challenge in urban flood mitigating system: decision support based on cyber-physical-human...

7/25/2019 Challenge in Urban Flood Mitigating System: Decision Support based on Cyber-Physical-Human Infrastructure

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Challenge in Urban Flood Mitigating

System: Decision Support based on Cyber-

Physical-Human Infrastructure

Dadet Pramadihanto!" #ahyu $ Sesulihatien"%!" Soffi Patrisia!" Shiori Sasa&i%!"

'asushi (iyo&i%!

1)Electronics Engineering Polytechnic Institute of Surabaya, Indonesia2)Keio University, Shonan Fujisaa !a"#us, $a#an

Abstract.Currently" floods are not only occurred in the outs&irts of the ri)er

course" but also in the urban area" especially in the big city* $he main problem of

urban flood is the fact that it occurs in highly populated areas* It is a globalphenomenon that causes +idespread de)astation" economic damages and loss of

human li)es* ,ll the strategies basically are good for long term mitigation but not

appropriate for sol)ing the real problems +hen a disaster happens" because it is

static and not real time*$o o)ercome" t+o main points should be de)eloped: socio-cultural &no+ledge on floods and flood pre)ention infrastructure de)elopment*

oth are correlated to build the settlement of flood problem* $herefore" it is

essential to build an integrated system combining Cyber-Physical-Human* $heproposed system includes .! physical layer that consist of sensors rainfall and ri)er+ater le)els and satellite sensors" .%! abstract layer consist of flood modelling ./!

interaction +ith human *Mitigation system based Cyber - Physical - Human +ill be

)ery useful for agencies related to flood control and as a decision ma&ing tool for

the go)ernment and society at large* Surabaya is chosen as study area

Keywords. Cyber-Physical-Human" urban flood" flood-spread prediction"

mitigation"sensor


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Introduction

Indonesia is &no+n as one of the )ulnerable countries to flood disaster* Currently"floods are not only occurred in the outs&irts of the ri)er course" but also in the urbanarea" especially in the big city in Indonesia 01* Flooding in urban areas is not only inthe conse2uence of nature-made phenomenon such as hea)y rainfall but also man-made

e)ent associated +ith their acti)ities +ith lac& of drainage 0%1* $he main problem ofurban flooding is the fact that it is occurred in highly-populated areas* It is a globalphenomenon that causes +idespread de)astation" economic damages and loss of humanli)es* 0/1 For this reason" an effecti)e strategy in mitigation plays the important role*

$he strategies in mitigation are different for e)ery country* For e3ample" in HoChi Minh "4ietnam" mitigation is focused on infrastructure planning 051" in

ang&o& "$hailand" adaptation planning in climate change is chosen as solution 06 1" inrisbane ",ustralia" adaptation strategies addressing flood ris& management issues ofan urban area +ith intensi)e residential and commercial uses 071* In Indonesia" thestrategy is emphasi8ed on the infrastructure planning based on the history of floodshappened in past 091* ,ll strategies basically are good for long term mitigation but notappropriate for sol)ing the real problems +hen a disaster happens" because it is static

and not real time*Some research in se)eral countries propose another real-time methodbased on the characteristics of their countries* In ombay" real-time mitigation isimplemented to maintain flo+ at pre-determined le)els 01" and U( applied a system topredict the spatial and temporal distribution of both rainfall and surface flooding 0;1*,ll methods are not comparable" because they are all uni2ue in accordance +ith thecultural and geographic condition*

In Surabaya" flood mitigation in)ol)es not only planning but also communityparticipation 0utput of the system

is real time prediction of flood spreading as an early +arning system* $he main impactis an early response and e)acuation by prediction of flood area* In long-term" it +illbuilt flood history map that can be used for flood pre)ention infrastructure drainagenet+or&s de)elopment planning*

1. An Approach on the CPH for Urban Flood

Cyber - Physical - Human .CPH! is a ne+ research field that integrates cyber

.)irtual +orld!" physical .sensor! and human .interaction! 0%10/1051* $hese systemsare often implemented for public safety aspect" for e3ample emergency disaster 0/1and e)acuation 051* CPH system consists of three main components: the physicalelements to be controlled" cyber elements that represent communication lin&s and


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soft+are" and human social interaction as a representation relating to the physicalelements that are controlled 0%1* Frame+or& of CPH is focused on the issue in +hichis constructed by the scenario 061* CPH frame+or& is prepared from element +ithrefer to the en)ironment? the main elements of the CPH is a sensor system" an abstractlayer" and human scenario*

In this study" +e focus on mitigation system of flooding in urban areas +hichcharacteristics is different +ith ri)er flood mitigation *$+o main aspect of mitigation inthis study are processing data of sensors: en)ironment and satellite" and a predictingflooded areas to pre)ent greater damage* $he prediction data +ill be input for DSSe)acuation and disaster response*

