Flood Damage Assessment in Taipei City

7/26/2019 Flood Damage Assessment in Taipei City

1/12

See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/257164403

Flood Damage Assessment in Taipei CityTaiwan

CONFERENCE PAPER JANUARY 2012

READS

110

7 AUTHORS, INCLUDING:

Ming-Hsi Hsu

National Taiwan University

88PUBLICATIONS 1,046CITATIONS

SEE PROFILE

Albert S. Chen

University of Exeter

84PUBLICATIONS 529CITATIONS

SEE PROFILE

Michael John Hammond



SEE PROFILE

Slobodan Djordjevi



SEE PROFILE

Available from: Albert S. Chen

Retrieved on: 08 March 2016
https://www.researchgate.net/institution/National_Taiwan_University?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_6https://www.researchgate.net/institution/National_Taiwan_University?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_6https://www.researchgate.net/institution/National_Taiwan_University?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_6https://www.researchgate.net/institution/National_Taiwan_University?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_6https://www.researchgate.net/institution/National_Taiwan_University?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_6https://www.researchgate.net/institution/National_Taiwan_University?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_6https://www.researchgate.net/institution/National_Taiwan_University?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_6https://www.researchgate.net/institution/University_of_Exeter?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_6https://www.researchgate.net/institution/University_of_Exeter?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_6https://www.researchgate.net/institution/University_of_Exeter?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_6https://www.researchgate.net/institution/University_of_Exeter?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_6https://www.researchgate.net/institution/University_of_Exeter?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_6https://www.researchgate.net/?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_1https://www.researchgate.net/profile/Slobodan_Djordjevic?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_7https://www.researchgate.net/institution/University_of_Exeter?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_6https://www.researchgate.net/profile/Slobodan_Djordjevic?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_5https://www.researchgate.net/profile/Slobodan_Djordjevic?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_4https://www.researchgate.net/profile/Michael_Hammond4?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_7https://www.researchgate.net/institution/University_of_Exeter?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_6https://www.researchgate.net/profile/Michael_Hammond4?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_5https://www.researchgate.net/profile/Michael_Hammond4?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_4https://www.researchgate.net/profile/Albert_Chen2?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_7https://www.researchgate.net/institution/University_of_Exeter?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_6https://www.researchgate.net/profile/Albert_Chen2?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_5https://www.researchgate.net/profile/Albert_Chen2?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_4https://www.researchgate.net/profile/Ming_Hsi_Hsu?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_7https://www.researchgate.net/institution/National_Taiwan_University?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_6https://www.researchgate.net/profile/Ming_Hsi_Hsu?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_5https://www.researchgate.net/profile/Ming_Hsi_Hsu?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_4https://www.researchgate.net/?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_1https://www.researchgate.net/publication/257164403_Flood_Damage_Assessment_in_Taipei_City_Taiwan?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_3https://www.researchgate.net/publication/257164403_Flood_Damage_Assessment_in_Taipei_City_Taiwan?enrichId=rgreq-24fede08-7dbd-4d36-bae9-b81d8f086163&enrichSource=Y292ZXJQYWdlOzI1NzE2NDQwMztBUzoxMDQ1NzQyODMxNTc1MThAMTQwMTk0Mzg2MDcwMQ%3D%3D&el=1_x_2


2/12

Flood Damage Assessment in Taipei City, Taiwan

Ming-Hsi Hsu1

, Meng-Yuan Tsai2

, Yi-Chieh Lin3

, Albert S. Chen4

, Michael J. Hammn!"

,Slb!an #$r!$e%i&'( #a%i! )utler*

1National Taiwan University, Taiwan, [email protected]

2 National Taiwan University, Taiwan, my my [email protected]

3 National Taiwan University, Taiwan,[email protected]

4 University of !eter, U", a.s.chen@e!eter.ac.u#

$ University of !eter, U", m.j.hammond@e!eter.ac.u#

%University of !eter, U", s.djordjevic@e!eter.ac.u#

&University of !eter, U", d.butler@e!eter.ac.u#

ABSTRACT

'n this study, we reviewed the literature on flood dama(e assessment and collected information for

related research in Taiwan to analy)e the relationshi*s between direct flood dama(e, flood fre+uency,

flood de*th, and landuse. The *rocedure for flood dama(e assessment was then develo*ed that

includes the followin( ste*s- a/ 0cenario simulation of inundation *otential. b/ stablishment of the

relationshi* between inundation de*th and dama(e loss for varied landuse. c/ is# analysis of

inundation dama(e.

Tai*ei ity in north Taiwan was ado*tedas the case study to demonstrate the *ro*osed al(orithm.

lood events with return *eriods of $, 1, 2$, $, 1 and 2 years were used for flood ha)ard

analysis to cover *ossible floodin( scenarios. The inundation ha)ard ma*s were first (enerated via

hydraulic modellin(. The re(ional flood dama(e was then estimated usin( a relationshi* between

inundation de*th and dama(e. The flood dama(e e!ceedance *robability 5/ curve for Tai*ei ity

was constructed followin( the association of the loss with its *robability of occurrence. The flood

dama(e 5 curve was further used to inte(rate the dama(e assessments for individual flood events for

a full *robability ran(e *resentation of the flood ris#. The e!*ected annual dama(e was calculated by

inte(ratin( the area under the 5 curve.

KEYWORDS


3/12

'nundation *otential, avera(e annual flood loss, e!ceedance *robability curve

1 ITROD!CTIO

Natural ha)ards, such as earth+ua#e, ty*hoon, flood and debris flow, cause an enormous loss of

*ro*erties and human lives around the world every year. 6arious measures includin( landuse

*lannin( and mana(ement, construction of structural measures, and flood monitorin( and warnin(

systems, can be a**lied to miti(ate the im*act of floodin(. 0ufficient understandin( of the ha)ard ris#

can hel* decision ma#ers to ado*t ade+uate measures for flood dama(e reduction 7ames and 8all,

19:%/. The effectiveness of these alternatives can be evaluated by considerin( the reduction of ris#

that *roceeds from the im*lementations of these measures. lood ris# can be considered to be related

to the nature of the ha)ard and its *robability of occurrence, the *eo*le and assets that are *otentially

e!*osed to the ha)ard, and their vulnerability "ron, 23/. ;hen a *otentially e!*osed *o*ulation

comes into a contact with a ha)ard, their vulnerability will determine the im*acts of the ha)ard.

lood ha)ard can be assessed by field survey, remote sensin( durin( or after an event 8 8a)ard/ ? 6 6ulnerability/ 1/

lood as a major and fre+uently occurred natural ha)ard, its ris# can also be assessed usin( the above

e+uation. lood ha)ard ma*s are the first thin( to be done in flood ris# assessment. lood ha)ard can

be assessed by field survey, remote sensin( durin( or after an event or by com*uter modellin(. The

conce*t of usin( de*thdama(e curves for flood vulnerability study was firstly *ro*osed by ;hite

194$/.

"ET#ODO$O%Y

0ince human activities and flood de*ths are not homo(enously distributedover the s*ace, the s*atial

variations in social and economic activities, and flood ha)ard have to be ta#en into account in the

assessment of the flood dama(e. The data needed for this a**roach includin( land *arcel ma*s and


4/12

socioeconomic activities on each *arcel. These data are multifarious and difficult to establish and

maintain. 't is more difficult if the country is develo*in( and it suffers natural disasters. To investi(ate

the conse+uence of floodin( via numerical simulations, most models divide the domain into a set of

(rid cells. The socioeconomic activities are considered to be homo(eneous within each cell and are

a((re(ated into a sin(le attribute associated with it. The data needed for this model can be derived

from the a((re(ated census data that is easier to obtain than the individual details. The flood dama(e is

then estimated from the flood de*th and the dama(e attributes for each cell. The re(ional flood

dama(e is calculated as the sum of the loss estimated in cells. This *a*er focuses on the develo*ment

of a (ridbased re(ional flood dama(e assessment model.

