scholarly journals Simulator for Hydrologic Unstructured Domains (SHUD v1.0): numerical modeling of watershed hydrology with the finite volume method

2020 ◽  
Vol 13 (6) ◽  
pp. 2743-2762 ◽  
Author(s):  
Lele Shu ◽  
Paul A. Ullrich ◽  
Christopher J. Duffy
Keyword(s):  
Groundwater Flow ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Overland Flow ◽  
Unsaturated Flow ◽  
Snow Accumulation ◽  
Time Step ◽  
Channel Network ◽  
Hydrologic Processes ◽  
Volume Method

Abstract. Hydrologic modeling is an essential strategy for understanding and predicting natural flows, particularly where observations are lacking in either space or time or where complex terrain leads to a disconnect in the characteristic time and space scales of overland and groundwater flow. However, significant difficulties remain for the development of efficient and extensible modeling systems that operate robustly across complex regions. This paper introduces the Simulator for Hydrologic Unstructured Domains (SHUD), an integrated, multiprocess, multiscale, flexible-time-step model, in which hydrologic processes are fully coupled using the finite volume method. SHUD integrates overland flow, snow accumulation/melt, evapotranspiration, subsurface flow, groundwater flow, and river routing, thus allowing physical processes in general watersheds to be realistically captured. SHUD incorporates one-dimensional unsaturated flow, two-dimensional groundwater flow, and a fully connected river channel network with hillslopes supporting overland flow and baseflow. The paper introduces the design of SHUD, from the conceptual and mathematical description of hydrologic processes in a watershed to the model's computational structures. To demonstrate and validate the model performance, we employ three hydrologic experiments: the V-catchment experiment, Vauclin's experiment, and a model study of the Cache Creek Watershed in northern California. Ongoing applications of the SHUD model include hydrologic analyses of hillslope to regional scales (1 m2 to 106 km2), water resource and stormwater management, and interdisciplinary research for questions in limnology, agriculture, geochemistry, geomorphology, water quality, ecology, climate and land-use change. The strength of SHUD is its flexibility as a scientific and resource evaluation tool where modeling and simulation are required.

scholarly journals Solver for Hydrologic Unstructured Domain (SHUD): Numerical modeling of watershed hydrology with the finite volume method

2020 ◽  
Author(s):  
Lele Shu ◽  
Paul A. Ullrich ◽  
Christopher J. Duffy
Keyword(s):  
Groundwater Flow ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Hydrological Modeling ◽  
Overland Flow ◽  
Unsaturated Flow ◽  
Regional Scale ◽  
Snow Accumulation ◽  
Hydrological Processes ◽  
Volume Method

Abstract. Hydrological modeling is an essential strategy for understanding natural flows, particularly where observations are lacking in either space or time, or where topographic roughness leads to a disconnect in the characteristic timescales of overland and groundwater flow. Consequently, significant opportunities remain for the development of extensible modeling systems that operate robustly across regions. Towards the development of such a robust hydrological modeling system, this paper introduces the Solver for Hydrological Unstructured Domain (SHUD), an integrated multi-process, multi-scale, multi-timestep hydrological model, in which hydrological processes are fully coupled using the Finite Volume Method. The SHUD integrates overland flow, snow accumulation/melting, evapotranspiration, subsurface and groundwater flow, and river routing, while realistically capturing the physical processes in a watershed. The SHUD incorporates one-dimension unsaturated flow, two-dimension groundwater flow, and river channels connected with hillslopes via overland flow and baseflow. This paper introduces the design of SHUD, from the conceptual and mathematical description of hydrological processes in a watershed to computational structures. To demonstrate and validate the model performance, we employ three hydrological experiments: the V-Catchment experiment, Vauclin's experiment, and a study of the Cache Creek Watershed in northern California, USA. Possible applications of then SHUD model include hydrological studies from the hillslope scale to regional scale, water resource and stormwater management, and coupling research with related fields such as limnology, agriculture, geochemistry, geomorphology, water quality, and ecology, climatic and landuse change. In general, SHUD is a valuable scientific tool for any modeling task involving simulating and understanding the hydrological response.

Post Wildfire Debris Flow and Flood Analysis of the September 2020 Badger Fire in the Trapper Creek and Rock Creek Watersheds, Idaho, USA.