$his system is e3pected to be useful for e)ery different le)el* For e3ample flood-

related agencies can perform decision in real time condition" people +ill get

information about the le)el of flood ha8ards in their respecti)e regions" specificcommunities such as industrial or business can follo+ up the information to rescuetheir assets and @o)ernment can de)elop decision-ma&ing relating to the handling ofthe disaster and post- disaster reco)ery*

2. Systems Design and Case Study of Urban flood in Surabaya City

Urban flood management emphasis on de)eloping a cyber-infrastructure for urbanflood management* Cyber structure +ill be employed for handling the data collectionand integration" the data management" data mining and &no+ledge e3traction*Methodological approach in line +ith the phases of disaster management: that ispreparedness" mitigation" response" and reco)ery* In general" the system is illustrated inFigure *

Figure 1. >)erall System

Figure sho+s o)erall flood management system in Surabaya* System consists ofmonitoring" early +arning" mitigation" e)acuation system and informationdissemination system* In this research +e collaborate +ith (eio Uni)ersity to


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analy8e impact of disaster and pro)ide recommendation policy based on (eioUni)ersity model* In this paper" +e focus on flood spreading model formitigation*

2.1. Abstract Layer !itigation !odeling

Disaster response in urban flood management generally relates to control" flood

mitigation" e)acuation" and disaster relief during floods* Mitigation +ill focus on thespread of a flood +ith the spatiotemporal analysis* System design is illustrated in figure%* #hile the e)acuation and disaster response focused on the e)acuation of residentsand optimi8ation of alternati)e roads during flood period*

Figure 2 shos the syste" for "odelling s#read of flood% &ased on the satellite

i"ages, land elevation, drainage netor', flood histories and ater level(rain sensors

to "odel the flood s#read% n satellite i"ages ith a resolution of *+" by *+" #er

#iel e i"#le"ent 2-di"ensional cellular auto"ata lattice(cell, here each cell has

the infor"ation land elevation, land infiltration, and land classification .land,

drainage(river, road, greenery)% /hese #ara"eters ill be discussed in section 2%2%

/he #rocedure is as follos0

a% ain #our in into the certain areas, as a nature of ater, the ater flooded the cell

ith the loest elevation% If the rainfall eceeds the infiltration ca#acity of the land,

the ater overflos into the net loest cell% /his #rocess ill continuous until it

reaches saturating condition

b% If the cell is #art of a drainage channel or river, the ater ill filling the cell

drainage #athays%

c% Fro" the results of .a) locations s#read flooding can be deter"ined and flood

inundation area can be obtained by counting the nu"ber of cell are flooded%

d% Fro" the results of .a) de#th of inundation flood can be #redicted by calculating

the difference in highest elevation cell and the loer elevation in the area%

e% n the other hand, if the ater filling in drainage channel is over its ca#acity, the

ater ill overflo% /he flo of ater ill be s#reader and #redicted by folloing

#rocedure .a)%

f% hen the rain sto##ed, the #rocedure .a) can be used to calculate flood subsidence%


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Figure 2. Flood spread modeling*

Mitigation scenario proposed in this paper is based on the pattern of the spread*Spread prediction in)ol)es processing the sensor data of rainfall" topographic data fromsatellites" and classification of soil types* $his prediction +ill apply on each lattice ofcellular automata" a techni2ue similar to the @IS-based urban flood inundation model.@UFIM! 071 to calculate the )olume of +ater in each lattice*

R ( t , x , y )=P ( t , x , y ) F( t , x , y )D (t , x , y ) .!

+here".t, , y)is the e3cess rain +ater )olume .in m/!"P.t, , y)is the total )olume ofrainfall"F.t, , y)is the total )olume of rain +ater is absorbed" and 3.t, , y)is the total)olume of the incoming rain+ater drainage .ri)ers" +ater pump" etc*!*

$he relations bet+een the absorption capacity of the soil and time is e3pressed inthe follo+ing Horton e2uation:

F( t , x , y )=fc+(f0+ fc)ekt

.%!

+here" f+ is the infiltration capacity .soil absorption capacity! at any time" f+ is the

initial infiltration capacity at t A


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ele)ation" the +ater +ill remain stagnant*Spread flooding predicted by cellular automata method based on mathematical

models of flo+ in e2uation .%!* Figure / sho+s the %-dimensional lattice .cell! ofcellular automata +ith )on eumann neighborhood 091*

Figure "* Cellular ,utomata arrangement*

eighborhood cells are cells that +or& on the status of a cell in cellular automata*

eighborhood of a cell generally consists of the cells in the )icinity* >ne model is the4on eumann neighborhood" +here the neighboring cells are shaped as a diamond*$his scheme can be used to define a set of cells that surround a particular cell .3

N(x0, y 0)v ={ (x , y ) :|xx0|+yy0 r } ./!

