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Water discharge variability of Changjiang(Yangtze) and Huanghe(Yellow) Rivers and its response to climatic changes

Chinese Journal of Oceanology and Limnology 2014年第6期32卷 1392-1405页

作者：张喜林范德江王厚杰杨作升 Key Laboratory of Submarine Geosciences and Technology of Ministry of Education Ocean University of China Key Laboratory of Marine Hydrocarbon Resources and Environment Geology China Geological SurveyMinistry of Land and Resources Qingdao Institute of Marine Geology China Geological Survey

Influences of large-scale climatic phenomena, such as the E1Nifio/La Nifia-Southem Oscillation （ENSO） and the Pacific Decadal Oscillation （PDO）, on the temporal variations of the annual water discharge at the Lijin station in the Huanghe （Yellow） River and at the Datong station in the Changjiang （Yangtze） River were examined. Using the empirical mode decomposition-maximum entropy spectral analysis （EMD- MESA） method, the 2- to 3-year, 8- to 14-year, and 23-year cyclical variations of the annual water discharge at the two stations were discovered. Based on the analysis results, the hydrological time series on the inter- annual to interdecadal scales were constructed. The results indicate that from 1950 to 2011, a significant downward trend occurred in the natural annual water discharge in Huanghe River. However, the changes in water discharge in Changjiang River basin exhibited a slightly upward trend. It indicated that the changes in the river discharge in the Huanghe basin were driven primarily by precipitation. Other factors, such as the precipitation over the Changjiang River tributaries, ice melt and evaporation contributed much more to the increase in the Changjiang River basin. Especially, the impacts of the inter-annual and inter-decadal climate oscillations such as ENSO and PDO could change the long-term patterns of precipitation over the basins of the two major rivers. Generally, low amounts of basin-wide precipitation on interannual to interdecadal scales over the two rivers corresponded to most of the warm ENSO events and the warm phases of the PDO, and vice versa. The positive phases of the PDO and ENSO could lead to reduced precipitation and consequently affect the long-term scale water discharges at the two rivers.

关键词： water discharge Changjiang (Yangtze) River Huanghe (Yellow) River empirical modedecomposition maximum entropy spectral analysis large-scale climate factor

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A grey model with periodic term for sea-level analysis and its application to the Guangxi coast

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Acta Oceanologica Sinica 1999年第3期18卷 325-335页

作者：夏华永李树华 Guangxi Mar. Monitoring Forecast. C. Beihai 536000 China

A grey model with periodic term for sea-level analysis is *** present model keeps some advantages of tea GM (1, 1 )model, which well reflects the trend of sea-level changes and gives out the change rate as well as the acceleration of sea level *** *** addition, the present model can reproduce the periodic phenomena of sealevel, hence, it overcomes the shortcomings of the GM(1,1) model that is unsuitable for forecasting monthly mean sealevel with apparent periodicity, and its prediction accuracy is *** present model is used to analyse Guangxi coast sea level,the results show that the rise rates of relative sea level at Beihai, Weizhou and Bailongwei are 1 .67,2 .51 and 0.89 mm/a respectively, the relative sea level at Shitoubu has a falling trend with a rate of 0. 5- 1 .0 mm/a, the rise rate of eustatic sea level along the Guangxi coast is 2 .0 mm/a. In comparison with the model with a lineartrend term plus a periodic term, the simulation accuracies of both models are about the same.

关键词： Grey model periodic term monthly mena sea level maximum entropy spectral analysis

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AR滤波器方法在低纬哨声处理中的尝试

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地球物理学报 1988年第5期 601-605页

作者：赵正予唐存琛保宗悌梁百先武汉大学空间物理系

高纬与低纬哨声的主要区别表现在信号持续时间和强度上。在低纬地带,哨声持续时间通常较短,其强度要比高纬哨声弱,因此,其信噪比也较低。如何处理和分析低纬哨声信号,从高噪声背景中抽取有用信息,一直是很重要的课题。传统的傅里叶变... 详细信息

高纬与低纬哨声的主要区别表现在信号持续时间和强度上。在低纬地带,哨声持续时间通常较短,其强度要比高纬哨声弱,因此,其信噪比也较低。如何处理和分析低纬哨声信号,从高噪声背景中抽取有用信息,一直是很重要的课题。传统的傅里叶变换方法,即非参数估值方法,虽然简便、陕捷,但由于这种方法仅仅利

关键词： Low latitude whistler maximum entropy spectral analysis AR filter spectral resolution.

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