1&1 #a'a(d analysis

The develo*ment of flood *otential ma*s re+uires a hydraulic model to simulate floodin( under

various scenarios hen et al., 2%/. or urban areas, the sewer system *lays an im*ortant role in the

rainfallrunoff *rocess such that an overland flow model that ne(lects the inertial term in momentum

e+uations, based on the assum*tion that the acceleration term is small com*ared with the (ravitation

and friction terms, is cou*led with the 0; sewer model for hydraulic modellin( 8su et al.,

22/. The de*thavera(ed shallow water e+uations on the overland surface are written as-

( )[ ] ( )[ ]q

y

vd

x

ud

t

d=

+

+

11

2/

dg

quS

x

hfx +=

3/

dgqvS

xh

fy += 4/

where dis de*th AmB, h is water sta(e AmB, uand vare velocity com*onents in ! and ydirection AmCsB,

res*ectively, t is time AsB, ( is (ravitational acceleration AmCs 2B, qis source or sin# *er unit area AmCsB,

34222 dvuunS fx += and34222 dvuvnS fy += are friction slo*es in ! and y direction,


5/12

res*ectively, nis annin(Ds rou(hness, andAAbC=

is detainin( ratiowhich re*resents a linear

ratio of buildin( area to the total area of interest.

To simulate the flow interactions between the sewer system and the (round surface, the draina(e

throu(h inlets to the sewer systems and the overflow from the surchar(ed manholes to the (round

surface are used as model lin#a(es between the overland flow and the sewer models. The former are

treated as sin#s and the latter as sources in the twodimensional model. +s. 2/ to 4/ are solved by a

finite difference numerical scheme, named the Elternatin( =irection !*licit E=/ method, which

allows an initial condition with )ero water de*th and velocity 8su et al., 2/. E sam*le flood

*otential ma* with a return *eriod of 2 year is shown as in i(ure 1.

i(ure 1. lood *otential ma* of 2 year return *eriod in Tai*ei city


6/12

1&) *+lne(aility analysis

The flood dama(e was estimated usin( the ha)ard ma* with the de*thdama(e curves =utta et al.,

23, 0mith, 1994, ;hite, 19%4/. The curve characteristics may be hi(hly affected by the nature of

human activities, which relate to thety*es of landuse. The activities were classified into residential,

commercial retailer, service/, industrial manufacturin(, wholesaler/ and cultural )one in this study.

The flood dama(e data used to derive the curve were collected from a field survey in the fre+uently

flooded area and the dama(e claim information filed with the internal revenue service for ta!

deduction. The data are recorded in a *erhousehold or *erfirm bases. The curves for these different

activity cate(ories, as shown in i(ure 2, were develo*ed in a *revious study of the authors ;an(,

23/ based on flood dama(e data collected after Ty*hoon Nari that caused a major dama(e in the

Tai*ei etro*olitan in 21.

i(ure 2. =e*thdama(e curves for residential, commercial, industrial and cultural )one

1&- Flood damage assessments

lood dama(e can be calculated cell by cell usin( the flood de*ths and the res*ective loss functions.

The re(ional dama(e caused by a flood event can then be assessed by summin( u* the dama(e of all

the cells within the re(ion. The ris# as shown in +. 1/ is defined as the dama(e multi*lied by the

occurrence *robability. E set of flood *otential ma*s return *eriods of $, 1, 2$, $, 1 and 2

years/ with different occurrence *robability, instead of one for a sin(le event, can be *re*ared for the

re(ion for the full ran(e of #nowled(e of the ris#. The ris# of each flood event can first be calculated

by multi*lyin( the estimated dama(e of that event with its occurrence *robability. The avera(e annual

flood loss EEF/ caused by flood ha)ard was used in this study for re(ional flood ris# assessment8ardison and 7ennin(s, 19&2/. The e!ceedance *robability 5/ curve for flood dama(e of a re(ion

can be constructed by usin( the dama(es of each simulated event and its res*ective 5. The EEF can

be defined as the area under the 5 curve of flood dama(e and can be calculated by +. $/ Ernell,

19:9/.

= dxxfxAAFL /.$/


7/12


8/12

Not for urban

develo*ment

E(ricultural and scenic )ones :4 13,&:%

onservation )one 11,3$1

;ater coverin( )one 1,%31

L 'ncludin( Edministrative )one, cultural and education )one, )one for s*ecific *ur*oses, air*ort, recreation )one and others

esidential

2ommercial

Edministrative, 'nstitutional,

5um* 0tation2ultural, 0chool

'ndustrialTrans*ortation, ailroad, 5ower 5lant,

;aste and 0ewera(e =is*osal, Eir *lant

E(ricultural

8i(hway

5ar#, Hreen


9/12

i(ure 3. Fand )onin(s in Tai*ei ity

1&0 !(an lood damage assessment

To assess the flood ris# for the study area, ha)ard analysis was first done and flood *otential ma*s

