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Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

Speleology in Kazakhstan

Shakalov on 11 Jul, 2012
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

Did you know?

That regolith is a general term for the layer of fragmental and unconsolidated rock material that nearly everywhere forms the surface of the land and overlies or covers the bedrock [6].?

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Your search for time series analysis (Keyword) returned 15 results for the whole karstbase:
Showing 1 to 15 of 15
THE DISCHARGE VARIABILITY OF SOME KARST SPRINGS IN BULGARIA STUDIED BY TIME-SERIES ANALYSIS, 1995, Pulidobosch A. , Padilla A. , Dimitrov D. , Machkova M. ,
The discharge variability of some karst springs in Bulgaria has been investigated in detail within a region situated in the semiarid zone where most of the principal processes controlling spring outflow (evapotranspiration, snow accumulation, karstic functioning) are significant. While the karstification was notable in the Kotel and Bistretz springs with a predominance of quickflow, in the Beden system the baseflow was higher and had a behaviour similar to a porous aquifer. Univariate and bivariate spectral analyses were applied as a suitable tool in preparation for a further application of precipitation-discharge relationship models

Contribution of correlation and spectral analyses to the regional study of a large karst aquifer (Charente, France), 1998, Larocque M. , Mangin A. , Razack M. , Banton O. ,
The purpose of the study is to demonstrate that correlation and spectral analyses can contribute to the regional study of a large karst aquifer. An example is presented for the La Rochefoucauld karst aquifer (Charente, France). Different types of spatially distributed time series provide valuable spatio-temporal information for the karat aquifer. The available time series consist of the spring flow rates, the flow rates at different locations in sinking streams, the piezometric levels, the electrical conductivity and temperature of the water, the atmospheric pressure and the precipitation The analysis of the flow rates at the springs shows that the aquifer empties very slowly and has a large storage capacity. Hydrodynamic links were established between three of the four rivers flowing on the aquifer and the springs. The results also demonstrate the important spatial heterogeneity of the aquifer and indicate that the most rapid flow occurs in the northern part of the aquifer. Hourly piezometric and electrical conductivity time series indicate that the transmissivity of the aquifer varies when some conductive channels become desaturated during the low water period. The delays between the distributed recharge and the piezometric level, between the localized river input and the how rates at the springs and between the electrical conductivities in rivers and the main spring provide information on the travel times in the aquifer, The observation of earth tides and barometric effects indicate that this apparently unconfined aquifer has a confined behaviour. (C) 1998 Elsevier Science B.V. All rights reserved

Fluorescence wavelength and intensity variations of cave waters, 1999, Baker A, Genty D,
The fluorescence properties of groundwaters percolating into four cave systems have been monitored over the period 1997-1998. Fluorescence was excited between 220 and 400 nm and the emission measured from 300 to 500 nm using a fluorescence spectrophotometer. Three fluorescence centres were observed; one at the excitation-emission pair of 290-340:395-430 nm, (humic-like, probably fulvic acid), one at 265-280:300-370 nm (protein like) and a less defined region of high fluorescence at 230-280:310-420 nm (humic and/or protein like). The most consistent fluorescence intensity was observed in the excitation-emission pair of 290-340:395-430 nm, attributed to a fulvic acid source. Subtle differences (5%) in the fluorescence excitation and emission wavelength of this fluorescence peak in the groundwater were observed between the four sites, and the fluorescence intensity varied considerably ( x 60) between the four sites. Both the wavelength and the intensity variations in fluorescence are caused by the differences in the vegetation cover, soil type and humification. Data from the most intensely monitored site (Brown’s Folly Mine, England; 9 sample stations, 10-20 days frequency sampling) revealed no spatial variability in the 290-340:395-430 nm (fulvic acid) fluorescence; in contrast time-series analysis suggests that the seasonal variations do occur, with a decrease in the emission wavelength correlating with the first (autumn) peak in fluorescence intensity, and a decrease in the excitation wavelength correlating with a second (winter) fluorescence intensity peak. Results demonstrate the potential of utilising fluorescence wavelength variations in sourcing karst groundwaters, and as a possible palaeoenvironmental proxy of the overlying soil conditions if trapped within the cave speleothems

