,从地域分布上看,北部及中部走廊绿洲区数值增加明显。河西走廊区域内总体的农业气候变化以"气温升高,降水略增、日照增加"为主要特点。文章最后简要分析讨论了农业气候资源的变化给河西走廊农业生产带来的主要影响。

Characteristics of agricultural climate resources' changing in dry area of Hexi corridor

According to the climate data observed by 19 weather stations in Hexi corridor from 1960 to 2005,the annual and seasonal agricultural climate resources,including light,heat and water and so on,are diagnostically analyzed by using the method of climate changing tendency,and the abrupt changes of critically agricultural resources factors are analyzed by approach of Mann-Kendall.The research reveals that,in recent 46 years,the temperature in Hexi corridor rose smoothly thereby abundant heat resources,especially average minimum temperature rose obviously;the increasing amplitude of winter is larger than that of other seasons;however,the gross increasing amplitude is lower than the average level of whole China;the heat resources abruptly changed in 1990s'.The amount of precipitation varied gently,while tending to slightly increase and relating obviously to seasons-the increase of summer precipitation contributes remarkably.Since 1960s',vaporizing potential,close relating to the precipitation,tended to ascend,and abruptly changed to rapidly increase;the difference between precipitation and vaporization decreased slowly since 1970s' without abrupt change.The solar radioactivity and sunshine hours tend identically to increase and their various tendencies are all positive;from aspects of regional distribution,the number of oasis in north and middle of the corridor increased dramatically.The total agricultural climate changing-characteristics include temperature's rising,precipitation's slightly increasing,and sunshine hours' increasing.Finally,the chief influence brought by the change of agricultural climate resources to agricultural production in Hexi corridor is discussed and analyzed.