UK EA benchmark 2 (Water Module) and Pump (Water Overlay): Difference between pages

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[[Image:result_case2_ukbm.gif|left|Animation of the test result for case 2, generated by the {{software}}. Map dimensions = 2,000 x 2,000 m. Grid-cell size = 5 m.]]
Pumps are constructions which can move water against its natural flow. Specifically, a pump with a positive pump speed will pump water from the entry point with a lower [[water level (Water Overlay)|water level]] to the entry point with a higher [[water level (Water Overlay)|water level]]. If no (differing) water levels are defined, the [[terrain height (Water Overlay)|surface height]] is used instead.
This page reports on the performance of the {{software}}'s [[Water Module]] by means of the UK EA benchmark '''Test 2 – Filling of Floodplain Depressions'''.__NOTOC__


The test has been designed to evaluate the capability of a package to determine inundation extent and final flood depth, in a case involving low momentum flow over a complex topography.<ref name="Néelz"/>
The pump's direction does not change during the simulation.


A copy of this test project is made available to everyone, providing hands-on insights to those interested. The project can be found on the LTS server under the name '''UKEA benchmark 2'''.  
[[File:waterwizard_icon_pump_q.png]] A pump is a [[Line-based_construction_(Water_Overlay)|line-based construction]].
{{Overlay attribute
|attribute=[[Pump_q_(Water_Overlay)|PUMP_Q]]
|unit=m3/s
|description=The speed at which water is pumped from the lower end-point to the higher end-point.
|defaultvalue=n/a
|icon=[[File:waterwizard_icon_pump_q.png]]
|attribute2=[[Lower_threshold_(Water_Overlay)|LOWER_THRESHOLD]]
|unit2=m
|description2=The threshold of the lower entry of the Pump. Water flows from the lower entry to the higher entry until the water level at the lower entry has reached the threshold. If not selected, the Lower Threshold will be ignored as a mechanic.
|defaultvalue2={{novalue}}
|icon2=[[File:waterwizard_icon_lower_threshold.png]]
|attribute3=[[Upper_threshold_(Water_Overlay)|UPPER_THRESHOLD]]
|unit3=m
|description3=The threshold of the higher entry of the Pump. Water flows from the lower entry to the higher entry until the water level at the higher entry has reached the threshold. If not selected, the Upper Threshold will be ignored as a mechanic.
|defaultvalue3={{novalue}}
|icon3=[[File:waterwizard_icon_upper_threshold.png]]
|attribute4=[[Inlet_capacity_(Water_Overlay)|INLET_CAPACITY]]
|unit4=m3/s
|description4=The maximum possible m3 water that can flow through this Pump.
|defaultvalue4=n/a
|icon4=[[File:waterwizard_icon_inlet_capacity.png]]
}}
==Notes==
* A negative value for the PUMP_Q attribute is also allowed, in which case water can be pumped in the reverse direction. Sometimes referred to as ''draining''.


<br style="clear:both">
==See also==
==Description==
* [[Pump formula (Water Overlay)|Pump Formula]]
[[File:dem_case2_ukbm.png|left|thumb|400px|Fig. (a): Map of the DEM showing the location of the upstream boundary condition (red line), ground elevation contour lines every 0.05 m and output point locations (crosses).]]


The area modelled, shown in Fig. (a), is a perfect 2,000 m x 2,000 m square and consists of a 4 x 4 matrix of ~0.5-m deep depressions with smooth topographic transitions. The DEM (digital elevation model) was obtained by multiplying sinusoids in the north to south and west to east directions, and the resulting depressions are all identical in shape. An underlying average slope of 1:1,500 exists in the north to south direction, and of 1:3,000 in the west to east direction, with a ~2-m drop in elevation along the north-west to south-east diagonal.<ref name="Néelz"/>
{{WaterOverlay hydraulic structure nav}}
 
The inflow boundary condition was applied along a 100-m line running south from the northwestern corner of the modelled domain, indicated by a red line in Fig. (a). A flooding with a peak flow of 20 m<sup>3</sup>/s and time base of ~85 minutes was implemented according the hydrograph in Fig. (b). The model was run for 2 days (48 hours) to allow the inundation to settle to its final state.<ref name="Néelz"/>
 
[[File:flood_hydrograph_case2_ukbm.png|left|thumb|x200px|Fig. (b): Inflow hydrograph, which functioned as upstream boundary condition]]
<br style="clear:both">
 
==Initial and boundary conditions==
* Initial condition: dry bed
* Inflow along the red line in Fig. (a)
* All other boundaries are closed
 
==Parameter values==
* Manning’s ''n'': 0.03 (uniform)
* Model grid resolution (m): 20 m (or ~10,000 nodes in the area modelled)
* Simulated time (h): 48
 
