1470年以来长江流域降水重建及其特征分析  

Precipitation reconstruction and its characteristics in the Yangtze River Basin since 1470

作　　者：许文锋 张乐满 范依捷 陈详乐 段晨辉 敦静怡 刘正学 兰波 Xu Wenfeng;Zhang Leman;Fan Yijie;Chen Xiangle;Duan Chenhui;Dun Jingyi;Liu Zhengxue;Lan Bo(College of Environmental and Chemical Engineering,Chongqing Three Gorges University,Chongqing 404100,China;Hechi Ecological Environment Monitoring Center,Hechi 547000,Guangxi,China;Center for Pan-third Pole Environment,Lanzhou University,Lanzhou 730000,Gansu,China)

机构地区：[1]重庆三峡学院环境与化学工程学院,重庆404100 [2]广西壮族自治区河池生态环境监测中心,广西河池547000 [3]兰州大学泛第三极环境中心,甘肃兰州730000

出　　处：《地理科学》2024年第11期2029-2038,共10页Scientia Geographica Sinica

基　　金：国家自然科学基金青年科学基金项目(41902024);重庆市科委面上项目(cstc2019jcyj-msxmX0656);重庆市教委青年项目(KJQN201801221);重庆三峡学院校人才引进项目(17RC08);重庆“三峡库区水环境演变与污染防治”重点实验室开放基金项目(WEPKL2019ZD-02);三峡库区可持续发展研究中心开放基金(18sxxyjd12)资助。

摘　　要：根据文献旱涝图集、树轮帕默尔干旱指数(PDSI)图集及GPCC降水数据集,本文重建中国长江流域1470—2000年的降水序列并探讨降水特征变化。长江流域现代器测降水通过旋转经验正交分解可分为5个降水区:长江源区(Ⅰ区)、川汉盆地区(Ⅱ区)、西南山地区(Ⅲ区)、鄂渝山地区(Ⅳ区)、东部平原区(Ⅴ区)。重建降水多元回归模型经检验评估效果较好(P<0.01),验证期(1951—2000年)内各区重建降水和实测降水具可比性(0.70<r<0.83,P<0.01),相对偏差介于±30%,重建无明显偏好。各区重建降水在1470—1540年、1660—1705年湿润事件偏多。西、北部的Ⅰ、Ⅱ区降水趋同变化(r=0.27,P<0.01),Ⅰ区、Ⅱ区降水分别在1935—1985年、1845—1950年出现更多洪涝事件。Ⅲ区降水在1620—1655年、1933—1945年、1986—1994年出现显著干旱。Ⅵ区和Ⅴ区降水显著正相关(r=0.47,P<0.01)。长江流域各区降水存在多个2~7 a的显著短周期。此外,Ⅰ区降水出现9 a、31~51 a的中长周期;Ⅱ区出现22 a、约36 a和256 a的中长周期;Ⅳ区存在约21 a周期;Ⅴ区存在256 a的长周期。According to Drought and Flood Atlas(DFA)based on bibliography,tree-ring reconstructed Palmer drought severity index(PDSI)and GPCC precipitation dataset,5 precipitation sequences in the Yangtze River Basin(YRB)of China have been reconstructed from 1470 to 2020,and the precipitation characteristics was discussed further.Spatially,the YRB can be divided into 5 precipitation sub-regions based on modern meteorological precipitation,namely:the source region of the Yangtze River(RegionⅠ),the Sichuan-Han basin region(RegionⅡ),the southwest mountainous region(RegionⅢ),the Hubei-Chongqing mountainous region(RegionⅣ)and the eastern plain region(RegionⅤ).Significant negative correlations between DFA and the adjacent tree ring reconstructed PDSI in each sub-region have been detected(P<0.01),establishing the basis for the extraction of precipitation information.The R2 of reconstructed precipitation by multiple regression model ranged from 0.16 to 0.68(P<0.01),and has been further evaluated by effective coefficient,relative deviation(RD),showing that the model was acceptable.The reconstructed precipitation was well comparable to the measured precipitation during the verification period(1951—2000)(0.70<r<0.83,P<0.01).The RD varied between±30%without obvious bias.More wet events occurred during 1470—1540 and 1660—1705.The precipitation in RegionⅠandⅡchanged synchronously(r=0.27,P<0.01),with more flood events during 1935—1985 for RegionⅠand during 1845—1950 for RegionⅡ,respectively.The precipitation in regionⅢwas significant drought at the intervals of 1620—1655,1933—1945 and 1986—1994.The precipitation in RegionⅣandⅤhighly correlated(r=0.47,P<0.01).Several short periodicities of precipitation(2-7 a)revealed by multi-taper method of periodicity analysis in the YRB have been obtained.In addition,there were additional periodicities for precipitation in each region,that is,9 a,31-51 a in RegionⅠ;22 a,36 a and 256 a in RegionⅡ;about 21 a in RegionⅣ;about 256 a in RegionⅤ.

关 键 词：长江流域 REOF分区 降水重建 降水周期分析 

分 类 号：P467[天文地球—大气科学及气象学]