onno bokhove , tom kent , henk de poot and wout zweersamttk/files/wetropolisposteregu2019.pdfonno...
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Galton boards: steel balls travel down and land in 1 of 4columnswithateachjunc8ona50%chanceofballgoingle=orright. Galton boards randomly determine: (i) rainfall amount(columns: 1s, 2s, 4s, or 9s) and (ii) rainfall loca8on (columns:lake/reservoir, moor & reservoir, moor, or no rainfall).ProbabilityasymmetricGaltonboard:(3,7,5,1)/16.Planview:
Wetropolis:modelsforeduca8on&water-managementoffloodsanddroughtsOnnoBokhove1,TomKent1,HenkdePoot2andWoutZweers3
1SchoolofMathema8cs,UniversityofLeeds,Leeds,UK;2Nobis&3Wowlab,Enschede,TheNetherlands
“Wetropolis:makingtangible,interac8vemodelsforeduca8on&policy”isanEFRORDconsor8um(EUfundforregionaldevelopment),ledbyNobis,DrHenkdePoot,[email protected] References
Educa8on&water-managementMathema8csofextremerainfall/flooddemonstrator
Wetropolis interac8ve flood demonstrator is based on amathema8cal design and visualises how extreme rainfall events cancauseextremeriver-floodeventsinadynamic,conceptualandscaledtable-topset-up.GaltonboardsareusedtomodeldifferentrainfallscenariosoverthecourseofaWetropolisday(wd=10seconds)andextremefloodinginacitybyrainfallonthecurrentandpreviousdays,asintherealworld[1].
Overview,modelleda=erLeeds’BoxingDayflood2015(1:300yrreturn-periodevent):• 1:100 sloped river bed;Wetropolis day 10s; upstream inflow;with
canal,reservoir/lake&porousgroundwatermoordrainingintoriver;• chance of rare flood event in city a=er 90% rainfall (9s/wd) is
(1/16)x(7/16)=7/256witha(256/7)x10s=6:06minreturnperiod.
Wetropolis isdesigned toflood ( r i g h t ) u n d e rextreme rainfall (9s/wd)in moor & reservoir; twoconsecu8ve wd ’ s o fextremerainfall leadtoachance of (7/256)2 <1%;cf.Boxing-Dayflood2015,see; hkps://youtube.com/watch?v=N4Sp5gHXcz4
Droughts:tovisualisedroughtforthe1/16throuteofadryday,weusetheoutcomeofthefirstGaltonboard(notusedwithoutrainfall)a=er2pinswith(3,1)/4probability.Forthe1/4-case,weenforcedroughtfor4days,visualisedbyadrinkwaterpipefromthemoorfallingdry:nowatersupply!Newproba-bili8esthenadjustto:(12,28,20,3,4)/67forrainfallinreservoir,moor&reser-voir,moor,norainonsingleday&norainfor4days.Droughtreturnperiod:67x10s=11:10min.Newfloodingreturnperiod:(16x67/28)x10s=6:23min.
Modulardesign:wearecurrentlymakingaWetropolisNFMdemonstratorwith• par8cipant-built
leakydamsinoasis-landscape;and,
• river-bedinsertsofdifferentroughness(“trees,cement,gravel”).
NFM=NaturalFloodManagement.
PromoteacDvethinkingaboutdifferentscenariosofflood/droughtmi8ga-8on:Wetropolisisusefulprecursorincrea8on[2]ofwater-management
solu8ons;alsoenhancesci8zens’par8cipa8on.
Wetropolisledtoflood-excess-volumebasedcost-
effec8venessanalysis,e.g.,RiverBragueflood
2015,France[3]: