Transit times—the link between hydrology and water quality at the catchment scale

Wiley Interdisciplinary Reviews Water, Journal Year: 2016, Volume and Issue: 3(5), P. 629 - 657

Published: May 16, 2016

In spite of trying to understand processes in the same spatial domain, catchment hydrology and water quality scientific communities are relatively disconnected so their respective models. This is emphasized by an inadequate representation transport processes, both catchment‐scale hydrological While many models at scale only account for pressure propagation not mass transfer, typically limited overly simplistic representations flow processes. With objective raising awareness this issue outlining potential ways forward we provide a nontechnical overview (1) importance hydrology‐controlled through systems as link between quality; (2) limitations current generation models; (3) concept transit times tools quantify transport; (4) benefits time based formulations solute There emerging evidence that explicit formulation on has improve understanding integrated system dynamics catchments stronger WIREs Water 2016, 3:629–657. doi: 10.1002/wat2.1155 article categorized under: Science > Hydrological Processes Quality

Language: Английский

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The Demographics of Water: A Review of Water Ages in the Critical Zone

Reviews of Geophysics, Journal Year: 2019, Volume and Issue: 57(3), P. 800 - 834

Published: May 20, 2019

Abstract The time that water takes to travel through the terrestrial hydrological cycle and critical zone is of great interest in Earth system sciences with broad implications for quality quantity. Most age studies date have focused on individual compartments (or subdisciplines) such as unsaturated or saturated zone, vegetation, atmosphere, rivers. However, recent shown processes at interfaces between (e.g., soil‐atmosphere soil‐groundwater) govern distribution fluxes these thus can greatly affect times. variation from complete nearly absent mixing affects ages compartments. This especially case highly heterogeneous top vegetation bottom groundwater storage. Here, we review a wide variety about provide (1) an overview new prospects challenges use tracers study ages, (2) discussion limiting assumptions linked our lack process understanding methodological transfer estimations disciplines compartments, (3) vision how improve future interdisciplinary efforts better understand feedbacks soil, groundwater, surface control zone.

Language: Английский

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Using SAS functions and high‐resolution isotope data to unravel travel time distributions in headwater catchments

Water Resources Research, Journal Year: 2017, Volume and Issue: 53(3), P. 1864 - 1878

Published: Feb. 11, 2017

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 normalized rank storage. computed appropriate solution master equation defining formally evolution travel times. By representing way which generates outflows composed different ages, main mechanism regulating composition runoff is clearly identified detailed comparison with empirical sets possible. Properly calibrated numerical tools provide simulations convincingly reproduce complex measured signals daily deuterium content stream waters during wet dry periods. Results for under consideration consistent other recent studies indicating tendency natural catchments preferentially release younger available water. The study shows law SAS prove powerful tool explain also has potential less intensively monitored sites.

Language: Английский

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Toward catchment hydro‐biogeochemical theories

Wiley Interdisciplinary Reviews Water, Journal Year: 2020, Volume and Issue: 8(1)

Published: Dec. 3, 2020

Abstract Headwater catchments are the fundamental units that connect land to ocean. Hydrological flow and biogeochemical processes intricately coupled, yet their respective sciences have progressed without much integration. Reaction kinetic theories prescribe rate dependence on environmental variables (e.g., temperature water content) advanced substantially, mostly in well‐mixed reactors, columns, warming experiments considering characteristics of hydrological at catchment scale. These shown significant divergence from observations natural systems. On other hand, theories, including transit time theory, substantially not been incorporated into understanding reactions Here we advocate for development integrated hydro‐biogeochemical across gradients climate, vegetation, geology conditions. The lack such presents barriers mechanisms forecasting future Critical Zone under human‐ climate‐induced perturbations. Although integration has started co‐located measurements well way, tremendous challenges remain. In particular, even this era “big data,” still limited by data will need (1) intensify beyond river channels characterize vertical connectivity broadly shallow deep subsurface; (2) expand older dating scales reflected stable isotopes; (3) combine use reactive solutes, nonreactive tracers, (4) augment environments undergoing rapid changes. To develop it is essential engage models all stages model‐informed collection strategies maximize usage; adopt a “simple but simplistic,” or fit‐for‐purpose approach include process‐based models; blend data‐driven framework “theory‐guided science.” Within hypothesis testing, model‐data fusion can advance mechanistically link catchments' internal structures external drivers functioning. It only field hydro‐biogeochemistry, also enable hind‐ fore‐casting serve society large. Broadly, education cultivate thinkers intersections traditional disciplines with hollistic approaches interacting complex earth This article categorized under: Engineering Water > Methods

