Subglacial water flow inferred from stream measurements at South Cascade Glacier, Washington, U.S.A.

1992 ◽  
Vol 38 (128) ◽  
pp. 51-64 ◽  
Author(s):  
Andrew G. Fountain
Keyword(s):  
Flow System ◽  
Water Discharge ◽  
Drainage System ◽  
Base Flow ◽  
Main Stream ◽  
Drainage Basins ◽  
Glacier Surface ◽  
One Dimensional ◽  
Flow Through ◽  
Artificial Tracers

AbstractThe subglacial drainage system of South Cascade Glacier is inferred by examining how discharges of water, solutes and artificial tracers in streams draining the glacier respond to meltwater and precipitation on the glacier surface. Results indicate that the glacier is divided into three (two large and one small) drainage basins, each drained by a single stream. The positions of drainage divides on the glacier surface do not always lie directly over those at the base of the glacier. Comparisons of water discharge and cation load in each of the two main streams indicate that subglacial hydraulic processes differ between drainage basins. One stream drains from a conduit that is isolated in its lower reach from the surrounding subglacial region and receives water routed englacially from the surface. The upper reach of the conduit also receives water routed englacially from the surface as well as from a distributed subglacial flow system. The other main stream drains from a conduit coupled to a debris layer beneath the glacier. Observations of the layer in natural ice tunnels indicate that the water may flow within a thin layer of debris. A one-dimensional model of flow through the debris layer can explain both the base-flow and diurnal variations of the second main stream.

scholarly journals Subglacial water flow inferred from stream measurements at South Cascade Glacier, Washington, U.S.A.

1992 ◽  
Vol 38 (128) ◽  
pp. 51-64 ◽  
Author(s):  
Andrew G. Fountain
Keyword(s):  
Flow System ◽  
Water Discharge ◽  
Drainage System ◽  
Base Flow ◽  
Main Stream ◽  
Drainage Basins ◽  
Glacier Surface ◽  
One Dimensional ◽  
Flow Through ◽  
Artificial Tracers

Abstract The subglacial drainage system of South Cascade Glacier is inferred by examining how discharges of water, solutes and artificial tracers in streams draining the glacier respond to meltwater and precipitation on the glacier surface. Results indicate that the glacier is divided into three (two large and one small) drainage basins, each drained by a single stream. The positions of drainage divides on the glacier surface do not always lie directly over those at the base of the glacier. Comparisons of water discharge and cation load in each of the two main streams indicate that subglacial hydraulic processes differ between drainage basins. One stream drains from a conduit that is isolated in its lower reach from the surrounding subglacial region and receives water routed englacially from the surface. The upper reach of the conduit also receives water routed englacially from the surface as well as from a distributed subglacial flow system. The other main stream drains from a conduit coupled to a debris layer beneath the glacier. Observations of the layer in natural ice tunnels indicate that the water may flow within a thin layer of debris. A one-dimensional model of flow through the debris layer can explain both the base-flow and diurnal variations of the second main stream.

Certain Problems with the Application of Stochastic Diffusion Processes for the Description of Chemical Engineering Phenomena. Stochastic Model of Non-Isothermal Flow Chemical Reactor

1996 ◽  
Vol 61 (2) ◽  
pp. 242-258 ◽  
Author(s):  
Vladimír Kudrna ◽  
Libor Vejmola ◽  
Pavel Hasal
Keyword(s):  
Stochastic Model ◽  
Chemical Engineering ◽  
Diffusion Processes ◽  
Dispersion Model ◽  
Chemical Reactor ◽  
Segregation Index ◽  
One Dimensional ◽  
A Value ◽  
Isothermal Case ◽  
Flow Through

Recently developed stochastic model of a one-dimensional flow-through chemical reactor is extended in this paper also to the non-isothermal case. The model enables the evaluation of concentration and temperature profiles along the reactor. The results are compared with the commonly used one-dimensional dispersion model with Danckwerts' boundary conditions. The stochastic model also enables to evaluate a value of the segregation index.

scholarly journals Hybrid nanofluid flow through a spinning Darcy–Forchheimer porous space with thermal radiation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anwar Saeed ◽  
Muhammad Jawad ◽  
Wajdi Alghamdi ◽  
Saleem Nasir ◽  
Taza Gul ◽  
...  
Keyword(s):  
Thermal Radiation ◽  
Flow System ◽  
Thermal Characteristics ◽  
Graphical Form ◽  
Hybrid Nanofluid ◽  
Porous Space ◽  
Variable Porosity ◽  
Homotopy Analysis ◽  
Porosity And Permeability ◽  
Flow Through

AbstractThis work investigates numerically the solution of Darcy–Forchheimer flow for hybrid nanofluid by employing the slip conditions. Basically, the fluid flow is produced by a swirling disk and is exposed to thermal stratification along with non-linear thermal radiation for controlling the heat transfer of the flow system. In this investigation, the nanoparticles of titanium dioxide and aluminum oxide have been suspended in water as base fluid. Moreover, the Darcy–Forchheimer expression is used to characterize the porous spaces with variable porosity and permeability. The resulting expressions of motion, energy and mass transfer in dimensionless form have been solved by HAM (Homotopy analysis method). In addition, the influence of different emerging factors upon flow system has been disputed both theoretically in graphical form and numerically in the tabular form. During this effort, it has been recognized that velocities profiles augment with growing values of mixed convection parameter while thermal characteristics enhance with augmenting values of radiation parameters. According to the findings, heat is transmitted more quickly in hybrid nanofluid than in traditional nanofluid. Furthermore, it is estimated that the velocities of fluid $$f^{\prime}\left( \xi \right),g\left( \xi \right)$$ f ′ ξ , g ξ are decayed for high values of $$\phi_{1} ,\phi_{2} ,\,Fr$$ ϕ 1 , ϕ 2 , F r and $$k_{1}$$ k 1 factors.

Stability of Viscoelastic Channel Flow

2007 ◽  
Author(s):  
Nariman Ashrafi
Keyword(s):  
Reynolds Number ◽  
Viscosity Ratio ◽  
Weissenberg Number ◽  
Base Flow ◽  
Galerkin Projection ◽  
Large Reynolds Number ◽  
One Dimensional ◽  
Stress Effects ◽  
The Stability ◽  
The One

The nonlinear stability and bifurcation of the one-dimensional channel (Poiseuille) flow is examined for a Johnson-Segalman fluid. The velocity and stress are represented by orthonormal functions in the transverse direction to the flow. The flow field is obtained from the conservation and constitutive equations using the Galerkin projection method. Both inertia and normal stress effects are included. The stability picture is dramatically influenced by the viscosity ratio. The range of shear rate or Weissenberg number for which the base flow is unstable increases from zero as the fluid deviates from the Newtonian limit as decreases. Typically, two turning points are observed near the critical Weissenberg numbers. The transient response is heavily influenced by the level of inertia. It is found that the flow responds oscillatorily. When the Reynolds number is small, and monotonically at large Reynolds number when elastic effects are dominated by inertia.

scholarly journals Ecological Guidelines and Recommendations for Mula-Mutha Riverfront Development

2021 ◽  
Vol 32-33 (1) ◽  
Author(s):  
Swati Gole ◽  
Revati Gindi ◽  
Dhruwang Hingmire ◽  
Gurudas Nulkar
Keyword(s):  
Fresh Water ◽  
Water Flow ◽  
Base Flow ◽  
Main Stream ◽  
River Ecosystem ◽  
Water Addition ◽  
Biodiversity Indicators ◽  
Human Interventions ◽  
Guidelines And Recommendations ◽  
Riverfront Development

This paper is a case of urban river Mutha for ecological management.Over the past few decades, condition of river Mutha has deteriorated considerably. The present situation shows less of fresh water flow and lot of sewage water addition,waste dumping and foul smelling water flow. The fresh water contribution by base flow to the main stream is very negligible. The only source of fresh water is sporadic water release from Khadakwasala dam. It is irregular and in small proportion to support ecosystem functioning of the river Mutha.There is a of public debate regarding improvement in the river's condition and to correct its root cause. The disruption in the river's ecosystem is basically by human interventions. The study appeals for interdisciplinary approach with a view of environmental governance and management to solve river related problems. The focus of this study is to assess environmental impact when the river related projects being planned by Municipal authorities. The study included survey of physical changes by human interventions, in the river Mutha channel ,banks and modification of habitats hampering aquatic as well as land biodiversity. The study indicated crucial biodiversity indicators for the health of the river ecosystem. By giving grades based on both the physical conditions and biodiversity of various stretches of the river plan to improve conditions is suggested.The study created guidelines for restoration and management of Mutha river ecosystem, which may be useful for rivers especially in the urban area. This paper is based on the research project .Ecological Guidelines and Recommendations for Mula-Mutha Riverfront Development. conducted by Ecological Society.

scholarly journals Combined measurements of Subglacial Water Pressure and Surface Velocity of Findelengletscher, Switzerland: Conclusions about Drainage System and Sliding Mechanism

1986 ◽  
Vol 32 (110) ◽  
pp. 101-119 ◽  
Author(s):  
Almut Iken ◽  
Robert A. Bindschadler
Keyword(s):  
Functional Relationship ◽  
Water Pressure ◽  
Drainage System ◽  
High Water ◽  
Water Levels ◽  
Surface Velocity ◽  
Glacier Surface ◽  
Measured Velocity ◽  
Sliding Mechanism ◽  
Velocity Variations

AbstractDuring the snow-melt season of 1982, basal water pressure was recorded in 11 bore holes communicating with the subglacial drainage system. In most of these holes the water levels were at approximately the same depth (around 70 m below surface). The large variations of water pressure, such as diurnal variations, were usually similar at different locations and in phase. In two instances of exceptionally high water pressure, however, systematic phase shifts were observed; a wave of high pressure travelled down-glacier with a velocity of approximately 100 m/h.The glacier-surface velocity was measured at four lines of stakes several times daily. The velocity variations correlated with variations in subglacial water pressure. The functional relationship of water pressure and velocity suggests that fluctuating bed separation was responsible for the velocity variations. The empirical functional relationship is compared to that of sliding over a perfectly lubricated sinusoidal bed. On the basis of the measured velocity-pressure relationship, this model predicts a reasonable value of bed roughness but too high a sliding velocity and unstable sliding at too low a water pressure. The main reason for this disagreement is probably the neglect of friction from debris in the sliding model.The measured water pressure was considerably higher than that predicted by the theory of steady flow through straight cylindrical channels near the glacier bed. Possible reasons are considered. The very large disagreement between measured and predicted pressure suggests that no straight cylindrical channels may have existed.

scholarly journals ANALISA PERENCANAAN SISTEM DRAINASE DALAM UPAYA PENANGGULANGAN BANJIR DI KECAMATAN GANDUSARI KABUPATEN TRENGGALEK

2019 ◽  
Vol 2 (1) ◽  
pp. 131
Author(s):  
Rizqi Dwi Prasetyo ◽  
Yosef Cahyo ◽  
Ahmad Ridwan
Keyword(s):  
Water Discharge ◽  
Drainage System ◽  
Domestic Wastewater ◽  
Channel Height ◽  
Construction Costs ◽  
Flood Prevention ◽  
Dirty Water ◽  
Rainwater Runoff ◽  
The Cost ◽  
The Ideal

In industrial areas or densely populated settlements, generally found channels that function besides to drain rainwater as well as to discharge domestic wastewater or dirty water from households. Drainage systems are often the main problem in the occurrence of flooding. It is necessary to analyze how their performance and resistance to flooding in the District of Gandusari, Trenggalek Regency. For analysis of drainage system planning in flood prevention efforts, the authors used the Van-Breun and Mononobe calculation methods to determine the number of incoming water discharge, the ideal dimension of the channel to accommodate the inlet discharge channel, and calculate the cost budget plan (RAB) of the builder. From the analysis, results obtained a cumulative discharge of rainwater, and dirty water entering the drainage amounted to 0.4695 m3 / sec. From the calculation, the ideal dimensions of the drainage can be obtained to be able to accommodate rainwater runoff and dirty water discharge using square channels, where the 1.5 m channel height is all added to the water level of 0.2 m and 0.7 m in width 500 m. While the budget plan for the construction costs is Rp. 794,048,000.00 -Di daerah industri atau pemukiman padat penduduk umumnya ditemukan saluran yang berfungsi selain untuk mengalirkan air hujan juga sekaligus untuk pembuangan air limbah domestik ataupun air kotor dari rumah tangga. System drainase sering menjadi pokok masalah dalam terjadinya banjir, maka perlu di Analisa bagaimana kinerjanya dan ketahanan terhadap banjir di Kecamatan Gandusari Kabupaten Trenggalek. Untuk analisis perencanaan sistem drainase dalam upaya penanggulangan banjir penulis menggunakan metode perhitungan Van-Breun dan Mononobe untuk mengetahui angka debit air yang masuk, dimensi ideal saluran untuk menampung saluran debit air masuk dan menghitung rencana anggaran biaya (RAB) pembangunanya. Dari hasil analisa didapatkan debit komulatif air hujan dan air kotor yang masuk ke drainase sebesar 0.4695 m3/detik. Dari perhitungan didapatkan dimensi saluran drainase yang ideal agar mampu menampung limpasan air hujan dan debit air kotor dengan menggunakan saluran berbentuk persegi, dimana tinggi saluran 1,5 m semuanya ditambahkan dengan tinggi jagaan air sebesar 0,2 m dan lebar 0,7 m dengan panjang 500 m. Sedangkan rencana Anggaran Biaya pembangunannya sebesar Rp. 794.048.000,00,-

scholarly journals Spatial Variability Pattern of Hyporheic Exchange in a braided River

2018 ◽  
Vol 246 ◽  
pp. 01098
Author(s):  
Guangdong Wu ◽  
Xiao Zhang ◽  
Jijun Xu
Keyword(s):  
Spatial Variability ◽  
Flow System ◽  
Hyporheic Exchange ◽  
Braided River ◽  
Downward Flow ◽  
One Dimensional ◽  
Physical Mechanisms ◽  
Braided Channel ◽  
Variability Pattern ◽  
Heat As A Tracer

The streambed flux is variable in space; the spatial variability results in part from bedforms, but few works on streambed fluxes in channels with strongly abrupt varying bedforms are carried out. Heat as a tracer to delineate the streambed flux pattern has been widely adopted in numerous fields. In this paper, a braided channel with complicated topography was selected as study site, where the temperature was monitored. One-dimensional (1-D) analytical method based on the amplitude attenuation (Ar) and 1-D numerical method were used to interpret the temperature. As a result, streambed fluxes of a total of 50 sites in the braided channel are obtained. From the results we can know the magnitude and direction of streamed flow velocity are spatially variable, even within a 1-m distance. Then, this study summarizes five bedform-driven flux patterns: ① downward flow driven by the head difference between groundwater and stream, ② downward flow related to a meter-scale pool, ③ a transition from upward to downward flow associated with a centimeter-scale riffle, ④ horizontal flow in braided bars and ⑤ upward flow driven by vegetation roots. Overall, multiple physical mechanisms together contributed to the complex streambed flow system, which reflected great challenges for the scaling up of point-in-space seepage flux.

scholarly journals A multi-functional and multi-compartment constructed wetland to support urban waterway restoration

2018 ◽  
Vol 13 (4) ◽  
pp. 764-770 ◽  
Author(s):  
T. M. Adyel ◽  
M. R. Hipsey ◽  
C. Oldham
Keyword(s):  
Constructed Wetland ◽  
Flow System ◽  
Surface Flow ◽  
Base Flow ◽  
Low Flow ◽  
Nutrient Loads ◽  
Storm Events ◽  
Flow Conditions ◽  
Storm Flow ◽  
Diverse Area

Abstract This study assessed the significance of a multi-functional and multi-compartment constructed wetland (CW) implemented to restore a degraded urban waterway in Western Australia. The wetland was initially constructed as a surface flow system, then modified through the incorporation of the additional laterite-based subsurface flow system, with the potential for operation of a recirculation scheme and groundwater top-up during low water flows in summer. The CW performance was assessed by comparing nitrogen (N) and phosphorus (P) attenuation during base flow, high flow and episodic storm flow conditions. The performance varied from approximately 41% total nitrogen (TN) and 66% total phosphorus (TP) loads reduction during storm events, increasing up to 62% TN and 99% TP during low flow and summer recirculation periods. In overall, the CW attenuated about 45% TN and 65% TP loads from being delivered to the downstream sensitive river between 2009 and 2015. The CW design proved to be not only highly effective at reducing nutrient loads, but also improved the ecological services of the urban waterway by providing a diverse area for habitat and recreational activities.

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