Abstract. We propose new metrics to assist global sensitivity analysis, GSA, of hydrological and Earth systems. Our approach allows assessing the impact uncertain parameters on main features probability density function, pdf, a target model output, y. These include expected value y, spread around mean degree symmetry tailedness pdf Since reliable assessment higher-order statistical moments can be computationally demanding, we couple our GSA with surrogate model, approximating full response...

We perform a set of detailed numerical simulations single-phase, fully saturated flow in stochastically generated, three-dimensional pore structures with diverse porosities (\ensuremath{\phi}) and degrees connectivity, analyze the probability density functions (PDFs) sizes, $S$, vertical velocity components, $w$, which are aligned mean direction. Both PDFs markedly skewed pronounced positive tails. This feature PDF is dictated by structure determines shortest travel times, one key transport...

The properties of heterogeneous media vary spatially in a manner that can seldom be described with certainty. It may, however, possible to describe the spatial variability these terms geostatistical parameters such as mean, integral (spatial correlation) scale, and variance. Neuman et al. (2004) proposed graphical method estimate (natural) log transmissivity on basis quasi–steady state head data when randomly confined aquifer is pumped at constant rate from fully penetrating well. They...

The analysis of pumping tests has traditionally relied on analytical solutions groundwater flow equations in relatively simple domains, consisting one or at most a few units having uniform hydraulic properties. Recently, attention been shifting toward methods and that would allow to characterize subsurface heterogeneities greater detail. On hand, geostatistical inverse are being used assess the spatial variability parameters, such as permeability porosity, basis multiple cross‐hole pressure...

The subsurface consists of porous and fractured materials exhibiting a hierarchical geologic structure, which gives rise to systematic random spatial directional variations in hydraulic transport properties on multiplicity scales. Traditional geostatistical moment analysis allows one infer the covariance structure such hierarchical, multiscale basis numerous measurements given support scale across domain or “window” length scale. resultant sample variogram often appears fit stationary model...

Key Points Embedding stochastic moment equations of flow in ensemble Kalman filter Avoiding need for Monte Carlo simulations batch inversion Moment Equations

Abstract We propose a set of new indices to assist global sensitivity analysis in the presence data allowing for interpretations based on collection diverse models whose parameters could be affected by uncertainty. Our metrics enable us assess various features (as rendered through statistical moments) probability density function quantity interest with respect imperfect knowledge (i) interpretive model employed characterize system behavior and (ii) ensuing parameters. exemplify our...

We investigate the intricate patterns associated with space-time dynamics displayed by (i) surface topography (Z) and (ii) reaction rates (R) resulting from direct nano-scale imaging of calcite-water interfaces subject to dissolution. The analysis rests on a variogram modeling approach. latter has been suggested as promising in unveiling major exhibited hydrogeological quantities across large scale aquifer systems. Transferability theoretical operational framework interpret geochemical...

We focus on the assessment of spatiotemporal distributions precipitates in complex porous systems under a variety sources uncertainty. Our study specifically targets calcium carbonate (CaCO3) biomineralizing techniques, that are significant interest across wide range engineering applications. In this context, one can note favoring mineralization markedly alter pore space structure as well hydrodynamic parameters materials. Otherwise, uncertainties surrounding our ability to assess hydraulic...

Assessment of hydrogeological parameters such as aquifer permeability, thermal conductivity, and dispersion coefficients is critical for comprehensive groundwater resource assessment. In this context we provide experimental analyses slug tests performed upon considering a confined system where hydraulic, thermal, solute transport processes take place. Design execution experiments are supported by detailed numerical modeling analysis taking into account the intimately coupled nature these...

Our work targets mapping of pesticides application rates within the European Union at 250m spatial resolution. Source data include global estimates pesticide inputs, high resolution crop maps and usage reported by EUROSTAT official figures. The previously published in PEST-CHEMGRIDS are used as a first guess estimate. This is then corrected using calibration dataset gathered from use agriculture. estimation applied mass country type combined with maps. procedure explicitly accounts quality...

Abstract We provide a sound theoretical framework for the characterization of randomly heterogeneous spatial fields exhibiting multi‐modal, long‐tailed probability densities. Multi‐modal distributions are at core conceptual models employed to represent heterogeneity hydrogeological or geochemical systems across which one can otherwise distinguish diverse regions whose location is uncertain. Within each region, quantity interest shows distinct pattern that be described through generally...

We analyze theoretically the ability of model quality (sometimes termed information or discrimination) criteria such as negative log likelihood NLL , Bayesian BIC and KIC theoretic AIC, AICc HIC to estimate (1) parameter vector variogram hydraulic conductivity ( Y = ln K ), (2) statistical parameters proportional head measurement error variances, respectively, in context geostatistical groundwater flow inversion. Our analysis extends work Hernandez et al. (2003, 2006) Riva (2009), who...