Language: Английский

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Transit Time Estimation in Catchments: Recent Developments and Future Directions

Water Resources Research, Journal Year: 2022, Volume and Issue: 58(11)

Published: Nov. 1, 2022

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 distributed models, direct estimates from controlled experiments, young fractions, ensemble hydrograph separation. unify some heterogeneity literature that crept many approaches, an attempt to clarify key differences similarities among them. Finally, point open questions research, what still need theory, work, community practice.

Language: Английский

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Snowmelt controls on concentration‐discharge relationships and the balance of oxidative and acid‐base weathering fluxes in an alpine catchment, East River, Colorado

Water Resources Research, Journal Year: 2017, Volume and Issue: 53(3), P. 2507 - 2523

Published: March 1, 2017

Abstract Although important for riverine solute and nutrient fluxes, the connections between biogeochemical processes subsurface hydrology remain poorly characterized. We investigate these couplings in East River, CO, a high‐elevation shale‐dominated catchment Rocky Mountains, using concentration‐discharge (C‐Q) relationships major cations, anions, organic carbon. Dissolved carbon (DOC) displays positive C‐Q relationship with clockwise hysteresis, indicating mobilization depletion of DOC upper soil horizons emphasizing importance shallow flow paths during snowmelt. Cation anion concentrations demonstrate that carbonate weathering, which dominates is promoted by both sulfuric acid derived from pyrite oxidation shale bedrock carbonic respiration. Sulfuric weathering base conditions when waters infiltrate below inferred front, whereas plays dominant role snowmelt as result paths. Differential solutes suggest infiltrating approach calcite saturation before reaching after reduces alkalinity. This reduction alkalinity results CO 2 outgassing equilibrate to surface conditions, export roughly 33% annually. Future changes dynamics control balance may substantially alter cycling River. Ultimately, we differential can provide unique insights into complex operate at scales.

Language: Английский

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Spatial Patterns of Water Age: Using Young Water Fractions to Improve the Characterization of Transit Times in Contrasting Catchments

Water Resources Research, Journal Year: 2018, Volume and Issue: 54(7), P. 4767 - 4784

Published: June 26, 2018

Abstract Transit time distributions (TTDs) are crucial descriptors of flow and transport processes in catchments, which can be determined from stable water isotope data. Recently, the young fraction ( F yw ) has been introduced as an additional metric derivable seasonal cycles. In this study, we calculated TTDs using monthly data 24 contrasting subcatchments a mesoscale catchment (3,300 km 2 Germany. ranged 0.01 to 0.27 (mean = 0.11) was smallest mountainous catchments. Assuming gamma‐shaped TTDs, stationary with convolution integral method for each subcatchment. The first calibrated against only (i.e., traditional calibration) and, second, multiobjective calibration estimates constraint. This yielded largely differing TTD parameters even neighboring values below 0.1 generally involving delayed peak gamma‐distribution shape parameter > 1). While resulted large uncertainties parameters, these were reduced calibration, thereby improving assessment mean transit times (2 years on average, ranging between 9.6 months 5.6 years). highlights need uncertainty when simple models shows that might not yield optimum solution it may give nonconsistent . Given robustness estimates, should thus aim at accurately describing both measured order improve description