2021 ◽  
Author(s):  
Stephen Turnbull ◽  
Nawa Pradhan ◽  
Ian Floyd
Keyword(s):  
Debris Flow ◽  
Finite Volume ◽  
Overland Flow ◽  
Frozen Ground ◽  
Channel Network ◽  
Hydrologic Analysis ◽  
Flood Analysis ◽  
Model Equations ◽  
Volume Method ◽  
Parameter Values

<p>There are several different infiltration, overland flow routing, and channel routing schemes that can be used in conjunction with recommended hydrodynamic and infiltration parameter values, which are found within the literature, to provide critical flooding assessments for stakeholders and decision makers.  We focus on post wildfire debris flow and flood analysis in two tributaries of the Snake River in Idaho, Trapper Creek and Rock Creek.  The Badger Fire started on September 12, 2020 in the Sawtooth National Forest in Idaho, USA, and burned sub-alpine fir, lodgepole pine, juniper, mountain brush and grass communities, in the upper part of both the Trapper Creek and Rock Creek watersheds.  Trapper Creek has a U.S. Geological Gaging station, and there are two snow gaging sites available.   The biggest concern for flooding and debris flow is the result of a wintertime rain-on-snow event, which resulted in the largest storm in the gaging record period.    </p><p>To estimate runoff in ungaged stream locations, existing process-based hydrodynamic models can be applied in a distributed form to solve the governing equations for mass, momentum and energy in a spatially explicit way. The purpose of this study is to predict potentially inundated land areas as a result of a rain-on-snow event, using the data in the gages basin to provide flood analysis information for both the gaged (Trapper Creek) and ungaged watershed (Rock Creek).  Rain-on-snow events are rainfall events that occur on the snowpack and frozen ground, resulting in a larger magnitude and volume of streamflow.  To predict these flows, Gridded Surface Subsurface Hydrologic Analysis (GSSHA) watershed models are prepared and calibrated to simulate rain-on-snow events in both watersheds.  The runoff generated from a two dimensional overland flow grid is transferred over land with a finite volume numerical method into a one dimensional channel network.  The channel network also uses a finite volume method.    The consistency in the identified range of the parametric values and their physical applicability make GSSHA an ideal candidate for this study, as the model equations provide a methods to evaluate a rain-on-snow event.</p>

Finite Volume Method for Well-Driven Groundwater Flow

2011 ◽  
pp. 361-368
Author(s):  
Milan Dotlić ◽  
Dragan Vidović ◽  
Milan Dimkić ◽  
Milenko Pušić ◽  
Jovana Radanović
Keyword(s):  
Groundwater Flow ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Volume Method

Evaluation of numerical diffusion of the finite volume method when modelling surface waves

2019 ◽  
pp. 106-119
Author(s):  
Елена Сергеевна Тятюшкина ◽  
Андрей Сергеевич Козелков ◽  
Андрей Александрович Куркин ◽  
Вадим Викторович Курулин ◽  
Валентин Робертович Ефремов ◽  
...  
Keyword(s):  
Finite Volume Method ◽  
Finite Volume ◽  
Calculation Method ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Time Step ◽  
Navier Stokes Equations ◽  
Numerical Diffusion ◽  
Volume Method

Обсуждается применение метода конечных объемов при решении уравнений Навье-Стокса для моделирования поверхностных волн. Сформулирована задача о распространении поверхностных волн, которая используется для оценки численной диффузии в решении уравнений Навье-Стокса. Предлагается методика оценки численной диффузии, выражаемой коэффициентом уменьшения амплитуды волны при прохождении ею одной своей длины (коэффициентом затухания). Дана оценка размеров сетки и шага по времени, выраженных в безразмерных величинах относительно параметров волны, необходимых для обеспечения приемлемого значения коэффициента затухания. Показана степень влияния каждого из сеточных параметров на увеличение коэффициента затухания. The application of numerical simulation methods based on the solution of the full three-dimensional Navier-Stokes equations for modelling of wave propagation on the water surface requires the construction of a grid model containing countable nodes throughout the entire volume of water medium. Insufficient grid resolution leads to insufficient detailing of the fields of velocity and pressure, as well as volume fraction of the liquid, which increases the numerical diffusion of the method and, ultimately, leads to an underestimation of oscillation amplitudes of the medium. A large time step also results in a “blurring” of the solution and significantly reduces its stability, especially when using the schemes which compress the front of the media interface. This paper presents the results of an assessment of acceptable grid sizes and time steps expressed in dimensionless parameters with respect to the wave parameters necessary to ensure accuracy of the solution sufficient for geophysical applications. The estimate is given for the method of calculating three-dimensional multiphase flows with a free surface based on solving the Navier-Stokes equations in a one-velocity approximation based on a completely implicit connection between velocity and pressure using the finite volume method. The finite volume method for the numerical solution of the Navier-Stokes equations is implemented for use on arbitrary unstructured grids. The methodology for estimation of numerical diffusion of the calculation method is proposed. This estimation is expressed as a percentage of the wave amplitude decrease at the distance equal to the one wavelength. In turn the methodology is based on the parameters entered to estimate the acceptable grid sizes and time step for the calculation method. Based on the described methodology, the results of the estimation of the grid resolution in the horizontal and vertical directions, the estimation of the time step, and the evaluation of the influence of the discretization scheme of the convective term are presented.

