View source for UK EA benchmark 4 (Water Module)

This page reports on the performance of the {{software}}'s [[Water Module]] by means of the UK EA Benchmark '''Test 4 – Speed of flood propagation over an extended floodplain'''.__NOTOC__

The objective of this test is to assess the package’s ability to simulate the celerity of propagation of a flood wave and predict transient velocities and depths at the leading edge of the advancing flood front. It is relevant to fluvial and coastal inundation resulting from breached embankments.<ref name="Néelz"/>

==Description==
This test is designed to simulate the rate of flood wave propagation over a 1,000 x 2,000 m floodplain following a defence failure (Fig. (a)). The floodplain surface is horizontal, at datum (= 0 m). One inflow boundary condition will be used, simulating the failure of an embankment by breaching or overtopping, with a peak flow of 20 m<sup>3</sup>/s and time base of ~6 h. The boundary condition is applied along a 20-m line in the middle of the western side of the floodplain.<ref name="Néelz"/>

[[File:topdown_case4_ukbm.png|thumb|left|Figure (a): Modelled domain and the locations of the 20-m line of inflow, 6 output points, and the aimed for 0.1-m and 0.2-m contour lines at t = 1 h (dashed) and t = 3 h (solid), respectively.]]
[[File:UK_test_4.gif|right|Animation of the test result for case 4, generated by the {{software}}. Map dimensions = 1,000 x 2,000 m. Grid-cell size = 5 m.]]
[[File:hydrograph_case4_ukbm.png|thumb|center|Figure (b): Hydrograph applied as inflow boundary condition.]]
<br style="clear:both">

==Boundary and initial condition==
* Inflow boundary condition as shown in Fig. (b)
* All other boundaries are closed
* Initial condition: dry bed

==Parameter values==
* Manning’s ''n'': 0.05 (uniform)
* Model grid resolution (m): 5 (or ~80,000 nodes in the area modelled)
* Simulated time (h): 5

==Required output==
{| class=wikitable  align=right
!Point ID
!X
!Y
|-
|1
|50
|1,000
|-
|2
|100
|1,000
|-
|3
|200
|1,000
|-
|4
|300
|1,000
|-
|5
|300
|1,000
|-
|6
|300
|1,300
|}
* Software package used: version and numerical scheme
* Specification of hardware used to undertake the simulation: processor type and speed, RAM
* Minimum recommended hardware specification for a simulation of this type
* Time increment used, grid resolution (or number of nodes in area modelled) and total simulation time to specified time of end
* Raster grids (or TIN) at the model resolution consisting of:
** Depths and at t = 30 min, 1 h, 2 h, 3 h and 4 h
** Velocities (scalar) at t = 30 min, 1 h, 2 h, 3 h and 4 h
* Plots of velocity and water elevation v. time (suggested output frequency: 20 s) at the 6 locations represented in Fig. (a) and provided as part of dataset

==Dataset content==
* Upstream boundary condition table (inflow v. time). Filename: ''Test4BC.csv''
* Location of output points. Filename: ''Test4Output.csv''

The model geometry is as specified in Section 2. No DEM is provided, as the surface elevation is level at datum (= 0 m).<ref name="Néelz"/>

==Technical setup==
[[File:setup_case4_ukbm.png|thumb|right|x300px|Figure 1. The relative positions of the measurement points used in this test.]]
* Flat surface
* Grid-cell size (m): 5
* Area size (m): 1,010 x 2,010 (required domain of 1,000 x 2,000 + 5-m border)
* The measurement points were positioned correctly (see Fig. 1) 
In order to regulate the boundary discharge according the hydrograph (Fig. 2), 2 inlets were implemented. Both inlets occupied one grid cell, one of these located above and the other below the green center line (Fig. 3). The inlets were configured as follows:
* External area (m<sup>2</sup>): 1,000,000,000
* Water level (m): 1
* Threshold (m): none
* Inlet Q (m):
[[File:inletq_case4_ukbm.png|thumb|left|x300px|Figure 2. Hydrograph displaying the implemented individual and combined inlet fluxes.]]<br style="clear:both">
[[File:inletpositions_case4_ukbm.png|thumb|left|x300px|Figure 3. Positions of the inlet cells (red squares) with respect to the center line of measurement (green).]]<br style="clear:both">

==Results==
===Stats===
* Software package used: {{software}}
* Numerical scheme: FV (Kurganov, Bollerman, Horvath)*
* Specification of hardware used to undertake the simulation: 
** Processor: Intel Xeon @2.10GHz x 8
** RAM (GB): 62.8
** GPU: 2x NVidia 1,080
** Operating system: Linux 4.13
* Time increment used: adaptive
* Grid resolution (m): 5
* Simulation time (s): 29 for 900 timeframes
* Object flow (m<sup>3</sup>/s): 283,723.8
* Remaining water volume (m<sup>3</sup>/s): 283,606.9