Language: Английский

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Headwater stream length dynamics across four physiographic provinces of theAppalachianHighlands

Hydrological Processes, Journal Year: 2017, Volume and Issue: 31(19), P. 3350 - 3363

Published: June 22, 2017

Abstract Understanding patterns of expansion, contraction, and disconnection headwater stream length in diverse settings is invaluable for the effective management water resources as well informing research hydrology, ecology, biogeochemistry temporary streams. More accurate mapping network quantitative measures flow duration vast regions facilitate implementation quality regulation other policies to protect waterways. We determined connectivity wet geomorphic channel 3 forested catchments (<75 ha) each 4 physiographic provinces Appalachian Highlands: New England, Plateau, Valley Ridge, Blue Ridge. mapped 7 times at catchment characterize conditions between exceedance probabilities <5% >90% mean daily discharge. Stream dynamics reflected geologic controls both regional local scales. Wet was most variable two Ridge on a shale scarp slope changed least The density source area origins differed crystalline sedimentary provinces, Plateau had fewer with much larger contributing areas than England However, surface depended lithology, structure, distribution surficial deposits such boulders, glacially derived material, colluival debris or sediment valley fills. Several proxies indicate magnitude dynamics, including bankfull width, connectivity, base index, ratio length. Consideration characteristics multiple spatial scales imperative future investigations intermittency headwaters.

Language: Английский

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Linking high‐frequency DOC dynamics to the age of connected water sources

Water Resources Research, Journal Year: 2016, Volume and Issue: 52(7), P. 5232 - 5247

Published: June 15, 2016

Abstract We combined high‐frequency dissolved organic matter fluorescence (FDOM) data with stable isotope observations to identify the sources and ages of runoff that cause temporal variability in carbon (DOC) within a peat‐dominated Scottish catchment. FDOM was strongly correlated (r 2 ∼ 0.8) DOC, allowing inference 15 min time series. captured 34 events over range hydrological conditions. Along marked seasonality, different event responses were observed during summer depending on dry or wet antecedent The majority exhibited anticlockwise hysteresis as result expansion riparian saturation zone, mobilizing previously unconnected DOC sources. Water from main extracted tracer‐aided model. Particularly useful overland flow, which negatively concentration. Overland flow age, ranged between 0.2 360 days, reflected conditions, younger water generally highest concentrations events. During small response proportionally higher due displacement mixing volumes highly concentrated soil waters by new precipitation. large zone expands layers hillslopes causing peaks DOC. However, these limited dilution supply. This study highlights utility linking measurements other tracers, effects hydrologic connectivity conditions delivery streams be assessed.

Language: Английский

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Signature‐Domain Calibration of Hydrological Models Using Approximate Bayesian Computation: Empirical Analysis of Fundamental Properties

Water Resources Research, Journal Year: 2018, Volume and Issue: 54(6), P. 3958 - 3987

Published: April 9, 2018

Abstract This study investigates Bayesian signature‐domain inference of hydrological models using Approximate Computation (ABC) algorithms, and compares it to “traditional” time‐domain inference. Our focus is on the quantification predictive uncertainty in streamflow time series understanding information content particular combinations signatures. A combination synthetic real data experiments conceptual rainfall‐runoff employed. Synthetic demonstrate: (i) general consistency signature inferences, (ii) ability estimate error model parameters (reliably quantify uncertainty) even when calibrating domain, (iii) potential robustness (probabilistic) misspecified (e.g., by unaccounted timing errors). The also suggest limitations approach terms loss (nonsufficient) statistics are used, increased computational costs incurred ABC implementation. Real confirm viability its with quantification. In addition, we demonstrate utility flashiness index for estimation parameters, show that signatures based Flow Duration Curve alone insufficient calibrate controlling dynamics. Overall, further establishes (implemented ABC) as a promising method comparing signatures, prediction under data‐scarce conditions, and, certain circumstances, mitigating impact deficiencies formulation model.

Language: Английский

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