The probability density functions (pdf's) of travel and residence times are key descriptors the mechanisms through which catchments retain release old event water, transporting solutes to receiving water bodies. In this paper we analyze theoretically such pdf's, whose proper characterization reveals important conceptual practical differences. A general stochastic framework applicable arbitrary catchment control volumes is adopted, where time-variable precipitation, evapotranspiration...

We propose a mathematical framework for the general definition and computation of travel time distributions defined by closure catchment control volume, where input flux is an arbitrary rainfall pattern output fluxes are green blue water flows (namely, evapotranspiration hydrologic response embedding runoff production through soil dynamics). The relevance problem both practical, owing to implications in watershed modeling, conceptual linkages explanations theory provides, chiefly concerning...

Landscape and climate alterations foreshadow global-scale shifts of river flow regimes. However, a theory that identifies the range foreseen impacts on streamflows resulting from inhomogeneous forcings sensitivity gradients across diverse regimes is lacking. Here, we derive measurable index embedding landscape attributes (the ratio mean interarrival streamflow-producing rainfall events catchment response time) discriminates erratic with enhanced intraseasonal streamflow variability...

Abstract We discuss a recent theoretical approach combining catchment‐scale flow and transport processes into unified framework. The is designed to characterize the hydrochemistry of hydrologic systems meet challenges posed by empirical evidence. StorAge Selection functions (SAS) are defined represent way catchment storage supplies outflows with water different ages, thus regulating chemical composition out‐fluxes. Biogeochemical also reflected in evolving residence time distribution...

Abstract We use high‐resolution tracer data from an experimental site to test theoretical approaches that integrate catchment‐scale flow and transport processes in a unified framework centered on selective age sampling by streamflow evapotranspiration fluxes. Transport operating at the catchment scale are reflected evolving residence time distribution of water storage selection operated out‐fluxes. Such described here through StorAge Selection (SAS) functions parameterized as power laws...

Abstract Water transit time is now a standard measure in catchment hydrological and ecohydrological research. The last comprehensive review of modeling approaches was published 15+ years ago. But since then the field has largely expanded with new data, theory applications. Here, we these developments focus on water‐age‐balance data‐based approaches. We discuss compare methods including StorAge‐Selection functions, well/partially mixed compartments, water age tracking through spatially...

Many details about the flow of water in soils a hillslope are unknowable given current technologies. One way learning bulk effects velocity distributions on hillslopes is through use tracers. However, this paper will demonstrate that interpretation tracer information needs to become more sophisticated. The reviews, and complements with mathematical arguments specific examples, theory practice distribution(s) times particles injected rainfall spend traveling catchment up control section...

This paper aims at a first theoretical step toward the probabilistic modeling of nutrient contents in catchment‐scale soil states. To this end, we wish to characterize probabilistically slow, leaching‐prone component hydrologic response, which chiefly determines export dissolved nutrients from soil, as result interactions between mobile/immobile phases along pathways runoff formation. The influence temporal fluctuations moisture on slow components is thus investigated by means stochastic...

Abstract Here we present a theoretical interpretation of high‐frequency, high‐quality tracer time series from the Hafren catchment at Plynlimon in mid‐Wales. We make use formulation transport by travel distributions to model chloride originating atmospheric deposition and compute catchment‐scale distributions. The relevance approach lies explanatory power chosen tools, particularly highlight hydrologic processes otherwise clouded integrated nature measured outflux signal. analysis reveals...

Nonlinear storage‐discharge relations may explain important hydrologic features frequently observed under a variety of environmental conditions. In this paper the catchment dynamic storage problem is addressed by incorporating nonlinear in stochastic framework to derive statistical distribution and duration curve streamflows river basins. Such goal achieved extending recent analytical solutions for seasonal probability discharges derived from description soil moisture dynamics at basin...

Abstract The analysis and estimation of extreme event occurrences is a central problem in many fields geoscience. Advancements the study events have recently been limited, arguably connection with asymptotic assumptions traditional value theory (EVT) its focusing on small fraction available observations representing tail properties underlying generation process. Here we develop Metastatistical Extreme Value framework (MEV) which relaxes limiting at basis EVT accounts for full distribution...

Abstract We combine experimental and modeling results from a headwater catchment at the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA, to explore link between stream solute dynamics water age. A theoretical framework based on age dynamics, which represents general basis for characterizing transport scale, is here applied conservative weathering‐derived solutes. Based available information about hydrology of site, an integrated model was developed used compute hydrochemical...

