The Analysis of the Characteristics of Annual Runoff Series through Wavelet Coefficients

2010 ◽  
Vol 113-116 ◽  
pp. 575-578
Author(s):  
Su Yi Liu
Keyword(s):  
Time Series ◽  
Wavelet Transform ◽  
Yangtze River ◽  
Yellow River ◽  
Annual Runoff ◽  
Wavelet Function ◽  
Wavelet Coefficients ◽  
Precipitation Time Series ◽  
Monthly Data ◽  
Runoff Series

A runoff-sequence contains many frequencies, from the point of the wavelet transfor- mation, they are included in different wavelet coefficients. Therefore, when a smooth wavelet function is used, changes in multi-time scale and jump characteristics of precipitation time series have been probed the tendency. Wavelet transform can clearly demonstrate all kinds of characteristics of precipitation runoff series: the strength and distribution of time scales. The monthly data used in this paper comes from Guidei hydrology station of Yellow River (1919-1994) and Yichang hydrology station of Yangtze River (1946-1976), and the yearly ones from Yichang hydrology station (1882-1984).

Periodic Change of River Runoff Based on EMD-MES

2011 ◽  
Vol 250-253 ◽  
pp. 2848-2851
Author(s):  
Xue Hua Zhao ◽  
Li Li An
Keyword(s):  
Time Series ◽  
Maximum Entropy ◽  
Yellow River ◽  
Annual Runoff ◽  
Scientific Data ◽  
Entropy Spectrum ◽  
Mode Decomposition ◽  
Periodic Analysis ◽  
Runoff Series ◽  
Maximum Entropy Spectrum

This paper discusses stabilizing treatment of runoff time series by empirical mode decomposition (EMD), and periodic analysis of stabilized runoff time series by maximum entropy spectrum, and presents high-resolution character of maximum entropy spectrum and its application prospect in hydrology. It conducts the analysis and calculation in combination with a real example of annual runoff series at the Lanzhou station in the upper of Yellow River, and study proves that annual runoff has 11.1, 6.25 and 3.1 years significant periods at the Lanzhou station. The conclusion illustrates the feasibility of this method and provides scientific data for water resources planning and managing.

Analysis on the Process of Flow-Sediment in Jianli Reach of Yangtze River before and after the Construction of Three Gorges Project

2012 ◽  
Vol 212-213 ◽  
pp. 230-235
Author(s):  
Xiao Fang Liu ◽  
He Qing Huang ◽  
Cai Yun Deng
Keyword(s):  
Time Series ◽  
Change Point ◽  
Hurst Exponent ◽  
Yangtze River ◽  
Abrupt Change ◽  
Sediment Load ◽  
Kendall Test ◽  
Annual Runoff ◽  
Runoff Series ◽  
Anomaly Analysis

Jianli Reach has long been exposed to labile main flow and the frequent translocation between the main channel and the lateral branch. To investigate how the long-term process of flow-sediment influences the adjustment of river channel pattern, monthly time series (1951-2009) of runoff and sediment load at Jianli hydrological station of Yangtze River were analyzed using three methods: R/S analysis to estimate Hurst exponent, Mann-Kendall method and the time series anomaly analysis. The result shows that on 1 year time scale, the values of Hurst exponent are indicating persistence, that is to say, the trend of runoff and sediment in the future will generally be the same as the past, and the persistence in runoff series is stronger than that in the sediment load. The period of oscillation in annual runoff and in sediment load is about 30 years. The result of Mann-Kendall test shows an abrupt change point of runoff time-series at 1967 and an abrupt change point of sediment load time-series at 2003. And during the flood season, the values of Hurst exponent still indicate persistence, which is weaker than that in whole year correspondingly.