Linear systems analysis in a karst aquifer, 1999, Long A. J. , Derickson R. G. ,
A linear systems analysis applied to ground-water flow is presented as an alternative modeling technique to traditional discretized ground-water models (i.e. finite-difference and finite-element), which require elaborate parameters and boundary conditions. Linear systems analysis has been used extensively for surface-water modeling and to 3 lesser extent for groundwater applications. We present a method for the analysis of an aquifer's response in hydraulic head to recharge that comprises two major components. The first component is to predict the drop in hydraulic head over time if recharge is eliminated. By fitting logarithmic curves to selected short-term hydraulic head recession periods, a long-term recession or 'base head' can be established. The estimation of base head is necessary for the second component of the method, which is the derivation of an impulse response function or transfer function. The transfer function H-as derived by deconvolution of two time series data sets - estimated recharge and the measured response in hydraulic head. An aquifer's response to recharge can be characterized and modeled by using the transfer function. which also establishes the time to peak response. the response time distribution, and the total memory length of the system. The method requires fitting smooth curves to the oscillatory transfer function derived by deconvolution in the Fourier transform domain. The smooth curve is considered to be the physically valid transfer function. In this analysis, curve fitting was more effective than other smoothing techniques commonly used. We applied the method to the karstic Madison aquifer and found that thr time to peak response is less than one month, the system's total memory is about six years, and a logarithmic curve best fits the system response. This method has potential to be useful as 3 predictive tool in aquifer management. (C) 1999 Elsevier Science B.V. All rights reserved

Rainfall-runoff relations for karstic springs. Part I: convolution and spectral analyses, 2000, Labat D. , Ababou R. , Mangin A. ,
Karstic basins contain large reserves of subsurface water. In this paper, three karstic systems located in the Pyrenees Mountains (Ariege, France) are studied. Long records of rainfall and discharge rates for these karstic springs are available, sampled at different rates: daily, hourly and half-hourly. This study aims at illustrating and assessing the capabilities and limitations of linear black-box methods for analysing rainfall-runoff type relationships and reconstructing runoffs from rainfall rate data using such systems. In this study, precipitation and discharge rates are considered as two autocorrelated and cross-correlated stochastic processes. A Linear and stationary rainfall-runoff model is adopted, which is used for identification and simulation purposes. Different versions are analysed, including a model based on a convolution integral between the precipitation rate P(tau) and a transfer function h(t - tau) which can be thought of as the unit impulse response of the system. It is shown that this linear stochastic model (i.e. the statistical version), although accurate in some respects, does not represent the hydraulic behaviour of the system very well during low flow episodes and floods. It is also shown that the use of Fourier analysis, alone, does not lead to a satisfactory reconstitution of observed runoff sequences. For these reasons, the use of non-linear random process input-output models based on Volterra integral series is proposed and discussed. (C) 2000 Elsevier Science B.V. All rights reserved

Rainfall-runoff relations for karstic springs: multifractal analyses, 2002, Labat D. , Mangin A. , Ababou R. ,
Karstic watersheds appear as highly as non-linear and non-stationary systems. The behaviour of karstic springs has been previously studied using non-linear simulation methods (Volterra expansion) and non-stationary analyses methods based on wavelet transforms. The main issue of karstic spring behaviour consists of the presence and the identification of characteristic time-scales. In order to highlight more precisely the scale-properties of the rainfall-runoff relations for karstic springs, the multifractal analysis is introduced. These methods are applied daily and half-hourly rainfall rates and runoffs measured on a three French karstic springs located in the Pyrenees Mountains (Ariege, France): Aliou, Baget and Fontestorbes. They are characterised by a variable development of the drainage systems. We have at our disposal long and uninterrupted series of data over period of several years, which constitute a high quality bank data. Multifractal analyses of both daily and half-hourly rainfall rates and runoffs give evident a scale-dependant behaviour. Effectively, it highlights the presence of different multifractal processes at each sampling rate. Using a universal class of multifractal models based on cascade multiplicative processes, the identified multifractal sub-processes are characterised by the classical parameters alpha and C-1. All these results should lead to several improvements in karstic springflow simulation models. (C) 2002 Elsevier Science B.V. All rights reserved

