Continental-scale analysis of shallow and deep groundwater contributions to streams

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: March 4, 2021

Abstract Groundwater discharge generates streamflow and influences stream thermal regimes. However, the water quality buffering capacity of groundwater depends on aquifer source-depth. Here, we pair multi-year air temperature signals to categorize 1729 sites across continental United States as having major dam influence, shallow or deep signatures, lack pronounced (atmospheric) signatures. Approximately 40% non-dam have substantial contributions indicated by characteristic paired signal metrics. Streams with signatures account for half all signature show reduced baseflow a higher proportion warming trends compared These findings align theory that is more vulnerable increase depletion. atmospheric tend drain watersheds low slope greater human disturbance, indicating stream-groundwater connectivity in populated valley settings.

Language: Английский

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Geomorphic and Sedimentary Effects of Modern Climate Change: Current and Anticipated Future Conditions in the Western United States

Reviews of Geophysics, Journal Year: 2020, Volume and Issue: 58(4)

Published: Oct. 24, 2020

Abstract Hydroclimatic changes associated with global warming over the past 50 years have been documented widely, but physical landscape responses are poorly understood thus far. Detecting sedimentary and geomorphic signals of modern climate change presents challenges owing to short record lengths, difficulty resolving in stochastic natural systems, influences land use tectonic activity, long‐lasting effects individual extreme events, variable connectivity sediment‐routing systems. We review existing literature investigate nature extent change, focusing on western United States, a region generally high relief sediment yield likely be sensitive climatic forcing. Based fundamental theory empirical evidence from other regions, we anticipate climate‐driven slope stability, watershed yields, fluvial morphology, aeolian mobilization States. find for recent stability increased dune dust whereas yields morphology linked more commonly nonclimatic drivers will require better understanding how response scales disturbance, lag times hysteresis operate within distinguish relative influence feedbacks superimposed disturbances. The ability constrain rapidly progressing has widespread implications human health safety, infrastructure, water security, economics, ecosystem resilience.

Language: Английский

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Stream temperature and discharge evolution in Switzerland over the last 50 years: annual and seasonal behaviour

Hydrology and earth system sciences, Journal Year: 2020, Volume and Issue: 24(1), P. 115 - 142

Published: Jan. 10, 2020

Abstract. Stream temperature and discharge are key hydrological variables for ecosystem water resource management particularly sensitive to climate warming. Despite the wealth of meteorological data, few studies have quantified observed stream trends in Alps. This study presents a detailed analysis 52 catchments Switzerland, country covering wide range alpine lowland regimes. The influence discharge, precipitation, air temperature, upstream lakes on temperatures their temporal is analysed from multi-decadal seasonal timescales. has significantly increased over past 5 decades, with positive all four seasons. mean last 20 years +0.37±0.11 ∘C per decade resulting joint effects (+0.39±0.14 decade), (-10.1±4.6 % precipitation (-9.3±3.4 decade). For longer time period (1979–2018), +0.33±0.03 +0.46±0.03°C -3.0±0.5 -1.3±0.5 precipitation. Furthermore, we show that snow glacier melt compensates warming transient way streams. Lakes, contrary, strengthening effect downstream at elevations. Moreover, identified shown critical impacts ecological economical thresholds (the spread fish diseases usage industrial cooling), especially rivers, suggesting these waterways becoming more vulnerable increasing forcing. Resilient rivers expected become near future due reductions snow- glacier-melt inputs. A mathematical framework along necessary source code provided this paper.