An integrated algorithm for hypersonic fluid–thermal–structural analysis of aerodynamically heated cylindrical leading edge

2019 ◽  
Vol 233 (14) ◽  
pp. 5177-5191 ◽  
Author(s):  
Jiawei Li ◽  
Jiangfeng Wang
Keyword(s):  
Structural Analysis ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Maximum Temperature ◽  
Aerodynamic Heating ◽  
Hypersonic Vehicles ◽  
Time Step ◽  
Heated Cylinder ◽  
Leading Edges ◽  
Volume Method

The accurate and efficient prediction of the fluid–thermal–structural performance of thermal protection systems on hypersonic vehicles to protect against severe aerodynamic heating is attracting increasing worldwide attention. In this paper, a new integrated fluid-structural-thermal investigation based on the finite volume method is proposed to study the thermal behavior of aerodynamically heated cylinder leading edges in hypersonic flows. A unified integral equation system is developed based on the governing equations for the physical processes of aerodynamic heating and structural heat transfer, which is resolved by using an up-wind finite volume method and a new two-thermal-resistance model in one integrated, vectorized computer program. To demonstrate its capability and reliability, applications for steady/unsteady fluid–thermal–structural analysis are demonstrated on aerodynamically heated cylinder leading edges at Ma 6.47. The results show that the steady maximum temperature of the cylinder can reach approximately 648 K at the stagnation point, and the unsteady results are in good agreement with the experimental data and related references. Compared with the partitioned approach, the integrated method shows better computational stability with relatively small sensitivity to mesh scale and time step, reducing the computation time for the same unsteady case by approximately 50%. The present study indicates that the integrated approach has potential for significant improvements and efficiency in predicting long-endurance fluid-structural-thermal problems of hypersonic vehicles.

scholarly journals Finite volume method solution of pollutant transport in catchment sheet flow

2013 ◽  
Vol 45 (2) ◽  
pp. 182-189
Author(s):  
Gokmen Tayfur ◽  
Zhiguo He ◽  
Qihua Ran
Keyword(s):  
Finite Volume Method ◽  
Finite Volume ◽  
Active Layer ◽  
Overland Flow ◽  
Transport Model ◽  
Pollutant Transport ◽  
Water Volume ◽  
Sheet Flow ◽  
Advection Diffusion Equation ◽  
Volume Method

A finite volume numerical method was employed in the solution of two-dimensional pollutant transport in catchment sheet flow. The full dynamic wave constituted the sheet flow while the advection–diffusion equation with sink/source terms was the pollutant transport model. It is assumed that the solute in the surface active layer is uniformly distributed and the exchange rate of the solute between the active layer and overland flow are proportional to the difference between the concentrations in soil and water volume. Decrease of the solute transfer rate in the active surface layer caused by the transfer of solutes from soil to the overlying runoff is assumed to follow an exponential law. The equations governing sheet flow and pollutant transport are discretized using the finite volume method in space and an implicit backward difference scheme in time. The model was subjected to several numerical tests involving varying microtopographic surface, roughness, and infiltration. The results revealed that spatially varying microtopography plays an important role unlike the roughness and infiltration with respect to the total pollutant rate from the outlet of a catchment.

Simulation of sediment transportation on Natorsa Creek by RiverFlow2D and SRH-2D

2020 ◽  
Author(s):  
Po-Nien Su
Keyword(s):  
Finite Volume Method ◽  
Finite Volume ◽  
Operation Time ◽  
Absolute Error ◽  
Field Investigation ◽  
Time Interval ◽  
Time Step ◽  
Sediment Size ◽  
Sediment Transportation ◽  
Volume Method

<p>In recent years, two-dimensional sediment transportation on movable bed models have been widely used in hydraulic engineering. Because of different assumptions, each model has its own feasibility on specified issues and areas. The SRH-2D model is an implicit method of the finite-volume method without CFL stability conditions, and requires more calculations than the explicit one at each time step. On the other hand, RiverFlow2D is an explicit method of finite-volume method with CFL conditions and saves much more time. In order to compare the results from these two software, a case study of Natorsa Creek, Kaohsiung, Taiwan, is carried out on the sensitivity analysis and different structure setups associated with rainfall data, water level record and DTM. The principle results are as following: This study uses average absolute error (MAE) and mean square root error (RSML) to investigate the sensitivities of SRH-2D and RiverFlow2D models and finds out the operation time increased with shorter time interval. Although SRH-2D supports three formulas while RiverFlow2D supports ten, it takes more factors into account like secondary flow, sediment size distribution, and the bed armoring effect. The simulation of scour-and-fill condition by these two models has shown similar result. However, there still exists small discrepancy between software simulation and field investigation.</p>

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