Due to the challenges in upscaling daily climatic forcing geological time, physically realistic models describing how rainfall drives fluvial erosion are lacking. To bridge this gap between short‐term hydrology and long‐term geomorphology, we derive a theoretical framework for rates driven by climate integrating an established stochastic‐mechanistic model of into threshold‐stochastic formulation stream power. The hydrological theory provides equations streamflow probability distribution as...

Abstract In the majority of existing studies, streams are conceived as static objects that occupy predefined regions landscape. However, empirical observations suggest stream networks systematically and ubiquitously featured by significant expansion/retraction dynamics produced hydrologic climatic variability. This contribution presents novel data about active drainage network a 5 km 2 headwater catchment in Italian Alps. The has been extensively monitored with biweekly temporal resolution...

Monitoring ephemeral and intermittent streams is a major challenge in hydrology. On-site inspections may be impractical difficult-to-access environments. Motivated by the latest advancements digital cameras computer vision techniques, this work, we describe development application of stage-camera system to monitor water level ungauged headwater streams. The encompasses consumer-grade wildlife camera with near-infrared (NIR) night capabilities white pole that serves as reference object...

Abstract Understanding the spatio‐temporal dynamics of runoff generation in headwater catchments is challenging, due to intermittent and fragmented nature surface flows. The active stream network non‐perennial rivers contracts expands, with a dynamic behavior that depends on complex interplay among climate, topography, geology. In this work, CATchment HYdrology, an integrated surface–subsurface hydrological model (ISSHM), used simulate two virtual same, spatially homogeneous, subsurface...

This paper deals with hydrologic studies relevant to the works engineered for protection of city Venice (Italy) from major flooding under significant climate change scenarios. Such foresee temporary closure lagoon surrounding tidal exchanges Adriatic Sea in times sea storm surges via operation a set mobile gates. A general model ∼2000 km 2 mainland contributing runoff is coupled time and space 2‐D finite element hydrodynamics forecast maximum lagoonal closure. We also study impacts...

In this paper we extend previous mathematical results on the probabilistic modeling of base flows driven by spatial and temporal fluctuations soil moisture affected intermittent rainfall forcings heterogeneous transport, soil, vegetation properties. Rainfall is modeled as a zero‐dimensional marked Poisson process with exponentially distributed intensity, various descriptors heterogeneity are used. The master equation for probability distribution (pdf) flow (here epitomized mean daily rate in...

A novel approach is proposed to estimate the natural streamflow regime of a river and assess extent alterations induced by dam operation related anthropogenic (e.g., agricultural, hydropower) water uses in engineered basins. The method consists comparison between seasonal probability density function (pdf) observed streamflows purportedly pdf obtained recently validated probabilistic model. model employs minimum landscape climate parameters unequivocally separates effects regulations from...

Travel times are fundamental catchment descriptors that blend key information about storage, geochemistry, flow pathways and sources of water into a coherent mathematical framework. Here we analyze travel time distributions (TTDs) (and related attributes) estimated on the basis extensive hydrochemical available for Hupsel Brook lowland in Netherlands. The relevance work is perceived to lie general importance characterizing nonstationary TTDs capture transport properties, here chloride flux...

This work focuses on the description and use of probability density functions (pdfs) travel, residence evapotranspiration times, which are comprehensive descriptors fate rainfall water particles traveling through catchments, provide key information hydrologic flowpaths, partitioning precipitation, circulation turnover pollutants. Exploiting some analytical solutions to transport problem derived by Botter et al. (2011), this paper analyzes features time pdfs resulting from different...

The identification of the capacity a run‐of‐river plant which allows for optimal utilization available water resources is challenging task, mainly because inherent temporal variability river flows. This paper proposes an analytical framework to describe energy production and economic profitability small power plants on basis underlying streamflow regime. We provide expressions maximize produced as function flow duration curve minimum environmental requirements downstream intake. Similar are...

Abstract A theoretical analysis of transport in a controlled hydrologic volume, inclusive two willow trees and forced by erratic water inputs, is carried out contrasting the experimental data described companion paper. The refer to large lysimeter different fluorobenzoic acids seen as tracers. Export solute modeled through recently developed framework which accounts for nonstationary travel time distributions where we parameterize how output fluxes (namely, discharge evapotranspiration)...