==Technical setup==
The required DEM is provided as an ASCII file (test2DEM.asc). As its cell size is 2 m, whereas the test is expected to be run on a 20-m grid, it will be automatically rescaled by the [[Grid Rasterizer|grid rasterizer]]. The dimensions of the test area must be 2,000 by 2,000 m. The original DEM had an offset of -200 m, which was cropped down to -20 m (= 1 grid cell) so it could function as border cell. The rescaled and cropped ASCII file will shortly be provided as part of a .zip found at the bottom of this page.
<ul>
<li style="display:inline-block">[[File:hmapori_case2_ukbm.png|thumb|x353px|Original 2-m heightmap (2,400 m x 2,400 m)]]</li>
<li style="display:inline-block">[[File:hmapcrop_case2_ukbm.png|thumb|x300px|Cropped and rescaled to 20-m grid (2,040 m x 2,040 m). The black perimeter designates the border cells.]]</li>
<li style="display:inline-block">[[File:inlets_case2_ukbm.png|thumb|x300px|Inlet series in the upper left corner.]]</li>
</ul>
 
In order to regulate the water level according to the water-level graph, the following setup was used:
Inlet objects were placed on single grid cells with a constant value for ''x'' = 1 and ''y'' varying from 1 to 5, yielding a total of 5 points. The inlets were configured as follows:
* External area (m<sup>2</sup>):  1,000,000,000 (default)
* Water level (m): 1 (default)
* Threshold (m): none (default)
* Inlet Q (m<sup>3</sup>/s) : 20 in total, thus 4 per inlet
[[File:inlet_q_case2_ukbm.png|thumb|x300px|left|Hydrograph for each individual inlet.]]
<br style="clear:both">
 
==Output as required==
===Stats===
* Software package used: {{software}}
* Numerical scheme: [[Surface flow formula (Water Overlay)|FV (Kurganov, Bollerman, Horvath)]]
* Object flow (m<sup>3</sup>/s): 96,985.64
* Remaining volume water (m<sup>3</sup>/s): 96,982.30
 
===Test results===
Point graph measurements from the {{software}} (left) and other packages (right):
<ul>
<li style = "display:inline-block">[[File:graph_p1_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:graph_others_p1_case2_ukbm.png|x400px|border]]</li></ul>
<ul>
<li style = "display:inline-block">[[File:graph_p2_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:graph_others_p2_case2_ukbm.png|x400px|border]]</li>
</ul>
<ul>
<li style = "display:inline-block">[[File:graph_p3_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:graph_others_p3_case2_ukbm.png|x400px|border]]</li>
</ul>
<ul>
<li style = "display:inline-block">[[File:graph_p4_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:graph_others_p4_case2_ukbm.png|x400px|border]]</li>
</ul>
<ul>
<li style = "display:inline-block">[[File:graph_p5_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:graph_others_p5_case2_ukbm.png|x400px|border]]</li>
</ul>
<ul>
<li style = "display:inline-block">[[File:graph_p6_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:graph_others_p6_case2_ukbm.png|x400px|border]]</li>
</ul>
<ul>
<li style = "display:inline-block">[[File:graph_p7_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:graph_others_p7_case2_ukbm.png|x400px|border]]</li>
</ul>
<ul>
<li style = "display:inline-block">[[File:graph_p8_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:graph_others_p8_case2_ukbm.png|x400px|border]]</li>
</ul>
<ul>
<li style = "display:inline-block">[[File:graph_p9_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:graph_others_p9_case2_ukbm.png|x400px|border]]</li>
</ul>
<ul>
<li style = "display:inline-block">[[File:graph_p10_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:graph_others_p10_case2_ukbm.png|x400px|border]]</li>
</ul>
<ul>
<li style = "display:inline-block">[[File:graph_p11_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:graph_others_p11_case2_ukbm.png|x400px|border]]</li>
</ul>
<ul>
<li style = "display:inline-block">[[File:graph_p12_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:graph_others_p12_case2_ukbm.png|x400px|border]]</li>
</ul>
<ul>
<li style = "display:inline-block">[[File:graph_p13_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:graph_others_p13_p16_case2_ukbm.png|x400px|border]]</li>
</ul>
<ul>
<li style = "display:inline-block">[[File:graph_p14_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:graph_others_p13_p16_case2_ukbm.png|x400px|border]]</li>
</ul>
<ul>
<li style = "display:inline-block">[[File:graph_p15_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:graph_others_p13_p16_case2_ukbm.png|x400px|border]]</li>
</ul>
<ul>
<li style = "display:inline-block">[[File:graph_p16_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:graph_others_p13_p16_case2_ukbm.png|x400px|border]]</li>
</ul>
 
===Last frame===
<ul>
<li style = "display:inline-block">[[File:last_frame_case2_ukbm.png|x400px|border]]</li>
<li style = "display:inline-block">[[File:last_frame_others_case2_ukbm.png|x400px|border]]</li>
: Final timeframe of water levels as generated by the {{software}} (left) and by the other packages (right).
</ul>
 
===Notes===
* Tests were run with a multi-GPU setup. For small cases like this, using single GPU actually leads to faster results. Furthermore, requesting a high number of 576 timeframes further bogs it down. In comparison: 1 GPU with 1 resulting timeframe runs in: 8 s, which is +- 53% faster compared to 2 GPUs with 576 timeframes.
 