A frequency domain approach to groundwater recharge estimation in karst, 2004, Jukic D. , Icjukic V. ,
This paper presents an alternative method for determining the values of parameters of a groundwater recharge model. The phreatic zone of a karst aquifer is considered as the linear and time-invariant filter that transforms the input signal of groundwater recharge rates into the output signal of spring discharges. Similarities between transfer functions of total rainfall rates and transfer functions of groundwater recharge rates are the basis for developing the parametric periodogram depending on parameters of a groundwater recharge model. The values of parameters are estimated by minimizing the differences between the parametric periodogram and a periodogram of spring discharges. The approximate Whittle log likelihood function is the criterion for determining the optimal values of the parameters. By using this frequency domain approach, groundwater-balance calculations are avoided so the method can be applied on unexplored karst aquifers when groundwater-balance cannot be achieved without extensive geologic and hydrogeologic investigations. The results of the applications on two springs located in the Dinaric karst area in Croatia are discussed. (C) 2003 Elsevier B.V. All rights reserved

Water quality modelling of Jadro spring, 2004, Margeta J. , Fistanic I. ,
Management of water quality in karst is a specific problem. Water generally moves very fast by infiltration processes but far more by concentrated flows through fissures and openings in karst. This enables the entire surface pollution to be transferred fast and without filtration into groundwater springs. A typical example is the Jadro spring. Changes in water quality at the spring are sudden, but short. Turbidity as a major water quality problem for the karst springs regularly exceeds allowable standards. Former practice in problem solving has been reduced to intensive water disinfection in periods of great turbidity without analyses of disinfection by-products risks for water users. The main prerequisite for water quality control and an optimization of water disinfection is the knowledge of raw water quality and nature of occurrence. The analysis of monitoring data and their functional relationship with hydrological parameters enables establishment of a stochastic model that will help obtain better information on turbidity in different periods of the year. Using the model a great number of average monthly and extreme daily values are generated. By statistical analyses of these data possibility of occurrence of high turbidity in certain months is obtained. This information can be used for designing expert system for water quality management of karst springs. Thus, the time series model becomes a valuable tool in management of drinking water quality of the Jadro spring

Influence of hydrological and climatic parameters on spatial-temporal variability of fluorescence intensity and DOC of karst percolation waters in the Santana Cave System, Southeastern Brazil, 2005, Cruz J, Karmann I, Magdaleno Gb, Coichev N, Viana J,
Fluorescence intensity (FI) and organic carbon concentration of groundwater percolating through soil and rock into the Santana Cave were monitored at eight different cave sites between 2000 and 2002 to investigate their relationships to climatic parameters, stalactite discharge and thickness of rock overlying the cave. FI values, compared among sampling sites, are inversely proportional to depth and directly proportional to discharge; in contrast, dissolved organic matter (DOC) shows no significant spatial variability. Time-series analysis demonstrated similarities in DOC trends of different waters, but no correlation was observed with FI trends. Combined evaluation of DOC of infiltration waters, rainfall data and chemical parameters of Fe, O2, pH, Eh in soil solution indicate that peaks in DOC content coincide with more reduced conditions in the soil and have a lag time of 2-3 months after heavy showers. Variation of FI throughout the year occurs at all sampling sites but only higher drip discharge and rimstone pool waters were correlatable to rainfall events. FI of lower discharge sampling sites shows similar trends, but no relationship between drip discharge and rainfall variation was observed. Ranges and means of FI for all drip waters were significantly higher in the 2001-2002 period than in the preceding 2000-2001 period, which correlates with a 5.5 [deg]C increase in mean austral winter temperatures in 2001. Hence, FI variations of karst waters that form carbonate speleothems under a humid subtropical climate may provide a useful proxy in paleoenvironmental reconstruction

