摘要
确定干湿条件变化的控制机制,将增进对近百年气候变化的认识,对乌兹别克斯坦干旱地区气候环境变化的研究具有重要意义.本研究基于乌兹别克斯坦东南部采集的25棵树的38个树芯样本,以土耳其斯坦圆柏(Juniperus turkestanica)为研究对象,建立了 1780～2014年的可靠年表,分析了研究区树轮宽度年表与月标准化降水蒸散指数(Standardized Precipitation Evapotranspiration Index,简称SPEI)之间的相关性,结果表明:在生长季,降水和气温是树木径向生长的主要限制因子,其中降水促进树木生长,气温则相反.标准年表(STD)与多月份组合气象因子相关分析,上年6月至当年5月平均SPEI与STD呈极显著正相关,相关性最大(R=0.643,P＜0.01).基于以上分析,建立了树轮宽度与SPEI6-5线性回归方程,方差解释量41.3％,P＜0.01.采用逐一剔除法检验发现,误差缩减(RE)值大于0,乘积平均数(PMT)为7.63,验证了重建的方程的可靠性和稳定性.重建了 1780～2014年SPEI6-5序列,在过去的235 a中,研究区经历了 8年极干旱年份,4年极湿润年份.研究区干湿变化主要受大气环流因子:太平洋多年代际震荡和北大西洋涛动等影响,本研究可为气候变化背景下乌兹别克斯坦东南部水资源的管理和科学合理的利用等提供数据参考.
Abstract
Determining the controlling mechanisms of drought and wet conditions will enhance our understanding of climate change over the past century and is of great significance for studying climate and environmental changes in the arid regions of Uzbekistan.This study is based on 38 tree core samples collected from 25 Juniperus turkestanica trees in southeastern Uzbekistan,establishing a reliable chronology from 1780 to 2014.It analyzes the correlation between the tree-ring width index of Juniperus turkestanica and the monthly Standardized Precipitation Evapotranspiration Index(SPEI)in the study area.The results indicate that during the growing season,precipitation and temperature are the main limiting factors for radial tree growth,with precipitation promoting growth and temperature inhibiting it.Correlation analysis between the standard chronology(STD)and combined meteorological factors of multiple months showed a highly significant correlation between the average SPEI from June of the previous year to May of the current year and the STD(R=0.643,P＜0.01).Based on this analysis,a linear regression model was established,explaining 41.3％of the variance.The reliability and stability of the reconstructed equation were validated using the leave-one-out method,with a reduction of error(RE)value greater than 0 and a product mean test(PMT)value of 7.63.The reconstructed SPEI6-5 sequence for 1780～2014 shows that the study area experienced 8 extremely dry years and 4 extremely wet years over the past 235 years.The drought and wet conditions in the study area may be influenced by atmospheric circulation factors,including the Interdecadal Pacific Oscillationt and the North Atlantic Oscillation,which regulate climate and hydrological changes through water vapor flux.This study provides data references for the management and scientific utilization of water resources in southeastern Uzbekistan in the context of climate change.
基金项目
新疆维吾尔自治区自然科学基金项目(2021D01B118)
国家自然科学基金国际合作项目(32061123008)
新疆维吾尔自治区重点实验室开放课题(2021D04004)
新疆维吾尔自治区重点实验室开放课题(2022D04005)
NETL
NSTL
万方数据