==Public test project==
A copy of this test project is made available to everyone, providing hands-on insights to those interested. The project can be found on the LTS server under the name '''UK Benchmark 2'''. In this project the discussed benchmark test is reproduced, based on the cropped version of the initial map (i.e., 2,040 m x 2,040 m). These special map dimensions are generally not selectable in the [[Wizard]] and require configuration through the [[API]].
 
: The locations of the measurement points are:
{|class="wikitable" style="display: inline-table;"
!Point ID
!X
!Y
|-
|1
|275
| -1,780
|-
|2
|275
| -1,290
|-
|3
|275
| -790
|-
|4
|275
| -290
|-
|5
|775
| -1,780
|-
|6
|775
| -1,290
|-
|7
|775
| -790
|-
|8
|775
| -290
|}
 
{|class="wikitable" style="display: inline-table;"
!Point ID
!X
!Y
|-
| 9
| 1,275
| -1,780
|-
| 10
| 1,275
| -1,290
|-
| 11
| 1,255
| -790
|-
| 12
| 1,275
| -290
|-
| 13
| 1,775
| -1,780
|-
| 14
| 1,775
| -1,290
|-
| 15
| 1,775
| -790
|-
| 16
| 1,775
| -290
|}
Note that the coordinate system in this project differs from the one used during the actual benchmark testing as shown in Fig. (b). For the above listed points the center (0,0) is located at the top-left corner instead of the bottom-left, hence will the bottom-right corner have coordinates (2,000;-2,000).
 
===Water level relative to datum===
The time series of a fixed measurement point can be obtained as follows:
 
{{Editor steps|title=obtain water levels relative to datum|Go to the flooding overlay "Water Level (m)".|Select the measuring tool.|From the ''Saved'' dropdown choose your point of interest.|From the ''Base'' dropdown select "Surface Elevation (m)".|Make sure the ''Sum'' box is checked.|Select ''Fit Graph'' to zoom in on the relevant part of the plot.}}
 
===Settings & output===
{|class="wikitable" style="display: inline-table;"
!Setting
!Unit
!Value
|-
|GRAVITY
|m/s<sup>2</sup>
|9.80665
|-
|QUAD_CELL
|''Boolean''
|0
|-
|Open land
|m<sup>2</sup>
|14,786,560
|-
|Manning's ''n''
|s/(m<sup>1/3</sup>)
|0.03
|-
|Calc. pref.
|
|Accuracy
|}
 
{|class="wikitable" style="display: inline-table;"
!Output
!Unit
!Value
|-
|Total volume
|m<sup>3</sup>
|97,194
|-
|Single cells
|
|10,404
|-
|Calc. steps
|
|250,709
|-
|Calc. time
|s
|25
|}
 
Note that these output values may deviate slightly from those of the initial testing phase (i.e. not the public test project), since there is a substantial time gap between when the two projects were set up, during which several changes have been made to the engine.
 
==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-hydraulic-flood-modelling-packages </ref>
</references>
 
[[Category:Benchmarks]]
{{Water Module buttons}}
{{Water Module buttons}}

Revision as of 11:26, 19 June 2019

Pumps are constructions which can move water against its natural flow. Specifically, a pump with a positive pump speed will pump water from the entry point with a lower water level to the entry point with a higher water level. If no (differing) water levels are defined, the surface height is used instead.

The pump's direction does not change during the simulation.

Waterwizard icon pump q.png A pump is a line-based construction. Template:Overlay attribute

Notes

  • A negative value for the PUMP_Q attribute is also allowed, in which case water can be pumped in the reverse direction. Sometimes referred to as draining.

See also

Water Module
Benchmarks button.png
Introduction button.png
Water Module
Benchmarks button.png
Getting started button.png
Tutorials
Benchmarks button.png
Overview button.png
Overview
Benchmarks button.png
Theory button.png
Theory
Benchmarks button.png
Benchmarks button.png
Benchmarks
Group
Inlet
Inlet q • Inlet area • Inlet capacity •  Lower threshold •  Upper threshold • Inlet underground
Pump
Pump q •  Lower threshold •  Upper threshold • Pump angle • Pump capacity • Pump area
Culvert
Culvert diameter • Culvert rectangular height • Culvert threshold • Culvert n
Weir
Weir height • Weir width • Weir angle • Weir coefficient • Weir target level
Sewer overflow
Sewer overflow • Sewer overflow speed
Drainage
Drainage q • Drainage datum • Drainage active • Drainage overflow threshold
Output
Object flow output • Object height output • Object datum output a • Object datum output b • Object width output
Related
Building attributes • Hydrological features •  Terrain attributes • Model attributes • Results • Simulation data


Benchmarks button.png
Introduction button.png
Water Module
Benchmarks button.png
Getting started button.png
Tutorials
Benchmarks button.png
Overview button.png
Overview
Benchmarks button.png
Theory button.png
Theory
Benchmarks button.png
Benchmarks button.png
Benchmarks
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