Modification and preservation of environmental signals in speleothems, 2006, Fairchild Ij, Smith Cl, Baker A, Fuller L, Spotl C, Mattey D, Mcdermott F, Eimp,
Speleothems are primarily studied in order to generate archives of climatic change and results have led to significant advances in identifying and dating major shifts in the climate system. However, the climatological meaning of many speleothem records cannot be interpreted unequivocally, this is particularly so for more subtle shifts and shorter time periods, but the use of multiple proxies and improving understanding of formation mechanisms offers a clear way forward. An explicit description of speleothem records as time series draws attention to the nature and importance of the signal filtering processes by which the weather, the seasons, and longer-term climatic and other environmental fluctuations become encoded in speleothems. We distinguish five sources of variation that influence speleothem geochemistry, i.e. atmospheric, vegetation/soil, karstic aquifer, primary speleothem crystal growth and secondary alteration, and give specific examples of their influence. The direct role of climate diminishes progressively through these five factors. We identify and review a number of processes identified in recent and current work that bear significantly on the conventional interpretation of speleothem records, for example: (1) speleothem geochemistry can vary seasonally and hence a research need is to establish the proportion of growth attributable to different seasons and whether this varies over time; (2) whereas there has traditionally been a focus on monthly mean delta O-18 data of atmospheric moisture, current work emphasizes the importance of understanding the synoptic processes that lead to characteristic isotope signals, since changing relative abundance of different weather types might control their variation on the longer-term; (3) the ecosystem and soil zone overlying the cave fundamentally imprint the carbon and trace element signals and can show characteristic variations with time; (4) new modelling on aquifer plumbing allows quantification of the effects of aquifer mixing; (5) recent work has emphasized the importance and seasonal variability Of CO2-degassing leading to calcite precipitation upflow of a depositional site on carbon isotope and trace element composition of speleothems; (6) although much is known about the chemical partitioning between water and stalagmites, variability in relation to crystal growth mechanisms and kinetics is a research frontier; (7) aragonite is susceptible to conversion to calcite with major loss of chemical information, but the controls on the rate of this process are obscure. Analytical factors are critical in generating high-resolution speleothem records. A variety of methods of trace element analysis is available, but standardization is a common problem with the most rapid methods. New stable isotope data on Irish stalagmite CC3 compares rapid laser-ablation techniques with the conventional analysis of micromilled powders and ion microprobe methods. A high degree of comparability between techniques for delta O-18 is found on the millimeter to centimeter scale, but a previously described high-amplitude oxygen isotope excursion around 8.3 ka is identified as an analytical artefact related to fractionation of the laser-analysis associated with sample cracking. High-frequency variability of not less than 0.5 parts per thousand may be an inherent feature of speleothem delta O-18 records. (c) 2005 Elsevier B.V. All rights reserved

Interactions hydrodynamiques surface/souterrain en milieu karstique [Surface water/Groundwater hydrodynamic interactions in karst watersheds], PhD Thesis, 2008, Baillycomte, Vincent

Ce travail de these s’inscrit dans la problematique generale de la caracterisation de l’alea inondation. Plus precisement, cette etude cherche a caracteriser l’influence des eaux souterraines sur la genese et la propagation des crues en surface dans les cas d’un bassin versant a forte composante karstique. Le site experimental du bassin versant du Coulazou, riviere temporaire qui traverse le massif karstique du Causse d’Aumelas a l’Ouest de Montpellier a ete retenu pour etudier de maniere approfondie les interactions entre les ecoulements de surface et les ecoulements souterrains en situation de crue.

