Instructive Surprises in the Hydrological Functioning of Landscapes

Annual Review of Earth and Planetary Sciences, Journal Year: 2023, Volume and Issue: 51(1), P. 277 - 299

Published: Jan. 10, 2023

Landscapes receive water from precipitation and then transport, store, mix, release it, both downward to streams upward vegetation. How they do this shapes floods, droughts, biogeochemical cycles, contaminant the health of terrestrial aquatic ecosystems. Because many key processes occur invisibly in subsurface, our conceptualization them has often relied heavily on physical intuition. In recent decades, however, much intuition been overthrown by field observations emerging measurement methods, particularly involving isotopic tracers. Here we summarize surprises that have transformed understanding hydrological at scale hillslopes drainage basins. These forced a shift perspective process conceptualizations are relatively static, homogeneous, linear, stationary ones predominantly dynamic, heterogeneous, nonlinear, nonstationary. ▪Surprising novel measurements transforming functioning landscapes.▪Even during storm peaks, streamflow is composed mostly stored landscape for weeks, months, or years.▪Streamflow tree uptake originate different subsurface storages seasons’ precipitation.▪Stream networks dynamically extend retract as wets dries, stream reaches lose flow into underlying aquifers.

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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Improving calibration of groundwater flow models using headwater streamflow intermittence

Hydrological Processes, Journal Year: 2024, Volume and Issue: 38(6)

Published: June 1, 2024

Abstract Non‐perennial streams play a crucial role in ecological communities and the hydrological cycle. However, key parameters processes involved stream intermittency remain poorly understood. While climatic conditions, geology land use are well identified, assessment modelling of groundwater controls on streamflow intermittence challenge. In this study, we explore new opportunities to calibrate process‐based 3D flow models designed simulate hydrographic network dynamics groundwater‐fed headwaters. Streamflow measurements maps considered together constrain effective hydraulic properties aquifer hydrogeological models. The simulations were then validated using visual observations water presence/absence, provided by national monitoring France (ONDE). We tested methodology two pilot unconfined shallow crystalline catchments, Canut Nançon catchments (Brittany, France). found that both expansion/contraction required simultaneously estimate conductivity porosity with low uncertainties. calibration allowed good prediction intermittency, terms spatial extent. For studied, Nançon, is close reaching 1.5 × 10 −5 m/s 4.5 m/s, respectively. they differ more their storage capacity, estimated at 0.1% 2.2%, Lower capacity leads higher level fluctuations, shorter response times, an increase proportion intermittent reduction perennial flow. This framework for predicting headwater can be deployed improve our understanding different geomorphological, geological contexts. It will benefit from advances remote sensing crowdsourcing approaches generate observational data products high temporal resolution.

Language: Английский

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Calibration of groundwater seepage against the spatial distribution of the stream network to assess catchment-scale hydraulic properties

Hydrology and earth system sciences, Journal Year: 2023, Volume and Issue: 27(17), P. 3221 - 3239

Published: Sept. 8, 2023

Abstract. The assessment of effective hydraulic properties at the catchment scale, i.e., conductivity (K) and transmissivity (T), is particularly challenging due to sparse availability hydrological monitoring systems through stream gauges boreholes. To overcome this challenge, we propose a calibration methodology which only considers information from digital elevation model (DEM) spatial distribution network. built on assumption that groundwater system main driver controlling density extension, where perennial network reflects intersection table with topography. Indeed, seepage surface primarily controlled by topography, aquifer thickness dimensionless parameter K/R, R average recharge rate. Here, use process-based parsimonious 3D flow calibrate K/R minimizing relative distances between observed simulated generated zones. By deploying in 24 selected headwater catchments located northwestern France, demonstrate method successfully predicts extent for 80 % cases. Results show high sensitivity extension low-order streams limited impacts DEM resolution as long remains consistent observations. assuming an rate, found K values vary 1.0×10-5 1.1×10-4 m s−1, agreement local estimates derived tests independent calibrated model. With emergence global remote-sensing databases compiling high-resolution networks, approach provides new opportunities assess unconfined aquifers ungauged basins.

Language: Английский

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Extending Active Network Length Versus Catchment Discharge Relations to Temporarily Dry Outlets

Water Resources Research, Journal Year: 2024, Volume and Issue: 60(1)

Published: Jan. 1, 2024

Abstract River networks are not steady blue lines drawn in a map, since they continuously change their shape and extent response to climatic drivers. Therefore, the flowing length of rivers ( L ) corresponding catchment‐scale streamflow Q sur co‐evolve dynamically. This paper analyzes relationship between wet channel river basin, formulating general analytical model that includes case temporarily dry outlets. In particular, framework relaxes common assumption when discharge at outlet tends zero upstream approaches zero. Different expressions for law derived cases (a) perennial outlet; (b) non‐perennial dries out only whole network is dry; (c) outlet, experiences surface flow less time than other nodes. all cases, controlled by distribution specific subsurface capacity along network. For outlets, however, relation might depend on an unknown shifting factor. Three real‐world examples presented demonstrate flexibility robustness theory. Our results indicate be empirically observable if significant fraction or some reaches experience longer gauging station. The study provides basis integrating empirical data gathered diverse sites.

