30 oktober 2015

Application of Urban Water BalanceModel for Utrecht Station Area

Reinder Brolsma and Roy Molenaar

Why a simple urban water balance model

• Application in data poor locations of phases of projects

• Understanding the urban water system including water supply and demand

• Quantify chronic (water) stress and drought

• Scenario analyses• Quantify effects of climate and land use scenarios• Quantify effect of adaptation measures

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Utrecht example

• What can be achieved by different sustainable land use options

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Urban water balance model

• 0D- Bucketmodel

• RTC-Tools (http://oss.deltares.nl/web/RTC-tools)

• Implicit scheme

• Definition of states and fluxes in C++, parameterization in XML

• Calibration using (OpenDA)

30 oktober 2015

Urban Water Balance Model – Full version

30 oktober 2015

Urban Water Balance Model – Utrecht version

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Paved Paved permeable

Runoff Infiltration

Evaporation

Through fall

Vegetation

Evapotranspiration

8

Configuration

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<storageNode id="PAV"><AREA>1.3</AREA><input>

<unitVolume>P</unitVolume></input><state>PAV</state>

</storageNode>

<link><evaporationInterception id=“PAV_evaporation"><parameter>

<AREA1.3</AREA></parameter><input>

<HUp>PAV</HUp><EP>EP</EP>

</input><output>

<Q>e_pav_Q</Q></output></evaporationInterception>

</link>

<link><percolation id="infiltration PAV">

<parameter><AREA>1.3</AREA><PERC>0.005</PERC>

</parameter><input>

<HUp>PAV</HUp><HDown>UZ</HDown>

</input><output>

<Q>perc_pav_Q</Q></output>

</percolation></link>

Paved permeable

Infiltration

Evaporation

<storageNode id="UZ"><AREA>3.6</AREA><state>UZ</state>

</storageNode>

Calibration

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Introduction Background Method Results Discussion Conclusion

0

0,05

0,1

0,15

0,2

0,25

0,3

0,35

0,4

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Gro

undw

ater

leve

l(m

+NAP

)

Observed

Simulated

-Observed groundwater levels for the year 2010-Nash-Sutcliffe of 0.61-More uncertainty during and after rainfall events-Better estimations during dry periods.

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Water fluxes summer

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Water fluxes winter

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Land use scenarios

• Replace closed paved by permeable pavement• Replace closed and permeable paved by highly permeable

pavement• Connect roof discharge from sewer system to groundwater• Increase paved surface by replacing green area• Increase unpaved area by replacing paved area (10%)• Increase unpaved area by replacing paved area (25%)• Increase surface water

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Water fluxes permeable pavement

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Introduction Background Method Results Discussion Conclusion

Effects on groundwater

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0,2

0,24

0,28

0,32

0,36

0,4

0,44

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Gro

undw

ater

leve

l(m

+NAP

)

Current

permeable pavement case 1

permeable pavement case 2

disconnection roofs

increased paved surface

more green 10%

more green 25 %

more surface water

• Permeable pavement and disconnection of roofs improvesgroundwater levels

• An increased paved surface reduces groundwater levels

Effects on evapotranspiration

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-6

-4

-2

0

2

4

6

8

10

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Evap

otra

nspi

ratio

nch

ange

(mm

)

disconnection roofs

permeable pavement case 2

permeable pavement case 1

more green 10%

more green 25 %

green roofs extensive

green roofs intensive

blue roofs water retention

more surface water 4x

increaed paved surface

more surface water 2x

• Vegetation and green roofs improve evapotranspiration (cooling)

30 oktober 2015

Urban Water Balance Model

• Urban water system and water cycle• Model runs fast• Fast setup from global and local datasources• Effect of scenarios (e.g. climate, landuse, …)• Effect of measures