L’etude hydrodynamique de ce systeme karst/riviere s’appuie sur un dispositif experimental adapte a l’observation des phenomenes hydrologiques (pluie, ruissellement) et hydrogeologiques (piezometrie en forage et dans les drains karstiques, suivi hydrodynamique des exutoires du systeme) tres rapides et tres intenses. La dynamique de ces ecoulements est liee au contexte climatique Mediterraneen mais aussi aux structures de drainage en surface et en souterrain qui permettent un transfert et un transit tres rapide des eaux au sein du systeme karst/riviere.

Une description hydrodynamique classique est completee par une approche fonctionnelle des echanges karst/riviere dans le but de mieux comprendre le fonctionnement hydrodynamique d’un tel systeme et de mettre en avant des indicateurs utilisables dans une demarche de modelisation des echanges surface/souterrain. Un premier modele est presente dans la derniere partie de ce document.

**********

This work aims at assessing the flooding hazard. More precisely, the study focuses on the influence of groundwater on the genesis and propagation of surface flows in the case of a highly karstified watershed. The experimental site of the Coulazou River, a temporary River which crosses the karstified formation of the Causse d’Aumelas (western Montpellier) has been selected to study hydrodynamic interactions between surface flows and groundwater flows during flood.

The hydrodynamic study of this karst/River system is based on a suitable experimental monitoring of both fast and intense hydrological (rain, runoff) and hydrogeological (water level in wells and karst drains, discharge measurements at the main outlets of the system) phenomenon. The specific hydrological response of this watershed is due to the Mediterranean climate but also to surface and underground drainage structures which allow very fast water flows within the karst/river system.

A common hydrodynamic description is followed by a functional approach of karst/river exchanges in order (i) to better understand the hydrodynamic behaviour of such a system and (ii) to highlight some indicators that can be used in a modelling approach. A first conceptual model of surface water/groundwater exchanges in karst terranes is presented in the latter part of the manuscript.
 


HYDROLOGIC CONNECTIONS AND DYNAMICS OF WATER MOVEMENT IN THE CLASSICAL KARST (KRAS) AQUIFER: EVIDENCE FROM FREQUENT CHEMICAL AND STABLE ISOTOPE SAMPLING, 2008, Doctor, D. H.

A review of past research on the hydrogeology of the Classical Karst (Kras) region and new information obtained from a two- year study using environmental tracers are presented in this paper. The main problems addressed are 1) the sources of water to the Kras aquifer resurgence zone—including the famous Timavo springs—under changing flow regimes; 2) a quantification of the storage volumes of the karst massif corresponding to flow regimes defined by hydrograph recessions of the Timavo springs; and 3) changing dynamics between deep phreatic conduit flow and shallow phreatic and epiphreatic storage within the aquifer resurgence zone as determined through changes in chemical and isotopic composition at springs and wells. Particular focus was placed on addressing the long-standing question of the influence of the Soča River on the ground waters of the aquifer resurgence zone. The results indicate that the alluvial aquifer supplied by the sinking of the Soča River on the northwestern edge of the massif contributes approximately 75% of the mean annual outflow to the smaller springs of the aquifer resurgence zone, and as much as 53% to the mean annual outflow of the Timavo springs. As a whole, the Soča River is estimated to contribute 56% of the average outflow of the Kras aquifer resurgence. The proportions of Soča River water increase under drier conditions, and decrease under wetter conditions. Time series analysis of oxygen stable isotope records indicate that the transit time of Soča River water to the Timavo springs, Sardos spring, and well B-4 is on the order of 1-2 months, depending on hydrological conditions. The total baseflow storage of the Timavo springs is estimated to be 518 million m3, and represents 88.5% of the storage capacity estimated for all flow regimes of the springs. The ratio of baseflow storage volume to the average annual volume discharged at the Timavo springs is 0.54. The Reka River sinking in Slovenia supplies substantial allogenic recharge to the aquifer; however, its influence on the northwest resurgence zone is limited to the Timavo springs, and is only a significant component of the spring discharge under flood conditions for relatively brief periods (several days to weeks). Sustainability of the trans-boundary aquifer of the Kras will benefit from maintaining high water quality in the Soča River, as well as focused water tracing experiments within the epiphreatic zone of the aquifer to better delineate the recharge zone and to identify sources of potential contamination to the Brestovica water supply well.