===Raster grids (or TIN) at the model resolution for water level and flow velocity===
====Contours====
<ul>
<li style="display:inline-block">[[File:contour_30m_case4_ukbm.png|thumb|left|x300px|Contour 30 minutes.]]</li>
<li style="display:inline-block">[[File:contour_1h_case4_ukbm.png|thumb|left|x300px|Contour 1 hour.]]</li>
<li style="display:inline-block">[[File:contour_2h_case4_ukbm.png|thumb|left|x300px|Contour 2 hours.]]</li>
<li style="display:inline-block">[[File:contour_3h_case4_ukbm.png|thumb|left|x300px|Contour 3 hours.]]</li>
<li style="display:inline-block">[[File:contour_4h_case4_ukbm.png|thumb|left|x300px|Contour 4 hours.]]</li><br>
<li style="display:inline-block">[[File:contour_others_case4_ukbm.png|thumb|left|x300px|Contour 1 and 3 hours of others.]]</li>
</ul>

====Cross sections====
<ul>
<li style="display:inline-block">[[File:crosssection_waterlevel_1h_case4_ukbm.png|thumb|left|x300px|Waterlevel cross-section after 1 hour.]]</li>
<li style="display:inline-block">[[File:crosssection_waterlevel_others_1h_case4_ukbm.png|thumb|left|x300px|Waterlevel cross-section others after 1 hour.]]</li><br>
<li style="display:inline-block">[[File:crosssection_velocity_1h_case4_ukbm.png|thumb|left|x300px|Velocity cross-section after 1 hour.]]</li>
<li style="display:inline-block">[[File:crosssection_velocity_others_1h_case4_ukbm.png|thumb|left|x300px|Velocity cross-section others after 1 hour.]]</li>
</ul>

===Plots of velocity and water elevation versus time===
<ul>
<li style="display:inline-block">[[File:waterlevel_p1_case4_ukbm.png|thumb|left|x300px|Waterlevel point 1.]]</li>
<li style="display:inline-block">[[File:waterlevel_others_p1_case4_ukbm.png|thumb|left|x300px|Waterlevel point 1 others.]]</li><br>
<li style="display:inline-block">[[File:velocity_p1_case4_ukbm.png|thumb|left|x300px|Velocity point 1.]]</li>
<li style="display:inline-block">[[File:velocity_others_p1_case4_ukbm.png|thumb|left|x300px|Velocity point 1 others.]]</li><br>
<li style="display:inline-block">[[File:waterlevel_p2_case4_ukbm.png|thumb|left|x300px|Waterlevel point 2.]]</li><br>
<li style="display:inline-block">[[File:velocity_p2_case4_ukbm.png|thumb|left|x300px|Velocity point 2.]]</li><br>
<li style="display:inline-block">[[File:waterlevel_p3_case4_ukbm.png|thumb|left|x300px|Waterlevel point 3.]]</li>
<li style="display:inline-block">[[File:waterlevel_others_p3_case4_ukbm.png|thumb|left|x300px|Waterlevel point 3 others.]]</li><br>
<li style="display:inline-block">[[File:velocity_p3_case4_ukbm.png|thumb|left|x300px|Velocity point 3.]]</li>
<li style="display:inline-block">[[File:velocity_others_p3_case4_ukbm.png|thumb|left|x300px|Velocity point 3 others.]]</li><br>
<li style="display:inline-block">[[File:waterlevel_p4_case4_ukbm.png|thumb|left|x300px|Waterlevel point 4.]]</li><br>
<li style="display:inline-block">[[File:velocity_p4_case4_ukbm.png|thumb|left|x300px|Velocity point 4.]]</li><br>
<li style="display:inline-block">[[File:waterlevel_p5_case4_ukbm.png|thumb|left|x300px|Waterlevel point 5.]]</li>
<li style="display:inline-block">[[File:waterlevel_others_p5_case4_ukbm.png|thumb|left|x300px|Waterlevel point 5 others.]]</li><br>
<li style="display:inline-block">[[File:velocity_p5_case4_ukbm.png|thumb|left|x300px|Velocity point 5.]]</li>
<li style="display:inline-block">[[File:velocity_others_p5_case4_ukbm.png|thumb|left|x300px|Velocity point 5 others.]]</li><br>
<li style="display:inline-block">[[File:waterlevel_p6_case4_ukbm.png|thumb|left|x300px|Waterlevel point 6.]]</li>
<li style="display:inline-block">[[File:waterlevel_others_p6_case4_ukbm.png|thumb|left|x300px|Waterlevel point 6 others.]]</li><br>
<li style="display:inline-block">[[File:velocity_p6_case4_ukbm.png|thumb|left|x300px|Velocity point 6.]]</li>
<li style="display:inline-block">[[File:velocity_others_p6_case4_ukbm.png|thumb|left|x300px|Velocity point 6 others.]]</li>
</ul>

==Notes==
* The steps seen in the velocity profile can be related to the definition of the inlet inflow, which is also in steps.

==References==
<references>
<ref name="Néelz">Néelz, S., & Pender, G. (2013). Benchmarking the latest generation of 2D hydraulic modelling packages. Report: SC120002. Environment Agency, Horison House, Deanery Road, Bristol, BS1 9AH. ISBN: 978-1-84911-306-9. Retrieved from: https://www.gov.uk/government/publications/benchmarking-the-latest-generation-of-2d-hydraulicflood-modelling-packages </ref>
</references>

[[Category:Benchmarks]]