Application of MEEMD-ARIMA combining model for annual runoff prediction in the Lower Yellow River

2019 ◽  
Vol 11 (3) ◽  
pp. 865-876 ◽  
Author(s):  
Xianqi Zhang ◽  
Wei Tuo ◽  
Chao Song
Keyword(s):  
Time Series ◽  
Empirical Mode Decomposition ◽  
Yellow River ◽  
Arima Model ◽  
Ensemble Empirical Mode Decomposition ◽  
Annual Runoff ◽  
Lower Yellow River ◽  
The Lower Yellow River ◽  
Mode Decomposition ◽  
Runoff Prediction

Abstract The prediction of annual runoff in the Lower Yellow River can provide an important theoretical basis for effective reservoir management, flood control and disaster reduction, river and beach management, rational utilization of regional water and sediment resources. To solve this problem and improve the prediction accuracy, permutation entropy (PE) was used to extract the pseudo-components of modified ensemble empirical mode decomposition (MEEMD) to decompose time series to reduce the non-stationarity of time series. However, the pseudo-component was disordered and difficult to predict, therefore, the pseudo-component was decomposed by ensemble empirical mode decomposition (EEMD). Then, intrinsic mode functions (IMFs) and trend were predicted by autoregressive integrated moving average (ARIMA) which has strong ability of approximation to stationary series. A new coupling model based on MEEMD-ARIMA was constructed and applied to runoff prediction in the Lower Yellow River. The results showed that the model had higher accuracy and was superior to the CEEMD-ARIMA model or EEMD-ARIMA model. Therefore, it can provide a new idea and method for annual runoff prediction.

scholarly journals Advantages Of A Time Series Analysis Using Wavelet Transform As Compared With A Fourier Analysis

2015 ◽  
Vol 23 (2) ◽  
pp. 30-36 ◽  
Author(s):  
Patrik Sleziak ◽  
Kamila Hlavčová ◽  
Ján Szolgay
Keyword(s):  
Time Series ◽  
Wavelet Transform ◽  
Time Series Analysis ◽  
Fourier Analysis ◽  
Stationary Time Series ◽  
Precipitation Time Series ◽  
Software Environment ◽  
R Software ◽  
Series Analysis ◽  
Average Annual Precipitation

Abstract The paper presents an analysis of changes in the structure of the average annual discharges, average annual air temperature, and average annual precipitation time series in Slovakia. Three time series with lengths of observation from 1961 to 2006 were analyzed. An introduction to spectral analysis with Fourier analysis (FA) is given. This method is used to determine significant periods of a time series. Later in this article a description of a wavelet transform (WT) is reviewed. This method is able to work with non-stationary time series and detect when significant periods are presented. Subsequently, models for the detection of potential changes in the structure of the time series analyzed were created with the aim of capturing changes in the cyclical components and the multiannual variability of the time series selected for Slovakia. Finally, some of the comparisons of the time series analyzed are discussed. The aim of the paper is to show the advantages of time series analysis using WT compared with FT. The results were processed in the R software environment.

scholarly journals A multiscale time-space approach to analyze and categorize the precipitation fluctuation based on the wavelet transform and information theory concept

2018 ◽  
Vol 49 (3) ◽  
pp. 724-743 ◽  
Author(s):  
Kiyoumars Roushangar ◽  
Vahid Nourani ◽  
Farhad Alizadeh
Keyword(s):  
Time Series ◽  
Wavelet Transform ◽  
Multiple Scales ◽  
Multiscale Entropy ◽  
Discrete Wavelet ◽  
Monthly Precipitation ◽  
Precipitation Time Series ◽  
Rain Gauges ◽  
Time Space ◽  
Precipitation Variation

AbstractThe present study proposed a time-space framework using discrete wavelet transform-based multiscale entropy (DWE) approach to analyze and spatially categorize the precipitation variation in Iran. To this end, historical monthly precipitation time series during 1960–2010 from 31 rain gauges were used in this study. First, wavelet-based de-noising approach was applied to diminish the effect of noise in precipitation time series which may affect the entropy values. Next, Daubechies (db) mother wavelets (db5–db10) were used to decompose the precipitation time series. Subsequently, entropy concept was applied to the sub-series to measure the uncertainty and disorderliness at multiple scales. According to the pattern of entropy across scales, each cluster was assigned an entropy signature that provided an estimation of the entropy pattern of precipitation in each cluster. Spatial categorization of rain gauges was performed using DWE values as input data to k-means and self-organizing map (SOM) clustering techniques. According to evaluation criteria, it was proved that k-means with clustering number equal to 5 with Silhouette coefficient=0.33, Davis–Bouldin=1.18 and Dunn index=1.52 performed better in determining homogenous areas. Finally, investigating spatial structure of precipitation variation revealed that the DWE had a decreasing and increasing relationship with longitude and latitude, respectively, in Iran.