Illustration 4on eumann neighborhood of radius" r A


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Figure #. loc& diagram of Satellite data processing

Input is the ra+ data from the Eandsat 6 $M satellite imagery .$hematic Mapper!*$his procedure is too& on as follo+s:

o Separating ra+ satellite image data based on the +a)elength spectrum

o @ image constructed by combining each pi3el of each band to @

image

o

$he process of calculating D4I" soil classification" and Cloud eductionprocess*

o ,lignment +ith @IS coordinates so that it can be integrated +ith @IS*

Image normali8ation or D4I .ormali8ed Difference 4egetation Inde3! 01 is acalculation to determine the image of the le)el of greenness" in +hich is representinitial 8oning of )egetation* D4I can indicate parameters associated +ith )egetationparameters" among others" biomass green foliage" green foliage area" and is a )alue thatcan be estimated for )egetation classification* In this data satellite" land use D4I

)alue is obtained by the calculation of near infrared" and )isible light reflected by)egetation%D4I )alues are obtained by comparing the data reduction" near infraredand )isible +ith the second summation data* $he follo+ing calculation formula used onEandsat satellite imagery:

NDVI=NIRVisibleNIR+Visible

.5!

#here D4I is numeric processing result of channel 5 and +hile )isible isnumeric-processing result of channel /*ange of D4I )alues is in bet+een -*< to*


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+ater )apor cloud and sno+* Surface )egetation D4I )alue ranges from


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Surabaya is a 6-million-population city" the former capital of the ussian =mpire? itaccumulated a grand cultural and architectural heritage and )ery e3pensi)e usinessesand industries* ,nd all that treasure lies in the lo+land of the e)a i)er delta" +ith thehistorical center lying at the sea le)el or mere -5m abo)e it*>)er /


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.c! Drainage map of Surabaya

.d! Combination of .a!" .b! and .c!

Figure &.Satellite image processing*

$he first procedure is D4I calculation* It is purposed to determine theclassification of an area based on a certain scale* D4I )alues are calculated bye2uation .!* Classification results are sho+n in table *

'able1.esult of D4I and @

Classification Area %ange of (D)I and %*+

,ater D4I A -


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needed* $hen +ater and cloud could be classified as sho+n in figure 7a* $he figuresho+s differences bet+een cloud .+hite!" +ater .blue!" and land .red!*

$he ne3t step is proceeded D=M from satellite data* D=M is digital model or /Drepresentation of a terrainJs surface* In this case" D=M represent height of e)ery pi3elby gray scale from


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.b! ,fter 5 hours

. c ! ,fter 7 hours

Figure /.Simulation result by % hours

$he left side of figure 9 sho+s spreading in combination map" +hile the right sidesho+s spreading area* $he spreading area are mostly starting from around of drainage

system" then spreading to+ard the certain area" in this case Central of Surabaya* $hispattern in also happened in se)eral big city li&e ombay .India!01" Ga&arta .Indonesia!"risbane .,ustralia!071* $his is the specific characteristic of pure urban flood that israre happened in another type of flood such as flash flood" coastal flood or ri)er flood*

In the urban flood" changes in land use are in line +ith change in infiltration of soil*$he land changes from soil to building or road" +here the +ater-absorbing capacity islo+* 0;1* ,dditionally" in the big city contour of do+nto+n tends to flat* It is ma&e asense that the flood leads to spread in do+n to+n* $his result is important for planningreal time e)acuation system during flood session*

,nother interesting result from the simulation is fact that spreading is occurs

nonlinear by time In first % hours" only se)eral small inundation point" but % hours laterit become larger more than t+ice and the in the third % hours almost all area isinundated* It means response of disaster in urban flood should be conduct as early as

possible before flood happened* >ther+ise" cost of the disaster +ill be increasedramatically 0%


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Figure 0.Simulation result by % hours

In figure " most of inundation point in Surabaya starting in area +here secondaryand primary canal meet* $heoretically" +hen +ater from larger surface section enteringthe smaller one" flo+ of +ater +ill increase causing o)erflo+ed in this area 0%1* $hisresult could be implemented in planning of infrastructure in the future*

,s a )alidation" simulation result is compared +ith flood history map of Surabaya"

%


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prospects of CPH for disaster is a dynamic system that is integrated" real time and"based on local &no+ledge" because it is a representation of the interaction bet+eenhuman and natural" +ith people through the +orld* Impact deri)ed from thede)elopment of IC$-based disaster management system is a reliable system" pri)acy"easy to de)elop and support national self-reliance in disaster management* $he strategy

includes impro)ement in technical aspect and collaboration among researcher to share&no+ledge in disaster management*

In critical situations decisions "ust be "ade very fast, therefore the re7uire"ent on all

our si"ulations as a res#onse ithin "inutes, ith a "ai"u" of a fe hours for

long-ter" #redictions% /his restriction deter"ined the "ethods and codes selected for

si"ulation of inundation on a city scale% /he surface flo dyna"ics is si"ulated by the

3yna"ic a#id Flood S#reading 8odel .3FS8), develo#ed by the 9 allingford

tea" and ada#ted in our #roject% /he "odel is based on a co"#utationally efficientdiffusion-ave based inundation a##roach, sufficiently robust for use in flood ris'

"odels :2;


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System" htttp:LLsa*ee*ic*ac*u&LpublicationsLgelenbeNgorbilN+uNICCCN%

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