Application of time-series analyses to the hydrological functioning of an Alpine karstic system: the case of Bange-L’Eau-Morte

Abstract. This paper analyses the hydrological functioning of the Bange-L’Eau-Morte karstic system using classical and original techniques, recession curves, correlation and spectral analyses, noise analysis and wavelet analyses. The main characteristics that can be deduced are the recession coefficients, the dynamic volume of storage, the response time of the system, the quickflow and baseflow components and the snowmelt characteristics. The non-stationary and timescale-dependent behaviour of the system is studied and particular features of the runoff are shown. The step-by-step use of these different techniques provides a general methodology applicable to different karstic systems to provide quantifiable and objective criteria for differentiation and comparison of karstic systems. Keywords: karstic hydrology, Bauges mountains, recession curves, correlation and spectral analysis, wavelet analysis, snowmelt

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An Application of Correlation and Spectral Analysis in Hydrological Study of Neighboring Karst Springs

Water ◽

10.3390/w12123570 ◽

2020 ◽

Vol 12 (12) ◽

pp. 3570

Author(s):

Vesna Denić-Jukić ◽

Ana Lozić ◽

Damir Jukić

Keyword(s):

Time Series ◽

Spectral Analysis ◽

Correlation Analysis ◽

Time Series Analysis ◽

Correlation Functions ◽

Karst Area ◽

Mathematical Tool ◽

Karst Springs ◽

Series Analysis ◽

Correlation And Spectral Analysis

Various methods of time series analysis have been used in studies of karst hydrological systems. Among these methods, correlation and spectral analysis have had an important role. The correlation analysis most often has been based on determination of correlation coefficients and correlation functions. Partial correlation functions (PCF) are a mathematical tool of the correlation analysis which practical applicability in karst hydrology is insufficiently explored. In this study, the correlation and spectral analysis are applied on the catchment of Rumin Springs located in the Dinaric karst area between Croatia and Bosnia and Herzegovina. The available daily data are the rainfall, air temperature and relative humidity from three locations, as well as the discharge from two springs. The periods before and after the construction of HPP Orlovac in 1973 are analyzed. The basic hypothesis is that a difference between PCF obtained for two neighboring karst springs describe a difference in their functioning. The results of application show that PCF can resolve some ambiguities concerning the effects included in correlation functions and can provide the additional information that cannot be obtained by other methods of time series analysis. The obtained results are mostly in accordance with the present knowledge, and they support the existing hypotheses about the functioning of Rumin Springs.

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Correlating the non-linear time series and spectral properties of IGR J17091–3624: is it similar to GRS 1915+105?

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa071 ◽

2020 ◽

Vol 492 (3) ◽

pp. 4033-4042

Author(s):

Oluwashina Adegoke ◽

Banibrata Mukhopadhyay ◽

Ranjeev Misra

Keyword(s):

Time Series ◽

Spectral Analysis ◽

Integral Method ◽

Spectral Properties ◽

Linear Time ◽

Poisson Noise ◽

Accretion Discs ◽

Correlation Integral ◽

Non Linear ◽

Time Series Analyses

ABSTRACT Using the correlation integral method, we explore the non-linear properties of IGR J17091–3624 by comparing the underlying behaviour to GRS 1915+105. We find that while GRS 1915+105 is known to reveal a combination of fractal (or even chaotic) and stochastic behaviours depending on its temporal class, IGR J17091–3624 mostly shows stochastic behaviour. Therefore, although several observations find that IGR J17091–3624 is similar to GRS 1915+105, and that they have temporal classes in common, the underlying non-linear time series analyses offer a different view. Nevertheless, the ratio of the Poisson noise to rms variation for IGR J17091–3624 turns out to be high, suggesting that it is dominated by Poisson noise. Hence it might plausibly lead to the suppression of its non-linear properties, if there is any. Indeed, IGR J17091–3624 is a very faint source compared with GRS 1915+105. However, by increasing the time bin, some of the temporal classes of IGR J17091–3624 show deviation from stochasticity, indicating the plausibility of a higher fractal dimension. Along with spectral analysis, overall IGR J17091–3624 seems to reveal three different accretion classes: slim, Keplerian and advective accretion discs.

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