Detection of Rainfall and Runoff Trends of the Adda River in Lecco (1845-2014) at Different Time Scales

10.29007/gbqh ◽  
2018 ◽  
Author(s):  
Roberto Ranzi ◽  
Massimo Tomirotti ◽  
Michele Brunetti ◽  
Alice Crespi ◽  
Maurizio Maugeri
Keyword(s):  
Time Series ◽  
Time Scales ◽  
Statistical Tests ◽  
Annual Runoff ◽  
Water Levels ◽  
Cycle Period ◽  
Catchment Scale ◽  
Significance Level ◽  
Runoff Series ◽  
Different Time Scales

A recovery of ancient records of the Como Lake water levels at the Fortilizio in Lecco hydrometric station enabled the reconstruction of a time series of daily water level and runoff from the Como Lake spanning the 1845-2014 period. In parallel, the monthly areal precipitation at the Adda river catchment scale was estimated for the same 170 years- long period. This time series, which is one of the longest available for Italian riverbasins will support analyses of the reasons of changes in the runoff regime in response to climatic and anthropogenic changes. A comparison of the two series applying the Mann- Kendall, Spearman and Theil-Sen trend tests, shows a decline, in the long term, of runoff and a more significant one of precipitation. Because some changes in the operation at the outlet of the Como Lake occurred after 1946 and also in the storage capacity of the upstream reservoirs the time series was splitted in two periods, before and after 1946. The results of the statistical tests for both precipitation and runoff in three time periods are consistent, but only for the time series of annual runoff the decline is statistically significant with 5% significance level. To analyse if changes occurred at different time scales the wavelet transform was applied to the daily runoff series. Finally the Fourier power spectrum of the the daily runoff data shows a signal of higher energy corresponding to a period between 11 and 13 years, close to the sunspots cycle period, and its significance is under investigation.

Climate Change of Tibetan Plateau and its Impact on Water Resources of the Source Region of Yangtze River and Yellow River in the next 30~50 Years

2010 ◽  
Vol 171-172 ◽  
pp. 547-550
Author(s):  
Zhi Gang Cheng ◽  
Guang Zhou Fan
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Yangtze River ◽  
Large Scale ◽  
Yellow River ◽  
Source Region ◽  
Annual Runoff ◽  
Climate Data ◽  
Average Annual Runoff ◽  
The Future

Based on high resolution dynamic downscaling meteorological forcing data, climate change of Tibetan Plateau and possible trends in runoff of the source region of Yangtze River and Yellow River were analyzed by using large-scale distributed hydrology model under future climate warming. The average annual runoff of the source region of Yangtze River and Yellow River will increase by 8.58% and 9.19% in the future 30 to 50 years. Although the annual precipitation will increase up to 4.48%, the average annual runoff of the source of Yellow River will reduce only by 1.98% in the next 30 to 50 years. The variations of runoff in the source area of Yangtze River and Yellow River are analyzed by using the climate data projected for the future 30 to 50 years and the scenario simulations of the land use/cover change. These results indicate that the runoff is the minimum (maximum) at forest land (bare land).

scholarly journals Possible Linkages of Hydrological Variables to Ocean–Atmosphere Signals and Sunspot Activity in the Upstream Yangtze River Basin

Atmosphere ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1361
Author(s):  
Ruting Yang ◽  
Bing Xing
Keyword(s):  
Time Series ◽  
Wavelet Transform ◽  
River Basin ◽  
Yangtze River ◽  
Yangtze River Basin ◽  
Spatiotemporal Variability ◽  
Sunspot Activity ◽  
Monthly Precipitation ◽  
Time Frequency ◽  
Hydrological Variables

