中国西北极端降水事件年内非均匀性特征分析  

Analysis on Inner-annual Inhomogeneity Characteristic of Extreme Precipitation Events over Northwest China

作　　者：杨金虎[1] 江志红[2] 王鹏祥[1] 张小明 

机构地区：[1]中国气象局兰州干旱气象研究所/甘肃省干旱气候变化与减灾重点实验室/中国气象局干旱气候变化与减灾重点开放实验室 [2]江苏省气象灾害重点实验室(南京信息工程大学),江苏南京210044 [3]甘肃省定西市气象局,甘肃定西743000

出　　处：《中国沙漠》2008年第1期178-184,共7页Journal of Desert Research

基　　金：中国气象局成都高原气象开放实验室基金项目(LPM2007002);干旱气象科学研究基金项目(IAM200609)共同资助

摘　　要：基于中国西北五省(区)1960—2004年112个台站逐日降水资料,根据百分位值方法定义了不同台站的极端降水阈值,引入了表征时间分配特征的新参数——极端降水事件集中度和集中期,对中国西北极端降水事件的年内非均匀性特征进行了分析,结果表明:西北年极端降水事件集中度及集中期的平均和异常空间分布都存在很大的区域差异,并且其异常空间分布均可分为6个关键区;而从时间演变来看,各个关键区年极端降水事件的集中度与集中期均表现出了显著的年代际振荡特征,但各分区年代际变化特征并不一致;另外西北东、西部年极端降水事件集中度与集中期表现出反向的变化趋势。Based on the daily precipitation datasets from 1960 to 2004 recorded at the 112 stations in the five provinces of northwest China, the extreme precipitation threshold of different stations were defined by centesimal value method, the inner-annual inhomogeneity characteristics of extreme precipitation events were analyzed by introducing the new parameters that reflect the temporal distribution of extreme precipitation events：concentration degree（ECD） and concentration period（ECP）. The result showed that the average and anomalous spatial distributions of ECD and ECP all existed obvious spatial difference in northwest China, and their anomalous spatial distribution all can be divided into six key areas, namely the north Xinjiang area, the loess plateau and Ningxia plain area, the Qaidam Basin and Hexi Corridor area, the south Xinjiang area, the south Qinghai plateau area, and the Qinba mountainous area. As for temporal distribution of extreme precipitation events, the ECD and ECP all existed remarkable inter-decadal vibration in these six key areas, but their distribution characteristic was inconsistent. Besides, the change tendency was inversed between in the east and in the west of the northwest China.

关 键 词：中国西北 极端降水事件 年内非均匀性 

分 类 号：P468.024[天文地球—大气科学及气象学]