黑龙江省近50年干旱发展事实及分析

Arid Climate Trend over Heilongjian Its Province for the Past 50 Years

应用实测的降水、气温和土壤湿度资料,分析黑龙江省近50年干旱化的发展趋势。结果表明,用月平均气温、降水量距平和均方差所构造的“干旱指数”以及土壤湿度显示近50年来黑龙江省是向干旱发展的。1990年以来这种干旱化趋势尤为明显,西部亚干旱地区的干旱化相对更严重。在气温和降水两个要素中,气温的升高对干旱化的作用可能更重要。利用NCEP/NCAR的容积式土壤湿度计算了全球50年来干旱的发展趋势,结果表明:黑龙江省近50年干旱的发展是全球气候异常的重要组成部分。这显然与全球气候变暖的大背景有关。为探讨东北区干旱的发展对全球气候变暖的响应,利用Jones等的1951～2000年全球平均气温资料和黑龙江省10个站的干旱指数进行线性回归分析。结果表明:在全球平均温度上升1℃的情况下,黑龙江省的干旱化程度要增加10%左右。这种形势应该引起我们的关注。

The station data including precipitation,air temperature and soil humi dity are employed to investigate the arid climate trend for the past 50years over Hei Longjiang province .'drought indexis proposed based on monthly mean temperature and precip itation anomalies as well as mean variance.The variations in the index an d soil humidity show that the arid situ ation gets deteriorated all over Hei Longjiang province,this arid trend is more significant since the middle of 1990's.Air temperature increase plays more important role than precipitation de-crease does,It is obviously associated with glob al warming.The responses of develop ing aridity over Hei Longjiang province to the global warming are ex plored using linear regression analyses.The results show that under cir-cumstance of global temperature increase 1℃,the aridity extent will add around 10%.