Inferring drivers of nitrate and sediment event dynamics from hysteresis metrics for two large agricultural watersheds DOI Creative Commons
Oladipo Bolade, Amy T. Hansen

Hydrological Processes, Journal Year: 2023, Volume and Issue: 37(9)

Published: Aug. 31, 2023

Abstract Excess nitrate and sediment, mobilized by precipitation events transported into surface waters, is a global water quality challenge. Recent advances in high‐frequency situ monitoring sensors have created opportunities to investigate constituent concentration dynamics during short‐term hydrological changes. In this study, we characterized the event‐scale variability of () turbidity (a surrogate for sediment transport) two large agricultural watersheds Upper Mississippi River Basin using hysteresis loop characteristics determine sources dominant transport mechanisms. We then applied factor analysis detect variable groupings thus controls on dynamics. observed consistent counterclockwise patterns between watersheds. This was indicative distal contributions and/or late‐event mobilization flushing, which controlled event hydrology (such as, duration magnitude discharge). However, loops indicated different delivery behaviours The smaller watershed with more diverse land use demonstrated clockwise indicating early flushing or rapidly responding pathways. time lag discharge peaks identified as driver site. contrast, larger showed dilution versus well pathways events. driven peak range demonstrating an increase stream power scale influenced at site that switched behaviour. result critical management, especially context changing climate further underscores utility data offer deep insights processes contaminant delivery.

Language: Английский

Chesapeake legacies: the importance of legacy nitrogen to improving Chesapeake Bay water quality DOI Creative Commons
Sandy Y. Chang, Qian Zhang, D. Byrnes

et al.

Environmental Research Letters, Journal Year: 2021, Volume and Issue: 16(8), P. 085002 - 085002

Published: June 22, 2021

Abstract In the Chesapeake Bay, excess nitrogen (N) from both landscape and atmospheric sources has for decades fueled algal growth, disrupted aquatic ecosystems, negatively impacted coastal economies. Since 1980s, Bay Program partners have worked to implement a wide range of measures across region—from upgrading wastewater treatment plants implementation farm-level best management practices—to reduce N fluxes Bay. Despite widespread such notable reductions in inputs, water quality region been slow improve. Such lack response some cases attributed legacies—accumulations surplus soils groundwater—that can contribute time lags between conservation improvements quality. Here, we use ELEMeNT-N modeling framework explore role legacy slowing loading provide estimates required meet goals nine major tributary watersheds. Our results first show that recent be decreases magnitudes began occur 1970s will continue coming decades. Future simulations suggest that, even with no additional changes current practices, loads by 25% nearly met within next two The present also achieving may vary considerably individual study watersheds, longest lag times being found highly agricultural Choptank watershed, where remain high remains control on

Language: Английский

Citations

58
Predicting Redox Conditions in Groundwater at a National Scale Using Random Forest Classification DOI Creative Commons
Anthony J. Tesoriero, Susan A. Wherry, Danielle I. Dupuy

et al.

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: 58(11), P. 5079 - 5092

Published: March 7, 2024

Redox conditions in groundwater may markedly affect the fate and transport of nutrients, volatile organic compounds, trace metals, with significant implications for human health. While many local assessments redox have been made, spatial variability reaction rates makes determination at regional or national scales problematic. In this study, were predicted contiguous United States using random forest classification by relating measured water quality data from over 30,000 wells to natural anthropogenic factors. The model correctly oxic/suboxic 78 79% samples out-of-bag hold-out sets, respectively. Variables describing geology, hydrology, soil properties, hydrologic position among most important factors affecting likelihood oxic groundwater. Important variables tended relate aquifer recharge, travel time, prevalence electron donors, which are key drivers Partial dependence plots suggested that decreased sharply as streams approached gradually depth below table increased. probability increased base flow index values increased, likely due well-drained soils geologic materials high areas. topographic wetness (TWI) decreased. High occur areas a propensity standing overland flow, limit delivery dissolved oxygen recharge; higher TWI also tend discharge areas, contain long times. A second was developed predict elevated manganese (Mn) concentrations (i.e., ≥50 μg/L). Mn relied on same be used identify where Mn-reducing there is an risk domestic supplies concentrations. Model predictions produced study help regions country vulnerability stream groundwater-derived contaminants.

Language: Английский

Citations

15
Nitrate concentrations predominantly driven by human, climate, and soil properties in US rivers DOI
Kayalvizhi Sadayappan, Devon Kerins, Chaopeng Shen

et al.

Water Research, Journal Year: 2022, Volume and Issue: 226, P. 119295 - 119295

Published: Oct. 24, 2022

Language: Английский

Citations

37
Random forest-based modeling of stream nutrients at national level in a data-scarce region DOI Creative Commons
Holger Virro, Alexander Kmoch,

Marko Vainu

et al.

