香港地区降水氢氧同位素多尺度演变特征分析  

Multi time scale variation of hydrogen and oxygen isotopes in precipitation under changing environment in Hong Kong area

作　　者：胡海英[1] 黄华茂[2] 杨健文[1] 

机构地区：[1]华南理工大学土木与交通学院,广东广州510640 [2]华南理工大学理学院,广东广州510640

出　　处：《武汉大学学报（工学版）》2014年第5期577-584,620,共9页Engineering Journal of Wuhan University

基　　金：国家自然科学基金项目(编号:51209096);水文水资源与水利工程科学国家重点实验室开放研究基金(编号:2011490411);中央高校基本科研业务费专项资金资助(编号:2013ZZ019)

摘　　要：以香港站1973-2008年大气降水稳定同位素与气象资料为基础,应用线性回归、Mann-Kendall趋势检验、小波分析和Spearman相关分析等多种方法,探讨了月、季和年等不同时间尺度下降水氢氧同位素序列的演变特征及其影响机制.结果表明：1多年月均降水氢氧同位素组成与月均降水量、温度和水汽压之间呈显著的负相关关系,表明存在明显的降水量效应,而不存在温度效应;2降水氢氧同位素组成的季节变化明显：雨季（5-10月）偏低,旱季（11-4月）偏高,具有典型的季风气候降水同位素变化特征;3年均降水氢氧同位素序列年际变化大,总体呈下降趋势,下降率分别为-0.08‰/a（D）和-0.01‰/a（18 O）,其变化趋势与年均降水量、温度、水汽压序列成相反关系,反映了降水同位素随长期气候变化的综合效应影响;4Morlet小波分析结果表明,年平均降水氢氧同位素序列存在4a、7-9a和16-22a等3类时间尺度的周期性变化规律,其中16-22a时间尺度表现最明显;5多年年均降水氘盈余值偏小,且没有明显的长期变化趋势.Variation of stable isotope in precipitation effected by meteorological factors,geographic parameters,and other hydrological factors,is a complex dynamic process,with highly nonlinear and multi time scale characteristics.This paper focuses on identifying variation in the stable isotopes in precipitation under changing environment.Based on the stable isotopic composition in precipitation and meteorologic data at Hong Kong station during 1973-2008,the regression analysis,Mann-Kendall,wavelet analysis and correlation analysis methods are used to find out the variation law of stable isotopic composition in precipitation under different time scales and its influencing factors.The results show that there is significant negative correlation between stable isotopic composition in monthly precipitation,temperature and vapor pressure.It indicates an obvious rainfall amount effect,but the temperature effect does not exist.Under seasonal scale,it displays obvious seasonal change that the stable isotopic compositions of precipitation in rainy season（May to October）,are more negative than those in dry season（November to April）.Under annual scale,the stable isotopic composition in annual mean precipitation changes greatly,and has a downward trend as a whole,which is contrary to those of rainfall,temperature and vapor pressure.The rates of decline are-0.08‰/year（D）and-0.01‰/year（18 O）respectively.Therefore,isotopic composition varia-tions in annual mean precipitation reflect the combined impact of long-term climate change.Moreover,deuterium excess of annual mean precipitation is small and has no obvious long-term trend,which indicates that the imbalance of evaporation and condensation in precipitation process is not significant;and the precipitation is mainly controlled by tropical storm.In addition,the results of continuous wavelet transform indicate that there are obvious periodic variations with scales 4a,7-9aand 16-22 afor the isotopic composition of annual mean precipitation series,and scale 16-22 ais th

关 键 词：降水 氢氧同位素 演变特征 影响因素 不同时间尺度 

分 类 号：P339[天文地球—水文科学]