Language: Английский

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Genetic-Algorithm-Optimized Sequential Model for Water Temperature Prediction

Sustainability, Journal Year: 2020, Volume and Issue: 12(13), P. 5374 - 5374

Published: July 2, 2020

Advances in establishing real-time river water quality monitoring networks combined with novel artificial intelligence techniques for more accurate forecasting is at the forefront of urban management. The preservation and improvement our impaired streams are core global challenge ensuring sustainability. This work adopted a genetic-algorithm (GA)-optimized long short-term memory (LSTM) technique to predict temperature (WT) as key indicator health state aquatic habitat, where its modeling crucial effective To knowledge, this first attempt adopt GA-LSTM WT rivers. In recent research trends, large volumes data, including temperature, conductivity, pH, turbidity, constantly being collected. Specifically, field management, provides countless opportunities understanding impairment forecasting, develop models habitat assessment purposes. main objective was reliable simple tool using advanced machine learning methods that can be used conjunction network stations proactive We proposed hybrid time series regression model forecasting. approach applied solve problems regarding window size architectural factors (number units) LSTM network. have chosen an hourly record collected over 5 years input. Furthermore, check robustness, recurrent neural (RNN) also tested benchmark performances were compared. experimental results revealed outperformed RNN basic problem determining optimal number units cell solved. concluded deep analysis.

Language: Английский

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Permafrost Promotes Shallow Groundwater Flow and Warmer Headwater Streams

Water Resources Research, Journal Year: 2020, Volume and Issue: 57(2)

Published: Dec. 12, 2020

Abstract The presence of permafrost influences the flow paths water through Arctic landscapes and thereby has potential to impact stream discharge thermal regimes. Observations from 11 headwater streams in Alaska showed that July temperatures were higher catchments with more near‐surface permafrost. We apply a fully coupled cryohydrology model investigate if on path depth could cause same pattern groundwater discharging hillslopes streams. simulates surface energy balances, snow, subsurface balances for two‐dimensional hillslope cases varying extent. find continuous have shallow twice as high rates evapotranspiration, compared no For our simulated cases, 6.7% horizontal flux moves top organic soil layers when there is permafrost, while only 0.5% without deeper permafrost‐free simulations buffer seasonal temperature extremes, so summer are highest Our results suggest thawing alters can lead decreases reductions evapotranspiration catchments. These changes importance biotic components ecosystems, however, full remains unknown.

Language: Английский

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A primer on stream temperature processes

Wiley Interdisciplinary Reviews Water, Journal Year: 2023, Volume and Issue: 10(4)

Published: Feb. 28, 2023

Abstract Stream temperature is one of the most critical factors controlling aquatic ecosystem health. Practitioners and researchers from a range fields, including biology, ecology, hydrology, engineering, watershed management, are concerned with how climate environmental changes impacting stream thermal regimes. This primer provides an introduction to various energy water exchange processes that underpin patterns small headwater streams large river systems. An overview exchanges provided, (1) advection associated hydrologic processes, at (2) stream–atmosphere interface (3) stream–bed interface. The interaction spatiotemporal variability these discussed using balance framework. A sound physical understanding appreciation complex controls governing regimes will help inform effective management strategies sustain healthy ecosystems in changing world. article categorized under: Science Water > Hydrological Processes Quality Life Nature Freshwater Ecosystems

Language: Английский

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Future water temperature of rivers in Switzerland under climate change investigated with physics-based models

Hydrology and earth system sciences, Journal Year: 2022, Volume and Issue: 26(4), P. 1063 - 1087

Published: Feb. 24, 2022

Abstract. River ecosystems are highly sensitive to climate change and projected future increase in air temperature is expected the stress for these ecosystems. Rivers also an important socio-economic factor impacting, amongst others, agriculture, tourism, electricity production, drinking water supply quality. In addition changes availability, will impact river temperature. This study presents a detailed analysis of discharge evolution over 21st century Switzerland. total, 12 catchments studied, situated both on lowland Swiss Plateau Alpine regions. The assessed using chain physics-based models forced with most recent scenarios Switzerland including low-, mid-, high-emission pathways. suitability such discussed detail recommendations improvements provided. model shown provide robust results, while remaining limitations identified. These mechanisms missing correctly simulate during summer season. A clear warming modelled century. At end (2080–2090), median annual ranges between +0.9 ∘C low-emission +3.5 catchments. seasonal scale, regions exhibits different patterns. For stronger than one winter but still moderate. catchments, only very limited winter. period maximum currently occurring mid-summer, shift earlier year by few weeks (low emission) or almost 2 months (high addition, noticeable soil due glacier snow cover decrease. All results this provided corresponding source code used paper.

