Investigation of Scale-Dependent Groundwater/Surface-water Exchange in Rivers by Gradient Self-Potential Logging: Numerical Modeling and Field Experiments

2021 ◽  
Vol 26 (2) ◽  
pp. 83-98
Author(s):  
Scott J. Ikard ◽  
Martin A. Briggs ◽  
John W. Lane

Exchanges of groundwater and surface-water are fundamental to a wide range of water-supply and water-quality management issues but challenging to map beyond the reach scale. Waterborne gradient self-potential (SP) measurements are directly sensitive to water flow through riverbed sediments and can be used to infer exchange locations, direction (gain versus loss), scale, and relative changes, but to date applications to river corridor hydrology are limited. Numerical modeling and field experiments were therefore performed herein, each emphasizing waterborne gradient SP logging for identifying and locating focused vertical groundwater discharge (surface-water gain) and recharge (surface-water loss) in a river. Two and three-dimensional numerical models were constructed to simulate the polarities, appearances, and peak amplitudes of streaming-potential and electric-field anomalies on a riverbed and in the surface-water that were attributable to steady-state vertical fluxes of groundwater through high-permeability conduits in the riverbed. Effects of varied hydraulic length-scale of exchange and surface-water depth were tested through numerical modeling. Modeling results aided in data acquisition and interpretation for three repeated field experiments performed along a 1.5–2.0 km reach of the Quashnet River in Cape Cod, Massachusetts, where focused, meter-scale groundwater discharges occur at discrete locations within otherwise ubiquitous and more diffuse groundwater upwelling conditions. Strong gradient SP anomalies were repeatedly measured in the Quashnet River at previously confirmed locations of focused groundwater discharge, showing the efficacy of waterborne gradient SP logging in identifying and characterizing groundwater/surface water exchange dynamics at multiple river network scales.

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 458
Author(s):  
Drew C. Baird ◽  
Benjamin Abban ◽  
S. Michael Scurlock ◽  
Steven B. Abt ◽  
Christopher I. Thornton

While there are a wide range of design recommendations for using rock vanes and bendway weirs as streambank protection measures, no comprehensive, standard approach is currently available for design engineers to evaluate their hydraulic performance before construction. This study investigates using 2D numerical modeling as an option for predicting the hydraulic performance of rock vane and bendway weir structure designs for streambank protection. We used the Sedimentation and River Hydraulics (SRH)-2D depth-averaged numerical model to simulate flows around rock vane and bendway weir installations that were previously examined as part of a physical model study and that had water surface elevation and velocity observations. Overall, SRH-2D predicted the same general flow patterns as the physical model, but over- and underpredicted the flow velocity in some areas. These over- and underpredictions could be primarily attributed to the assumption of negligible vertical velocities. Nonetheless, the point differences between the predicted and observed velocities generally ranged from 15 to 25%, with some exceptions. The results showed that 2D numerical models could provide adequate insight into the hydraulic performance of rock vanes and bendway weirs. Accordingly, design guidance and implications of the study results are presented for design engineers.


Author(s):  
Esdras Babadjidé Josué Zandagba ◽  
Eric Adéchina Alamou ◽  
Ezechiel Obada ◽  
Amédée Chabi ◽  
Eliézer Iboukoun Biao ◽  
...  

Abstract. The numerical modeling of spatio-temporal evolution of lagoon has an important role in predicting the behaviour of these systems. Knowing the concentration of the pollutant field distribution in time and space contributes significantly to the prediction of exceptional phenomena. The purpose of this paper is to simulate the transport and dispersion of salt at Nokoue Lake. To this end, the 2D hydrodynamic model SMS (Surface Water Modeling System) has been used. Results showed that in flood period the freshwater inflows produce a net seaward transport, while in low water period the tides lead to periodic seaward and landward transport. The developed numerical model is useful for predicting pollutants transport in this system, for water quality management of the Nokoue Lake, and therefore, fight against eutrophication.