Profiling the hydrological response of watershed precipitation and streamflow to large-scale circulation patterns and astronomical factors provides novel information into the scientific management and prediction of regional water resources. Possible contacts of El Niño–Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), sunspot activity to precipitation and streamflow in the upper Yangtze River basin (UYRB) were investigated in this work. Monthly precipitation and streamflow were utilized as well as contemporaneous same-scale teleconnections time series spanning a total of 70 years from 1951 to 2020 in precipitation and 121 years from 1900 to 2020 in streamflow. The principal component analysis (PCA) method was applied so as to characterize the dominant variability patterns over UYRB precipitation time series, with the temporal variability of first two modes explaining more than 80% of total variance. Long-term evolutionary pattern and periodic variation characteristics of precipitation and streamflow are explored by applying continuous wavelet transform (CWT), cross-wavelet transform (XWT) and wavelet coherence (WTC), analyzing multi-scale correlation between hydrological variables and teleconnections in the time-frequency domain. The results manifest that ENSO exhibits multiple interannual period resonance with precipitation and streamflow, while correlations are unstable in time and phase. PDO and sunspot effects on precipitation and streamflow at interannual scales vary with time-frequency domains, yet significant differences are exhibited in their effects at interdecadal scales. PDO exhibits a steady negative correlation with streamflow on interdecadal scales of approximately 10 years, while the effect of sunspot on streamflow exhibits extremely steady positive correlation on longer interdecadal scales of approximately 36 years. Analysis reveals that both PDO and sunspot have significantly stronger effects on streamflow variability than precipitation, which might be associated with the high spatiotemporal variability of precipitation.

scholarly journals Impact of the operation of cascade reservoirs in upper Yangtze River on hydrological variability of the mainstream

2018 ◽  
Vol 379 ◽  
pp. 421-432
Author(s):  
Xu Changjiang ◽  
Zhang Dongdong
Keyword(s):  
Yangtze River ◽  
Annual Runoff ◽  
Practical Significance ◽  
Efficient Operation ◽  
Cascade Reservoirs ◽  
Hydrological Variability ◽  
Upper Yangtze River ◽  
Runoff Series ◽  
The Impact ◽  
Hydrological Station

Abstract. As the impacts by climate changes and human activities are intensified, variability may occur in river's annual runoff as well as flood and low water characteristics. In order to understand the characteristics of variability in hydrological series, diagnosis and identification must be conducted specific to the variability of hydrological series, i.e., whether there was variability and where the variability began to occur. In this paper, the mainstream of Yangtze River was taken as the object of study. A model was established to simulate the impounding and operation of upstream cascade reservoirs so as to obtain the runoff of downstream hydrological control stations after the regulation by upstream reservoirs in different level years. The Range of Variability Approach was utilized to analyze the impact of the operation of upstream reservoirs on the variability of downstream. The results indicated that the overall hydrologic alterations of Yichang hydrological station in 2010 level year, 2015 level year and the forward level year were 68.4, 72.5 and 74.3 % respectively, belonging to high alteration in all three level years. The runoff series of mainstream hydrological stations presented variability in different degrees, where the runoff series of the four hydrological stations including Xiangjiaba, Gaochang and Wulong belonged to high alteration in the three level years; and the runoff series of Beibei hydrological station in 2010 level year belonged to medium alteration, and high alteration in 2015 level year and the forward level year. The study on the impact of the operation of cascade reservoirs in Upper Yangtze River on hydrological variability of the mainstream had important practical significance on the sustainable utilization of water resources, disaster prevention and mitigation, safe and efficient operation and management of water conservancy projects and stable development of the economic society.

Annual runoff change in the headstream of Yangtze River and its relation to precipitation and air temperature

2012 ◽  
Vol 44 (5) ◽  
pp. 850-874 ◽  
Author(s):  
Lihua Xiong ◽  
Kunxia Yu ◽  
Honggang Zhang ◽  
Liping Zhang
Keyword(s):  
Air Temperature ◽  
Yangtze River ◽  
River Flow ◽  
Annual Runoff ◽  
Climatic Conditions ◽  
The Yangtze River ◽  
Runoff Generation ◽  
Runoff Change ◽  
Runoff Series ◽  
Seasonal Analysis

We analyse the change trends of the annual and seasonal runoff series of the hydrological station Batang on the headstream of the Yangtze River over the period 1960–2007. The relations between runoff series and precipitation and temperature conditions are investigated, and the influence of the refreezing process of meltwater of the glaciers on the Yangtze River flow is examined with the proposed accumulated temperature deficit (ATD) index. It is found that annual runoff at the Batang station is not stable during the period 1960–2007. From 1960 to 1980, there was a rather strong decrease of 14.4 m3 s−1 year−1 on average in spite of the statistically significant increase in air temperature and rather stable precipitation. It is argued that the annual rate of glacier runoff generation is possibly controlled by the ATD rather than by the direct air temperature. Seasonal analysis indicates that ATD might be of greater influence in autumn and winter in affecting runoff than in spring and summer. The research in this paper may be helpful in understanding how the hydro-climatic conditions affect runoff generation in the cold regions.

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