Two-Dimensional Flood Modeling using RiverFlow2D SMS

Workshop

Reinaldo Garcia, PhDReinaldo Garcia,Hydronia LLCHydronia LLCPembroke Pines, FL

Cameron Jenkins, PECameron Jenkins, PEWEST Consultants Inc.WEST ConsultanSan Diego, CA

September 8th 2015

2015 Floodplain Management Association Annual Conference

Workshop Agenda08:30 – 08:45 Check-in, introduction, review agenda.

08:45 – 09:30 Overview of the RiverFlow2D model.

09:30 – 10:15 Introduction to SMS RiverFlow2D GUI.

10:15 – 10:30 Break.

10:30 – 12:00 Hands-on session: Setting up a RiverFlow2D SMS project.

12:00 –12:30 Comparing RiverFlow2D with other 2D models?

Flood Simulation with Autodesk®

Infraworks® 360 Project Boulder

• Autodesk-Hydronia collaboration agreement to integrate RiverFlow2D model in Autodesk® InfraWorks® 360 software

• Available as a free trial preview until Nov. 2015• Autodesk Labs site (labs.autodesk.com).

Presentation

Does it Matter Doing 2D Flood Modeling 150 Times Faster?

• Thursday 11:00 a.m. - 12:30 p.m.• Location: Celebrity H

Overview of the RiverFlow2D model

Outline

• Two-dimensional models• RiverFlow2D hydrodynamics• Hydraulic and hydrologic components• Add-on modules• Equations, boundary conditions and numerical

methods • Assumptions and limitations• Tests

One-dimensional Modeling

Q, A, V

1D Models

• WSEL is constant on each cross section• Average velocity • Velocity perpendicular to cross section• Modeler predetermines flow direction!

2D ModelingS

yxtGFU

2D Model Limitations

• Neglect vertical Accelerations

• Neglect vertical velocity• Don’t consider

secondary currents

2D Models• Structured mesh-Grid

– Velocity vectors can have any direction, or

– Velocity has predetermined directions

• Unstructured Flexible mesh (Triangles-quadrilaterals)– Velocity vectors can have any

direction

Flexible Mesh

Square vs Triangle

400,000 Triangles2,200,000 Squares

5.5 times more cells

RiverFlow2D Model

• Combined Hydrologic-Hydraulic model

• Unstructured flexible mesh• Robust dry-wet bed algorithm• Finite-Volume numerical engine• Ensures stability supercritical and

subcritical regimes• Extensively validated in a broad

range of real-world projects• Add-on Modules: ST, PL, MD• Hydraulic structures• Aquaveo SMS GUI • GPU version.

RiverFlow2D Equations

SyxtGFU

Hydraulic Components

• Culvert calculations using FHWAformulation

• Weirs (levees and sound walls)• Internal rating tables• Sources and sinks • Bridges • Gates• Wind stress

RiverFlow2D BRIDGES Component CapabilitiesArbitrary plan alignment

Complex bridge geometry

Free surface flow

Pressure flow

Overtopping

Combined pressure flow and overtopping

Implementation of Bridges in 2D

• Friction term

• Pressure variation due to bed slope

• Bed shear stress

• Local energy loses

= + += 0, ,= 0, , , ,= 0, , , ,

Testing• RiverFlow2D vs Experimental data• and HEC-RAS

207 experiments

• RiverFlow2D

• HEC-RAS

Testing

• Free-surface flow

Q(m3/h) DATA RiverFlow2D RiverFlow2D HEC-RAS HEC-RASBridge Depth Depth Error Depth ErrorRect 1 9.20 5.70 5.20 8.77 6.06 6.32Rect 2 9.20 4.20 4.36 3.81 4.78 13.81Rect 2 14.80 6.00 5.91 1.50 6.52 8.67T 5.80 3.20 3.27 2.19 3.49 9.06T 8.20 4.00 3.98 0.50 4.29 7.25Arch 5.80 5.00 5.03 0.60 5.82 16.40

Testing

• Bridges under pressure flow

Q(m3/h) DATA RiverFlow2D RiverFlow2D HEC-RAS HEC-RASBridge Depth Depth Error Depth ErrorRect1 12.8 7.5 6.54 12.80 8.39 11.87T 15.9 6.5 6.09 6.31 6.87 5.69Rect3 5.9 4.3 4.47 3.95 5.29 23.02Arch 8.26 5 5.65 13.00 8.38 67.60

RiverFlow2D GATES Component

RiverFlow2D GATES ComponentCapabilities

DATA• Crest elevation Zc• Hgate• Ha time series

• Arbitrary plan alignment• Free surface flow• Overtopping

Hydrologic Component

• Distributed model• Rainfall/Evaporation

– Spatially distributed, varied in time

• Infiltration– Spatially distributed

parameters– Infiltration losses

Distributed Hydrologic Modeling• Highly dependent on mesh structure

• Square element grids are the most numerically viscous and show flow directionality

• Triangular-cell flexible meshes outperform gridded models.

Hydrologic Component• Rainfall/Evaporation

– Uniform in space, varied in time

– Spatially distributed, varied in time

– Allows for virtually any rainfall input: Radar, gauges, etc.

Hydrologic Component• Infiltration

– Spatially distributed parameters

– Infiltration rates• Horton• Green-Ampt• SCS-CN

Required Data• Rainfall/Evaporation

– Precipitation time series for each gauge– Polygons of influence of each gauge

• Infiltration– Polygon data set for infiltration parameters– Infiltration method calculation data for each polygon

• Horton: k, fc, fo• Green-Ampt: K, , • SCS: CN,

On-going developments: SAC-SMA• SAC-SMA (Sacramento Soil

Moisture Accounting Model)• Conceptually based rainfall

runoff model with spatially lumped parameters

• Widely used by NOAA-NWS river forecast centers in the US

• Developed to generate river forecasts on watersheds with a response time > 12 hours

Burnash, R. J. C., (1995). The NWS River Forecast System - catchment modeling. In: Singh, V. P. (Ed.). Computer Models of Watershed Hydrology, 311-366. Burnash, R.J.C., R.L. Ferral, and R.A. McGuire, (1973),’ A Generalized Streamflow Simulation System - Conceptual Modeling for Digital Computers’, U.S. Department of Commerce, National Weather Service and State of California, Dept. of Water Resources, March.

High Resolution 2D Hydraulics

Detailed hydrodynamics around Structures

Green River,USA.

Urban Flooding from Rainfall Events. Haiti.

RiverFlow2D Modules

• MD: Mud and Debris Flows• ST: Sediment Transport• PL: Pollutant Transport • OilFlow2D

MD: Mud and Debris Flow

• Non-Newtonian Fluids• Hyperconcentrated flows• 8 Rheological Formulations• Granular flow• Mud/debris floods• Tailings dams

Rudd Creek, Utah, USA.

Dam-Break Flooding, Mexico.

ST: Sediment Transport

• Bed load• Suspended load• Multiple size fractions• Erosion / deposition

High-resolution Erosion and Deposition

PL: Pollutant Transport

• Advection-Dispersion-Reaction• Multiple – simultaneous pollutants• Inter-pollutant first order reactions

Nitrogen ConcentrationsTrou-du-Nord River, Haiti

OilFlow2D

• Overland oil spills• Any viscous fluid• Viscosity-density f(Temperature)• Temperature f(time)

Overland Oil Spills. Pipeline Bursts, California, USA,

RiverFlow2D Verification & Validation

RiverFlow2DVerification and Validation

Questions?

rey@hydronia.com www.hydronia.com