TAPPI Journal ◽  
2016 ◽  
Vol 15 (5) ◽  
pp. 331-335 ◽  
Author(s):  
LEBO XU ◽  
JEREMY MYERS ◽  
PETER HART

Retention of cationic dispersed rosin size was studied via turbidity measurements on stock filtrate with different alum and dispersed rosin size dosages. Stock charge characteristics were analyzed using both an analysis of charge demand determined via a streaming current detector and an evaluation of zeta potential of the fibers by streaming potential measurement. The results indicated that an optimum amount of alum existed such that good sizing retention was maintained throughout a wide range of dispersed rosin size dosages. However, when an excessive amount of alum was used and fines and colloidal particles were transitioned from anionic to cationic, the cationic size retention was reduced. Laboratory results were confirmed with a paper machine trial. All data suggested that a stock charge study was necessary to identify optimal alum dosage for a cationic dispersed rosin sizing program.


2020 ◽  
pp. 046
Author(s):  
Thierry Bergot ◽  
Pierre Bessemoulin ◽  
Claire Sarrat

La synergie entre campagnes de mesures et modélisation numérique a permis de faire fortement progresser notre compréhension des interactions sol-végétation-atmosphère. Ces progrès ont conduit à l'élaboration du modèle de surface Isba développé par Joël Noilhan et utilisé aujourd'hui encore dans les modèles de prévision opérationnelle de Météo-France. Cet article vise à illustrer l'apport des campagnes de mesures dans l'amélioration de nos connaissances des processus en surface à travers trois exemples, Hapex-Mobilhy pour l'étude du bilan hydrique, Carbo-Europe pour l'étude du bilan en carbone et l'étude du brouillard sur l'aéroport Paris-CdG pour l'influence des conditions de surface sur les nuages bas. The synergy between field experiments and numerical modeling has allowed to significantly advance our understanding of soil-vegetation-atmosphere interactions. This progress led to the ISBA surface model developed by Joël Noilhan and used today in Météo-France's operational forecasting models. This article aims to illustrate the contribution of field experiments in improving our knowledge of surface processes through three examples: Hapex-Mobilhy, Carbo-Europe, and the study of fog at Paris-CdG airport.


Weed Science ◽  
1979 ◽  
Vol 27 (5) ◽  
pp. 497-501 ◽  
Author(s):  
C. D. Boyette ◽  
G. E. Templeton ◽  
R. J. Smith

An indigenous, host-specific, pathogenic fungus that parasitizes winged waterprimrose [Jussiaea decurrens(Walt.) DC.] is endemic in the rice growing region of Arkansas. The fungus was isolated and identified asColletotrichum gloeosporioides(Penz.) Sacc. f.sp. jussiaeae(CGJ). It is highly specific for parasitism of winged waterprimrose and not parasitic on creeping waterprimrose (J. repensL. var.glabrescensKtze.), rice (Oryza sativaL.), soybeans [Glycine max(L.) Merr.], cotton (Gossypium hirsutumL.), or 4 other crops and 13 other weeds. The fungus was physiologically distinct from C.gloeosporioides(Penz.) Sacc. f. sp.aeschynomene(CGA), an endemic anthracnose pathogen of northern jointvetch[Aeschynomene virginica(L.) B.S.P.], as indicated by cross inoculations of both weeds. Culture in the laboratory and inoculation of winged waterprimrose in greenhouse, growth chamber and field experiments indicated that the pathogen was stable, specific, and virulent in a wide range of environments. The pathogen yielded large quantities of spores in liquid culture. It is suitable for control of winged waterprimrose. Winged waterprimrose and northern jointvetch were controlled in greenhouse and field tests by application of spore mixtures of CGJ and CGA at concentrations of 1 to 2 million spores/ml of each fungus in 94 L/ha of water; the fungi did not damage rice or nontarget crops.


2015 ◽  
Vol 51 (1) ◽  
pp. 198-212 ◽  
Author(s):  
Dylan J. Irvine ◽  
Roger H. Cranswick ◽  
Craig T. Simmons ◽  
Margaret A. Shanafield ◽  
Laura K. Lautz

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1331
Author(s):  
Scott Ikard ◽  
Andrew Teeple ◽  
Delbert Humberson

