Causes, Responses, and Implications of Anthropogenic versus Natural Flow Intermittence in River Networks

BioScience, Journal Year: 2022, Volume and Issue: 73(1), P. 9 - 22

Published: Dec. 7, 2022

Abstract Rivers that do not flow year-round are the predominant type of running waters on Earth. Despite a burgeoning literature natural intermittence (NFI), knowledge about hydrological causes and ecological effects human-induced, anthropogenic (AFI) remains limited. NFI AFI could generate contrasting biological responses in rivers because distinct underlying drying evolutionary adaptations their biota. We first review show how different drivers alter timing, frequency duration drying, compared with NFI. Second, we evaluate possible differences biodiversity responses, functions, ecosystem services between AFI. Last, outline gaps management needs related to Because hydrologic characteristics impacts AFI, ignoring distinction undermine intermittent ephemeral streams exacerbate risks ecosystems societies downstream.

Language: Английский

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Evaporation enhancement drives the European water-budget deficit during multi-year droughts

Hydrology and earth system sciences, Journal Year: 2022, Volume and Issue: 26(6), P. 1527 - 1543

Published: March 22, 2022

Abstract. In a warming climate, periods with lower than average precipitation will increase in frequency and intensity. During such periods, known as meteorological droughts, the decline annual runoff may be proportionally larger corresponding precipitation. Reasons behind this exacerbation of deficit during dry remain largely unknown, challenges predictability when occur future how intense it be. work, we tested hypothesis that droughts is common feature across climates, driven by evaporation enhancement. We relied on multidecadal records streamflow for more 200 catchment areas various European which distinctively show emergence similar exacerbated identified previous studies, i.e. order −20 % to −40 less what expected from deficits. The magnitude two three times basins located regions wet regions, qualitatively correlated an +11 +33 over characterized energy-limited water-limited regimes, respectively. Thus, enhanced atmospheric vegetation demand moisture induces nonlinear precipitation-runoff relationship low-flow results unexpectedly large decrease already low water availability. Forecasting onset, magnitude, duration these drops have paramount societal ecological implications, especially given their supporting role safeguarding water, food, energy. outcome are prone climates regimes makes further understanding its patterns urgent priority water-resource planning management drier climate.

Language: Английский

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Flow intermittence prediction using a hybrid hydrological modelling approach: influence of observed intermittence data on the training of a random forest model

Hydrology and earth system sciences, Journal Year: 2024, Volume and Issue: 28(4), P. 851 - 871

Published: Feb. 23, 2024

Abstract. Rivers are rich in biodiversity and act as ecological corridors for plant animal species. With climate change increasing anthropogenic water demand, more frequent prolonged periods of drying river systems expected, endangering ecosystems. However, understanding predicting the hydrological mechanisms that control periodic rewetting rivers is challenging due to a lack studies observations, particularly non-perennial rivers. Within framework Horizon 2020 DRYvER (Drying River Networks Climate Change) project, modelling study flow intermittence being carried out three European catchments (Spain, Finland, France) characterised by different climate, geology, use. The objective this represent spatio-temporal dynamics at reach level mesoscale networks (between 120 350 km2). daily spatially distributed condition (flowing or dry) predicted using J2000 model coupled with random forest classification model. Observed data from sources (water measurements, photo traps, citizen science applications) used build predictive This aims evaluate impact observed dataset (sample size, spatial temporal representativity) on performance Results show hybrid approach developed allows patterns be accurately catchments, sensitivity criterion above 0.9 prediction dry events Finnish French case 0.65 Spanish study. shows value combining reduce uncertainty intermittence.

Language: Английский

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Deep learning-enhanced detection of road culverts in high-resolution digital elevation models: Improving stream network accuracy in Sweden

Journal of Hydrology Regional Studies, Journal Year: 2025, Volume and Issue: 57, P. 102148 - 102148

Published: Jan. 9, 2025

Language: Английский

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Future climate or land use? Attribution of changes in surface runoff in a typical Sahelian landscape

Comptes Rendus Géoscience, Journal Year: 2023, Volume and Issue: 355(S1), P. 411 - 438

Published: Jan. 12, 2023

In this study, the Soil and Water Assessment Tool (SWAT) model is used to assess changes in surface runoff between baseline (1995–2014) future (2031–2050) periods Tougou watershed (37km 2 ) Burkina Faso. The study uses a combination of land use maps (for current periods) bias-corrected ensemble 9 CMIP6 climate models, under two warming scenarios. An increase rainfall (13.7% 18.8%) projected, which major contributor (24.2% 34.3%). change narrative (i.e. conversion bare areas croplands) expected decrease runoff, albeit minor comparison effect change. Similar findings are observed for annual maximum runoff. This sheds light on need consider simultaneously framing water management policies. Dans cette étude, le modèle agro-éco-hydrologique SWAT est utilisé pour évaluer les changements dans l’écoulement de entre la période référence 1995–2014 et 2031–2050 sur bassin versant au Cette étude utilise une combinaison cartes d’états (pour actuelle future) un corrigé modèles climatiques issus des simulations CMIP6, sous deux scénarios réchauffement. Une augmentation précipitations (de 13,7 % à 18,8 %) prévue, ce qui principal facteur contribuant l’augmentation écoulements (24,2 34,3 %). Les projetés états (principalement surfaces dégradées en sols cultivés) devrait entraîner diminution surface, toutefois proportions plus faibles comparaison effets du climat futur. Des résultats similaires sont observés lécoulement maximal annuel. met lumière nécessité prendre compte simultanément futur l’élaboration politiques futures gestion l’eau.

