1960-2005年澜沧江流域极端降水变化特征  

Changes in Precipitation Extremes in Lancang River Basin,1960-2005

作　　者：李斌[1,2] 李丽娟[1] 李海滨[3] 梁丽乔[1] 李九一[1,2] 柳玉梅[1,2] 曾宏伟[1,2] 

机构地区：[1]中国科学院地理科学与资源研究所,北京100101 [2]中国科学院研究生院,北京100049 [3]普林斯顿大学,新泽西州08540

出　　处：《地理科学进展》2011年第3期290-298,共9页Progress in Geography

基　　金：科技部科技基础性工作专项(2008FY110300-01);欧盟第六框架项目(SWITCH-018530)

摘　　要：极端降水事件是气候变化的一个重要方面。澜沧江流域纵贯13个纬度,最大相对高差近5000 m,跨6种气候带,是全球少见的南北向大江,它在气候、水文、地理、生态学等多方面都具有重要的科学研究价值。自1960年以来,流域经历了显著的气温上升。探讨在气候变暖背景下这一复杂流域的极端降水变化具有重要意义。本文利用澜沧江流域及其周边35个气象站1961-2005年的日降水资料,分析了小于5 mm、5～10 mm、10～50 mm以及大于50 mm 4个不同量级降水的降水量、降水日数和日平均降水强度的变化趋势。并计算了每种量级降水占总降水量的百分比及降水频率。结果表明,各量级各项指标均存在明显的区域变化特征,流域总体上极端降水频率的增加态势明显。对典型地区站点分析表明,极端降水的增加可能与气候系统随机性变强有关。Extreme precipitation is an important aspect of climate change. According to the estimation using the latest climate models, the extreme precipitation events will become frequent in a warming world. Significant increases of the very heavy precipitation and decreases of light and moderate precipitations have indeed been ob- served over most land areas of the globe in the last few decades. The Lancang River, with a relative altitude dif- ference of about 5000 m, flows through 13 latitudes and 6 climatic zones. It is rarely seen in the world and has important scientific values for climatology, hydrology, geography and ecology. Since 1960, the basin has experienced a significant increase in temperature like most parts of the world. Studying the changes of extreme precipi- tation events in the basin in the context of global warming is of great importance. Based on a daily precipitation dataset of 35 meteorological observation stations distributed in and around the Lancang River basin, trends of precipitation amounts, precipitation days and daily precipitation intensity dur- ing a 45-year period （1961-2005） of 4 different classes ranging from less than 5, 5-10, 10-50 and larger than 50 mm were analyzed, and the precipitation frequency and the proportion of precipitation amount of each precipita- tion class were calculated. The result showed that all the indexes varied spatially, and for the basin as a whole, the frequency of the extreme events increased obviously. Analysis of a typical station indicated that the increase of extreme precipitation and the randomness of the climatic system might be closely related with each other.

关 键 词：降水 强度 趋势 澜沧江流域 

分 类 号：P468.024[天文地球—大气科学及气象学]