Language: Английский

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Diel dissolved organic matter patterns reflect spatiotemporally varying sources and transformations along an intermittent stream

Limnology and Oceanography, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 18, 2024

Abstract Stream dissolved organic matter (DOM) is a globally important carbon flux and locally control on stream ecosystems, therefore understanding controls DOM fluxes dynamics crucial at both local global scales. However, attributing process challenging because hydrological biological are integrated may vary over time throughout networks. Our objective was to assess the patterns corresponding of diel cycles through seasonal flow recession by using reach‐scale in situ sensors non‐perennial network. We identified five characteristic variations with differing phase amplitude. During snowmelt flows, were consistent among sites reflected flowpath shifts photodegradation. Evapotranspiration‐driven stage oscillations emerged two upstream sites, shaping indirectly, creating conditions for instream processing. At spring‐fed site, minimal variation observed summer whereas an intermittent reach, daily drying rewetting created biogeochemical hot moments. This research demonstrates that space, even close proximity, generating asynchronous fDOM during low illuminating processes flowpaths.

Language: Английский

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Evapotranspiration and groundwater inputs control the timing of diel cycling of stream drying during low-flow periods

Frontiers in Water, Journal Year: 2023, Volume and Issue: 5

Published: Oct. 25, 2023

Geologic, geomorphic, and climatic factors have been hypothesized to influence where streams dry, but hydrologists struggle explain the temporal drivers of drying. Few isolated role that vegetation plays in controlling timing location stream drying headwater streams. We present a distributed, fine-scale water balance through seasonal recession onset by combining spatiotemporal observations modeling flow presence/absence, evapotranspiration, groundwater inputs. Surface presence/absence was collected at fine spatial (~80 m) (15-min) scales 25 locations southwestern Idaho, USA. Evapotranspiration losses were modeled same using Simultaneous Heat Water (SHAW) model. Groundwater inputs estimated four mixing model approach. In addition, we compared high-frequency, fine-resolution riparian normalized difference index (NDVI) with status. found wetted dried on daily basis before seasonally drying, occurred when evapotranspiration outputs exceeded inputs, typically during hours peak evapotranspiration. Riparian NDVI decreased dried, ~2-week lag between response. Stream diel cycles reflect balance, may improve predictions for groundwater-supported

Language: Английский

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Nonlinear Riparian Interactions Drive Changes in Headwater Streamflow

Water Resources Research, Journal Year: 2023, Volume and Issue: 59(10)

Published: Aug. 30, 2023

Abstract As drought and wildfire frequency increase across the western United States, our ability to predict how water resources will respond these disturbances depends on understanding of feedbacks that maintain watershed function streamflow. Previous studies non‐perennial headwater streams have ranked drivers low‐flow conditions; however, there is a limited interactions between processes through which affect Here, we use stream level, soil moisture, sap flow, vapor pressure deficit data investigate ecohydrological along mountainous stream. Correlation cross‐correlation analyses variables show are (a) nonlinear (b) interconnected, suggesting assuming linearity independence each driver inadequate for quantifying interactions. To account issues causal linkages, convergent cross‐mapping (CCM) characterize influence CCM nonlinear, dynamic method has only recently been applied hydrologic systems. results reveal atmospheric losses associated with local flow driving changes in moisture streamflow ( p < 0.01) more directly than shallow moisture. These also demonstrate riparian continue subsurface flows channel corridor even after drying. This study proposes framework ecohydrologic may determine disturbance.

Language: Английский

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The Communication Distance of Non-Perennial Streams

EarthArXiv (California Digital Library), Journal Year: 2023, Volume and Issue: unknown

Published: Jan. 11, 2023

We developed Bayesian statistical approaches to assess non-perennial stream network connectivity. Our new methods allow: 1) consideration of changes both local (stream segment) and global network) connectivity over time, 2) incorporation prior information from different data sources, 3) straightforward computation the posterior distributions active length a metric called communication distance. Communication distance measures effective for movement materials, including water solutes, upstream downstream sites. posteriors require inverse-beta probability density function whose form had not been previously derived. The distribution can be used represent rarity surface presence compared perennial stream, thus clarifying bottlenecking propensities segments. As an application, we considered Murphy Creek, simple in southwestern Idaho, USA. models presence/absence 2019, priors based on existing regional USGS model predictions water. Creek probabilities were heterogeneous space likely driven by fine-scale spatial variations shallow subsurface hydraulic conductivity. Strong seasonal (spring, summer, fall) temporal differences evident network-level Specifically, lengths shorter more variable summer fall than spring. novel multimodal, platykurtic, negatively skewed spring, fall, respectively, revealing effects that varied time.

Language: Английский

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Multi-scale drivers of daily flow intermittency in a regulated desert river

Published: April 27, 2024

Abstract Fluvial ecosystems are vital for biodiversity and human welfare but face increasing threats from flow intermittency caused by climate change other activities. To better understand drivers of intermittency, we analyzed long-term spatially explicit river drying data the Rio Grande, a regulated in North American desert southwest that was historically perennial is now persistently intermittent. We examined spatial structure influences precipitation, temperature, in-channel infrastructure, discharge on using multivariate autoregressive state space (MARSS) models 12 years daily data. Our findings indicate diversion rates at dams irrigation return flows significantly occurrence factors (possibly geologic) distances ≤ 7 kilometers (km) more influential as predictors drying. Controlling temperature precipitation were not detected reach level (∼154 km) significant each subreach scales (n = 3) investigated. At all scales, temperature’s effect size exceeds 2.5 times strongest predictor Overall, process variance decreased 98% between our reach- models, suggesting scale-sensitive have great potential to accurately inform environmental management strategies aimed mitigating negative effects water extraction.

Language: Английский

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