摘要
以石羊河流域5个气象站从建站到2008年逐月降水量资料为基础,从mann-kendall方法入手,分析了降水量的时间和空间变化特征。结果表明:石羊河流域降水量变化存在地理差异,上游明显减少(Zc=-0.561),中游略有增加,下游略有减少。流域年降水量呈波动性变化,在近十年间流域的增湿非常明显,气候变化趋于暖湿性。年内降水量分布极不均匀,8月份降水量极不稳定,季节性降水差异明显。此外上下游降水分别存在准17 a、准9 a的周期震荡,而中游则同时兼顾这两种主周期变化。降水量在空间分布上由南向北递减,形成"乌鞘岭>古浪>永昌>武威>民勤"的降水递减变化特征。
The spatio-temporal characteristics of precipitation were analyzed in the Shiyang River Basin, Gansu Province, China, on the basis of monthly precipitation dada collected at 5 meteorological stations from their foundation to 2008 and by means of Mann - Kendall method. The results show that the variation in precipitation is characterized by regional difference. It means that the precipitation in upper reaches decreases obviously（ Zc = -0. 561 ）, a little increases in the middle reaches and a little decreases in the lower reaches. The annual precipitation is with wave-shaped variation, and during last 10 years the phenomena of air moisture increasing was obvious and the meteorological change tended to warming-wetting. The annual precipitation was not even extremely with unstable precipitation in August to the utmost and obvious differential between seasonal precipitations. In addition, there were quasi-17 years＇ and quasi-9 years＇ periodical vibration for upper reaches precipitation and lower reaches precipitation, respectively with the middle reaches＇ precipitation having this kind of two main periodical variations. As for spatial distribution of precipitation, it gradually decreases from south to north, resulting in following precipitation ranking in quantity： Wushao Ridge＇s precipitation 〉 Gulang ＇s 〉 Yongchang＇s 〉 Wuwei＇s 〉 Minqin＇s
出处
《干旱区地理》
CSCD
北大核心
2010年第4期593-599,共7页
Arid Land Geography
基金
公益性行业(气象)科研专项:西北地区旱作农业对气候变暖的响应特征及其预警和应对技术研究(GYHY200806021)