under different *robabilities of occurrence were (enerated with a 2 m (rid resolution. lood events

with $, 1, 2$, $, 1 and 2 year return *eriods were used for this flood ha)ard analysis to cover

the *robable situations in a more com*lete sense. 0*atial information was (athered for this area

includin( landuse, )onin(, administrative boundary, and di(ital terrain. The related census data,

includin( data on demo(ra*hy, vehicles, commercial and industrial activities were collected for

e!*osure analysis. These collected census data are in a form a((re(ated by census tract, the basic unit

of city administration. These a((re(ated data were disa((re(ated into the 2 m 2 m cells to be

com*atible with the *reviously (enerated flood *otential ma*s. Fanduse and )onin( information was

used to assist this disa((re(ation *rocess.

The related loss functions were a**lied to these disa((re(ated data with the flood de*ths for dama(e

assessment for each cell and each cate(ory. Es a com*arison, the flood dama(e was also estimated at

the basic city administrative unit level usin( the a((re(ated census data and the results are dis*layed

as shown in i(ure 4 and Table 2.


10/12

i(ure 4. Hridbased flood ris# ma* with 2 year return *eriod in Tai*ei central area

The estimated re(ional flood dama(e for each flood event was then associated with its occurrence

*robability to construct the 5 curve for flood ris# of the city as shown in i(ure $/. This EEF can

be used as a basis for evaluation of the flood mana(ement measures throu(h withandwithout

analysis. The difference of the EEF with and without the im*lementation of a flood miti(ation

*roject could be evaluated as the annual benefit of the measure. To(ether with the annual cost

estimated for im*lementin( the *roject, the *lanner can better determine whether the *roject would be

economically viable.

Table 2. lood dama(e assessment in Tai*ei city

eturn *eriod

year/

24 hr rainfall

accumulation

mm/

'nundated

area

"m2/

'nundated area

C Total area I/

lood dama(e U0 million/

8ousehold 'ndustry O

ommerce

Total


11/12

1 3&4 2.4 .9& 93.% 34.3 1$4.:

2$ 42% 3.22 1.3 114.2 4.% 29.4

$ 4%3 4.1 1.%2 1$&.9 $1.$ 2%3.4

1 $$ $.34 2.1$ 22. %1.$ 344.9

2 $$ %.&& 2.&3 2%&.& &&.2 3::.&

i(ure $. The flood dama(e e!ceedance *robability curve for Tai*ei ity

DISC!SSIOS AD COC$!SIOS

1. The *ro*osed a**roach uses only a((re(ated census data that are com*aratively easier to collect.

E disa((re(ation al(orithm was *ro*osed to decom*ose the a((re(ated census data down to a

smaller (rid cell data model for matchin( with the flood ha)ard ma*s (enerated from flood

simulation models. 0*atial information such as landuse, )onin(, and terrain were used as

bac#(round su**ort for a more realistic decom*osition.

2. The conce*t of 5 curve was used to establish a re(ional ris# assessment at full *robability ran(e.

The EEF combined with the withandwithout analysis was also *ro*osed for better economic

evaluation amon( flood miti(ation measures.

3. The EEF can be calculated for each (rid cell instead of the re(ion as a whole. The resultin( ma*

can be ta#en as ris# ma* showin( the s*atial variation of avera(e flood ris# in the re(ion. E

sam*le ris# ma* is shown in i(ure 4 for the study area. ;ith the information of ris# s*atial

variation, current landuse can be reviewed and a more reasonable landuse *attern can be

*ro*osed for effective flood ris# miti(ation.

- ACKOW$ED%E"ET

The wor# is su**orted by the National 0cience ouncil, Taiwan N0 99291$'212/ and the

JU *roject, funded by the uro*ean ommission throu(h ramewor# 5ro(ramme &, HrantNumber 2444&.


12/12

/ REFERECES

Ernell, N. ;. 19:9. !*ected Ennual =ama(e and Uncertainties in lood re+uency stimation. J. Water Res.

Pl. Management11$,

941&.

Documents

Flood Damage Assessment in Taipei City