The Science of The Total Environment, Journal Year: 2022, Volume and Issue: 840, P. 156613 - 156613

Published: June 11, 2022

Nutrient runoff from agricultural production is one of the main causes water quality deterioration in river systems and coastal waters. Water modeling can be used for gaining insight into issues order to implement effective mitigation efforts. Process-based nutrient models are very complex, requiring a lot input parameters computationally expensive calibration. Recently, ML approaches have shown achieve an accuracy comparable process-based even outperform them when describing nonlinear relationships. We observations 242 Estonian catchments, amounting 469 yearly TN 470 TP measurements covering period 2016-2020 train random forest (RF) predicting annual N P concentrations. total 82 predictor variables, including land cover, soil, climate topography applied feature selection strategy reduce number dependent features models. The SHAP method was deriving most relevant predictors. performance our previous Baltic region with model having R2 score 0.83 0.52, respectively. However, as data easier obtain, offer superior applicability areas, where availability insufficient approaches. Therefore, enable give robust estimation losses at national level allows capture spatial variability which turn enables provide decision-making support regional management plans.

Language: Английский

Citations

33
Hydrologic regimes drive nitrate export behavior in human-impacted watersheds DOI Creative Commons
Galen Gorski, Margaret Zimmer

Hydrology and earth system sciences, Journal Year: 2021, Volume and Issue: 25(3), P. 1333 - 1345

Published: March 18, 2021

Abstract. Agricultural watersheds are significant contributors to downstream nutrient excess issues. The timing and magnitude of mobilization in these driven by a combination anthropogenic, hydrologic, biogeochemical factors that operate across range spatial temporal scales. However, how, when, where complex drive has previously been difficult capture with low-frequency or spatially limited data sets. To address this knowledge gap, we analyzed daily nitrate concentration (c) discharge (Q) for 4-year period (2016–2019) from five nested, agricultural the midwestern United States contribute loads Gulf Mexico. These records allow us investigate patterns at resolution not possible. span two distinct landforms shaped differences glacial history, resulting natural soil properties necessitated different drainage infrastructure study area. export under hydrologic conditions, partitioned hydrograph into stormflow baseflow periods examined those separately through analysis their concentration–discharge (c–Q) relationships on annual, seasonal, event timescales. Stormflow showed consistent chemostatic all seasons, while seasonally dynamic c–Q patterns. Baseflow exhibited chemodynamic conditions summer fall more winter spring, suggesting water source contributions during were nonstationary. behavior was low-flow, low-NO3- which in-stream near-stream biological processing likely moderated NO3- concentrations. Additionally, inputs deeper groundwater longer residence times lower-NO3- contributed stream, particularly larger watersheds. watersheds, but linked intensity agriculture density built infrastructure, associated higher This suggests way humans replumb subsurface response geologic implications connectivity, homogenization areas, and, subsequently, both stormflow. Our also anomalous flow greatly influenced overall patterns, high-resolution multiple scales is critical when interpreting seasonal annual

Language: Английский

Citations

37
Legacy nitrate and trace metal (Mn, Ni, As, Cd, U) pollution in anaerobic groundwater: Quantifying potential health risk from “the other nitrate problem” DOI
Thomas Riedel,

Christine Kübeck,

Markus Quirin

et al.

Applied Geochemistry, Journal Year: 2022, Volume and Issue: 139, P. 105254 - 105254

Published: Feb. 26, 2022

Language: Английский

Citations

28
Sources and seasonal variations of nitrate in the coastal multiple-aquifer groundwater of Beihai, southern China DOI
Ya Wu,

Huaiqing Liu,

Hongxin Zhang

et al.

Journal of Contaminant Hydrology, Journal Year: 2024, Volume and Issue: 262, P. 104308 - 104308

Published: Jan. 26, 2024

Language: Английский

Citations

5
Occurrence and distribution of atrazine in groundwater from agricultural areas in China DOI

Shengpin Li,

Fuyang Huang,

Hai-Tao Piao

et al.

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 955, P. 177161 - 177161

Published: Oct. 30, 2024

Language: Английский

Citations

5
Influence of precipitation event magnitude on baseflow and coastal nitrate export for Prince Edward Island, Canada DOI Creative Commons
Igor Pavlovskii, Yefang Jiang, Serban Danielescu

et al.

Hydrological Processes, Journal Year: 2023, Volume and Issue: 37(5)

Published: April 27, 2023

Abstract The export of anthropogenic nitrate to coastal waters, which depends on the interplay between many factors such as land use and meteorological forcing, is a rising concern in regions world. present study investigates effect precipitation event magnitude baseflow associated groundwater‐driven Prince Edward Island, Canada. Twenty‐year time‐series precipitation, stream flow, groundwater levels across island were analysed establish three‐way relationship level rise, increase along hydrological response pathway this setting. analysis was performed by extracting responses for selected subset relatively isolated events. results reveal non‐linear change that also observed events with hurricanes post tropical storms. A streamflow concentrations during Hurricane Dorian's passage (September 2019) used evaluate relevance these findings export. data show increases after heavy have limited impact concentrations, but result substantial sustained (calculated multiplying concentration flow). These observations are consistent recharge‐induced water table rise leading increased hydraulic gradients drive discharge shallow nitrate‐containing groundwater. Due similarity processes governing flow sea streams, can be gain insights into impacts direct waters. On applies at least 13% island's surface area closer ocean than any likely feeds submarine pathways.

Language: Английский

Citations

12
Long-term trends in nitrate and chloride in streams in an exurban watershed DOI
Emma Skye Castiblanco, Peter M. Groffman, J. M. Duncan

et al.

Urban Ecosystems, Journal Year: 2023, Volume and Issue: 26(3), P. 831 - 844

Published: Feb. 8, 2023

Language: Английский

Citations

11