TIME SERIES ANALYSIS, MODELLING AND ASSESSMENT OF OPTIMAL EXPLOITATION OF THE NEMANJA KARST SPRINGS, SERBIA, 2010, Jemcov I. , Petri? M.
The time series analysis was applied in the case-study of a karst aquifer in Serbia in order to study its functioning, hydrodynamic behavior and hydraulic properties. Focusing on the definition of groundwater budget, due to very complex functioning of karst systems the correlation and spectral analyses were used to emphasize the importance of transforming the input data precipitation to effective infiltration. Thee characterization of karst aquifer was further improved by separating the output component discharge to base flow and flatfoot components. Additionally, the importance of these transformations was proved in application of the regression model for the simulation of discharges based on the effective infiltration functions. A recharge-discharge model was applied in accordance with the active groundwater management, defining optimal exploitable regimes, which included the analyses of storage changes in karst water reservoirs under natural conditions, and calculation of the potential exploitation conditions.

HYDROGEOLOGICAL STUDY OF THE MALEN?ICA KARST SPRING (SW SLOVENIA) BY MEANS OF A TIME SERIES ANALYSIS, 2010, Kova?i? G.
Time series analyses are often used for the investigation of karst aquifers, but are only rarely employed in a way of using a large number of spatially distributed time series. Furthermore, only a small number of applications employ other types of hydrological data apart from rainfall, water level and discharge. The presented study of the Malen?ica karst spring aquifer underlines the usefulness of the simultaneous auto and cross-correlation analysis of daily and hourly hydrological data sets, including discharge, water level, temperature, electrical conductivity and rainfall on a regional scale. The results of the autocorrelation analysis show that the storage capacity of the spring is moderate, but this does not indicate that the system, which is characterized by prevailing conduit porosity, is less intensively karstifed. This suggests that well karstied systems of a more complex structure can have higher memory effects than less complex systems. The results of the cross-correlation analysis show that karst springs and watercourses in the investigated area react instantly and simultaneously to rather homogeneous precipitation, yet with different intensity. In such cases a cross-correlation analysis between rainfall or ponors as inputs and springs as outputs does not provide sufficient information on the hydrogeological functioning of the system, whereas the results of a cross-correlation analysis of electrical conductivity data sets provide valuable information on its functioning and can be easily compared to those obtained by tracer tests. On the other hand, the applicability of a temperature time series in such complex karst systems is limited. A comparative analysis of the results of the time series analyses performed in successive hydrological years has proven that the selection of the hydrological year can have strong effects on the results of a time series analysis.

Temporal variability of karst aquifer response time established by the sliding-windows cross-correlation method, 2013, Delbarta Célestine, Valdesd Danièle, Barbecotg Florent, Tognellia Antoine, Richona Patrick, Couchouxh Laurent

We study the temporal variability of water transfer through the infiltration zone of a karst aquifer by estimating the impulse response of the system using cross-correlogram analyses between rainfall and piezometric level time series. We apply a sliding-window cross-correlation method, which calculates cross-correlograms on partially superposed short time series windows. We apply this method for rainfall and piezometric level time series at six boreholes in a fractured karstic aquifer located in Burgundy, France. Based on cross-correlogram functions, we obtain a time series of response time. At most of the boreholes, the cross-correlation functions change over time, and the response times vary seasonally, being shorter during the summer. This unusual structure can be partly explained by the seasonal variability in rainfall intensity, which is higher during the summer (May–September), inducing the seasonal behaviour of the epikarst. During the summer, when rainfall intensity is higher, the epikarst is more easily and quickly saturated. This induces an increase in lateral water transfer within the epikarst and an increase in concentrated fast flows. We also show that the response time seems to tend towards a limit which represents the maximum saturation of the epikarst.


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