Language: Английский

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Increased Terrestrial Carbon Export and CO₂ Evasion From Global Inland Waters Since the Preindustrial Era

Global Biogeochemical Cycles, Journal Year: 2023, Volume and Issue: 37(10)

Published: Oct. 1, 2023

Abstract Global carbon dioxide (CO 2 ) evasion from inland waters (rivers, lakes, and reservoirs) (C) export land to oceans constitute critical terms in the global C budget. However, magnitudes, spatiotemporal patterns, underlying mechanisms of these fluxes are poorly constrained. Here, we used a coupled terrestrial–aquatic model assess how multiple changes climate, use, atmospheric CO concentration, nitrogen (N) deposition, N fertilizer manure applications have affected riverine along terrestrial‐aquatic continuum. We estimate that terrestrial loadings, export, preindustrial period (1800s) were 1,820 ± 507 (mean standard deviation), 765 132, 841 190 Tg yr −1 , respectively. During 1800–2019, multifactorial caused an increase 25% (461 reaching 2,281 2010s, with 23% (104 this exported ocean 59% (273 being emitted atmosphere. Our results showed water recycles exports nearly half net sink into atmosphere oceans, highlighting important role balance, amount should be taken account future budgets. analysis supports view major feature cycle–the transfer ocean–has undergone dramatic change over last two centuries as result human activities.

Language: Английский

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Evaluation of the Hybrid Air2stream Model for Simulating Daily Stream Temperature During Extreme Summer Heat Wave and Autumn Drought Conditions

Hydrological Processes, Journal Year: 2025, Volume and Issue: 39(1)

Published: Jan. 1, 2025

ABSTRACT As climatic conditions change globally, so too will stream thermal regimes, with implications for water quality and habitat suitability aquatic life. Stream temperature measurements are sparse in many regions, motivating the development of models that able to extrapolate past future support decision‐making resource management. This study assesses performance air2stream, a hybrid, at‐a‐site model was developed simplify data requirements process‐based while maintaining their predictive performance. The air2stream requires only time series daily mean air discharge as input variables, calibrated 23 streams British Columbia, Canada, using recorded at Water Survey Canada gauging stations available periods record up 2020. Daily were interpolated each monitoring site from ERA‐5 gridded surface product. Air2stream validated years 2021 2022, which included an extreme summer heat wave autumn drought fall outside range observed during calibration period. validation results compared those set linear mixed‐effects same predictor well simplified version uses variable. produced higher errors weather period, though its under overall remained superior statistical model. highlight importance representing hydrological processes seasonal variation predicting changing conditions.

Language: Английский

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Impact of deep learning-based dropout on shallow neural networks applied to stream temperature modelling

Earth-Science Reviews, Journal Year: 2019, Volume and Issue: 201, P. 103076 - 103076

Published: Dec. 28, 2019

Although deep learning applicability in various fields of earth sciences is rapidly increasing, shallow multilayer-perceptron neural networks remain widely used for regression problems. Despite many clear distinctions between and networks, some techniques developed may help improve models. Dropout, a simple approach to avoid overfitting by randomly skipping nodes net during each training iteration, among methodological features that made successful. In this study we give review dropout methods empirically show that, when together with early-stopping, its variant dropconnect could performance multi-layer perceptron networks. Shallow are applied streamwater temperature modelling problems six catchments, based on air temperature, river discharge declination the Sun. We found particular network architecture includes at least few hidden repeated times, reduces number models perform poorly testing data, hence improves mean performance. If inputs or very low, only disturbs training. However, need be dropped out much lower probability than case (about 1%, instead 10–50% learning), due smaller network. Larger probabilities dropping hinder convergence algorithm lead poor results both calibration data. Dropconnect turned slightly more effective dropout.

Language: Английский

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