The Rio Grande/Río Bravo del Norte (hereinafter referred to as the “Rio Grande”) is the primary source of recharge to the Mesilla Basin/Conejos-Médanos aquifer system in the Mesilla Valley of New Mexico and Texas. The Mesilla Basin aquifer system is the U.S. part of the Mesilla Basin/Conejos-Médanos aquifer system and is the primary source of water supply to several communities along the United States–Mexico border in and near the Mesilla Valley. Identifying the gaining and losing reaches of the Rio Grande in the Mesilla Valley is therefore critical for managing the quality and quantity of surface and groundwater resources available to stakeholders in the Mesilla Valley and downstream. A gradient self-potential (SP) logging survey was completed in the Rio Grande across the Mesilla Valley between 26 June and 2 July 2020, to identify reaches where surface-water gains and losses were occurring by interpreting an estimate of the streaming-potential component of the electrostatic field in the river, measured during bankfull flow. The survey, completed as part of the Transboundary Aquifer Assessment Program, began at Leasburg Dam in New Mexico near the northern terminus of the Mesilla Valley and ended ~72 kilometers (km) downstream at Canutillo, Texas. Electric potential data indicated a net losing condition for ~32 km between the Leasburg Dam and Mesilla Diversion Dam in New Mexico, with one ~200-m long reach showing an isolated saline-groundwater gaining condition. Downstream from the Mesilla Diversion Dam, electric-potential data indicated a neutral-to-mild gaining condition for 12 km that transitioned to a mild-to-moderate gaining condition between 12 and ~22 km downstream from the dam, before transitioning back to a losing condition along the remaining 18 km of the survey reach. The interpreted gaining and losing reaches are substantiated by potentiometric surface mapping completed in hydrostratigraphic units of the Mesilla Basin aquifer system between 2010 and 2011, and corroborated by surface-water temperature and conductivity logging and relative median streamflow gains and losses, quantified from streamflow measurements made annually at 16 seepage-measurement stations along the survey reach between 1988 and 1998 and between 2004 and 2013. The gaining and losing reaches of the Rio Grande in the Mesilla Valley, interpreted from electric potential data, compare well with relative median streamflow gains and losses along the 72-km long survey reach.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Mendes ◽  
J. C. B. da Silva ◽  
J. M. Magalhaes ◽  
B. St-Denis ◽  
D. Bourgault ◽  
...  

AbstractInternal waves (IWs) in the ocean span across a wide range of time and spatial scales and are now acknowledged as important sources of turbulence and mixing, with the largest observations having 200 m in amplitude and vertical velocities close to 0.5 m s−1. Their origin is mostly tidal, but an increasing number of non-tidal generation mechanisms have also been observed. For instance, river plumes provide horizontally propagating density fronts, which were observed to generate IWs when transitioning from supercritical to subcritical flow. In this study, satellite imagery and autonomous underwater measurements are combined with numerical modeling to investigate IW generation from an initial subcritical density front originating at the Douro River plume (western Iberian coast). These unprecedented results may have important implications in near-shore dynamics since that suggest that rivers of moderate flow may play an important role in IW generation between fresh riverine and coastal waters.


Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.


2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Tebogo M. Mokgehle ◽  
Nikita T. Tavengwa

AbstractAcid mine drainage is the reaction of surface water with sub-surface water located on sulfur bearing rocks, resulting in sulfuric acid. These highly acidic conditions result in leaching of non-biodegradeable heavy metals from rock which then accumulate in flora, posing a significant environmental hazard. Hence, reliable, cost effective remediation techniques are continuously sought after by researchers. A range of materials were examined as adsorbents in the extraction of heavy metal ions from acid mine drainage (AMD). However, these materials generally have moderate to poor adsorption capacities. To address this problem, researchers have recently turned to nano-sized materials to enhance the surface area of the adsorbent when in contact with the heavy metal solution. Lately, there have been developments in studying the surface chemistry of nano-engineered materials during adsorption, which involved alterations in the physical and chemical make-up of nanomaterials. The resultant surface engineered nanomaterials have been proven to show rapid adsorption rates and remarkable adsorption capacities for removal of a wide range of heavy metal contaminants in AMD compared to the unmodified nanomaterials. A brief overview of zeolites as adsorbents and the developent of nanosorbents to modernly applied magnetic sorbents and ion imprinted polymers will be discussed. This work provides researchers with thorough insight into the adsorption mechanism and performance of nanosorbents, and finds common ground between the past, present and future of these versatile materials.


Sign in / Sign up

Export Citation Format

Share Document