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Spatial and temporal patterns of flow intermittency in a Mediterranean basin using the SWAT+ model

Hydrological Sciences Journal, Journal Year: 2022, Volume and Issue: 68(2), P. 276 - 289

Published: Dec. 6, 2022

Non-perennial rivers and streams are ubiquitous. Nonetheless, our understanding of their hydrological patterns is minimal. Hydrological models powerful tools to study characterize patterns, but few can simulate extremes such as non-flow events. We aimed capture accurately the flow intermittency spatial temporal in a Mediterranean river basin with restructured Soil Water Assessment Tool (SWAT+). calibrated model using multi-objective optimization algorithm data from two gauging stations mainstream for period 2000–2020. Furthermore, we validated simulations against stage series at 14 stations. The results indicated that simulates low flows period. observed significant variation both space time remarkable inter-annual variability. also an increase over

Language: Английский

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Local Topography and Streambed Hydraulic Conductivity Influence Riparian Groundwater Age and Groundwater‐Surface Water Connection

Water Resources Research, Journal Year: 2023, Volume and Issue: 59(9)

Published: Sept. 1, 2023

Abstract The western U.S. is experiencing increasing rain to snow ratios due climate change, and scientists are uncertain how changing recharge patterns will affect future groundwater‐surface water connection. We examined watershed topography streambed hydraulic conductivity impact groundwater age stream discharge at eight sites along a headwater within the Manitou Experimental Forest, CO USA. To do so, we measured: (a) continuous discharge/level specific from April November 2021; (b) biweekly chemistry; (c) chlorofluorocarbons tritium in spring fall; (d) conductivity; (e) local slope. used chemistry data calculate fluorite saturation states that were inform end‐member mixing analysis of streamflow source. then combined chlorofluorocarbon estimate composition riparian groundwater. Our suggest drying more probable where slope steep high. In these areas, source shifted seasonally, as indicated by increases, observed high fraction streamflow, primarily interflow adjacent hillslopes. contrast, flat low, likely persist was seasonally constant buffered storage alluvial sediments. Groundwater paired with characterization subsurface characteristics enabled identification controls on patterns.

Language: Английский

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Pulse, Shunt and Storage: Hydrological Contraction Shapes Processing and Export of Particulate Organic Matter in River Networks

Ecosystems, Journal Year: 2022, Volume and Issue: 26(4), P. 873 - 892

Published: Dec. 12, 2022

Abstract Streams and rivers act as landscape-scale bioreactors processing large quantities of terrestrial particulate organic matter (POM). This function is linked to their flow regime, which governs residence times, shapes reactivity controls the amount carbon (C) exported atmosphere coastal oceans. Climate change impacts regimes by increasing both flash floods droughts. Here, we used a modelling approach explore consequences lateral hydrological contraction, that is, reduction wet portion streambed, for POM decomposition transport at river network scale. Our model integrates seasonal leaf litter input generator POM, transient storage on dry streambed portions with associated ensuing changes in reactivity, dynamics through dendritic network. Simulations showed from its average increased due combination (1) low while stored streambeds, (2) shunting during flashy events. The sensitivity analysis further supported high contraction leads higher export regardless coefficient values, fresh differences between under conditions. study incorporates areas into pulse-shunt concept (Raymond others Ecology 97(1):5–16, 2016. https://doi.org/10.1890/14-1684.1 ), providing mechanistic framework testable predictions about storage, fluvial networks.

Language: Английский

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Measuring zero water level in stream reaches: A comparison of an image‐based versus a conventional method

Hydrological Processes, Journal Year: 2022, Volume and Issue: 36(8)

Published: Aug. 1, 2022

Abstract A limited number of gauging stations, especially for nested catchments, hampers a process understanding the interaction between streamflow, groundwater and water usage during drought. Non‐commercial measurement devices can help overcome this lack monitoring, but they need to be thoroughly tested. The Dreisam River in South‐West Germany was affected by several hydrological drought events from 2015 2020 which parts main stream tributaries fell dry. Therefore it provided useful case study area flexible longitudinal quality quantity monitoring network. Among other measurements setup employs an image‐based method with QR codes as fiducial marker. In order assess under conditions QR‐code based level loggers (WLL) deliver data according scientific standards, we compared its performance conventional capacitive WLL. results 20 stations reveal that riverbed dry >50% at locations even >70% most severely July August 2020, north western catchment being concerned. Highly variable drying patterns reaches emerged monitoring. found valuable identification validation zero occurrences. Nevertheless, simple image processing approach (based on automatic thresholding algorithm) did not compensate errors due natural technical setup. Our findings highlight complexity environments is major challenge when working methods.

Language: Английский

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Deriving transmission losses in ephemeral rivers using satellite imagery and machine learning

Hydrology and earth system sciences, Journal Year: 2023, Volume and Issue: 27(3), P. 703 - 722

Published: Feb. 9, 2023

Abstract. Transmission losses are the loss in flow volume of a river as water moves downstream. These provide crucial ecosystem services, particularly ephemeral and intermittent systems. can be quantified at many scales using different measurement techniques. One most common methods is differential gauging two locations. An alternative method for non-perennial rivers to replace downstream location by visual assessments wetted length on satellite images. The transmission then calculated gauged upstream divided length. We used this approach estimate Selwyn River (Canterbury, New Zealand) 147 images collected between March 2020 May 2021. drying front was verified field six occasions seven campaigns were conducted ground-truth estimated from point data obtained lengths train an ensemble random forest models predict continuous hourly time series their uncertainties. Our results show that ranged 0.25 0.65 m3s-1km-1 during 1-year study period. However, shortly after flood peak could reach up 1.5 m3s-1km-1. enabled us improve our understanding groundwater–surface interactions valuable support management. argue framework easily adapted other longer series.

Language: Английский

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