A rticle
A Hybrid Analytic Network Process
and Artificial Neural Network (ANP-ANN) Model
for Urban Earthquake Vulnerability Assessment
M ohsen A lizad eh 1, Ibrahim N gah 2, M azlan H ashim 3, B isw ajeet P radhan 4,5,*K and A m in B eiranvand Pour 6 0
1 D epartment of Urban Regional Planning, Faculty of Built Environm ent, Universiti Teknologi M alaysia, 81310 UTM Skudai, Johor, M alaysia; alizadeh.m [email protected]
2 Centre for Innovative Planning and Developm ent (CIPD), Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, M alaysia; b-ibrhim @utm .m y
3 Geoscience and Digital Earth Centre (INSTeG), Research Institute for Sustainable Environment, Universiti Teknologi M alaysia, Johor Bahru 81310, M alaysia; [email protected] y
4 School of Systems, M anagement and Leadership, Faculty of Engineering and Inform ation Technology, University of Technology Sydney, 123 Ultim o, New South Wales, Australia
5 D epartment of Energy and M ineral Resources Engineering, Choongm u-gw an, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul 05006, Korea
6 Korea Polar Research Institute (KOPRI), Songdomirae-ro, Yeonsu-gu, Incheon 21990, Korea; beiranvand.am in80@gm ail.com
* Correspondence: biswajeet24@gm ail.com or bisw [email protected]; Tel.: +61-295147937
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A bstract: V u ln erab ility a ssessm en t is one of th e p rereq u isites for risk an aly sis in d isaster m an ag em en t.
V u ln e r a b ility to e a r th q u a k e s , e s p e c ia lly in u r b a n a re a s , h a s in c re a s e d o v e r th e y e a rs d u e to th e p re s e n c e o f c o m p le x u r b a n s tru c tu re s a n d ra p id d e v e lo p m e n t. U r b a n v u ln e r a b ility is a re s u lt o f h u m a n b e h a v io r w h ic h d e s c rib e s th e e x te n t o f s u s c e p tib ility o r re s ilie n c e o f s o c ia l, e c o n o m ic , an d p h y s ic a l a s s e ts to n a tu ra l d is a s te rs . T h e m a in a im o f th is p a p e r is to d e v e lo p a n e w h y b rid
fr a m e w o r k u s in g A n a ly tic N e tw o rk P ro c e s s (A N P ) a n d A r tific ia l N e u ra l N e tw o rk (A N N ) m o d e ls fo r c o n s tr u c tin g a c o m p o s ite s o c ia l, e c o n o m ic , e n v ir o n m e n ta l, a n d p h y s ic a l v u ln e r a b ility in d e x . T h is in d e x w a s th e n a p p lie d to T a b riz C ity, w h ic h is a s e is m ic -p ro n e p ro v in c e in th e n o r th w e s te r n p a r t o f Ira n w ith re c u r rin g d e v a s ta tin g e a rth q u a k e s a n d c o n s e q u e n t h e a v y c a s u a ltie s a n d d a m a g e s.
A G e o g ra p h ic a l In fo rm a tio n S y s te m s (G IS ) a n a ly sis w a s u s e d to id e n tify a n d e v a lu a te q u a n tita tiv e v u ln e r a b ility in d ic a to rs fo r g e n e r a tin g a n e a rth q u a k e v u ln e r a b ility m a p . T h e c la s s ifie d a n d s ta n d a rd iz e d in d ic a to rs w e re s u b s e q u e n tly w e ig h e d a n d ra n k e d u s in g a n A N P m o d e l to c o n s tr u c t
th e tra in in g d a ta b a se . T h en , stan d ard ized m ap s co u p led w ith the train in g site m ap s w ere presen ted as in p u t to a M u ltilay er P ercep tron (M LP) n eu ral n etw o rk for p ro d u cin g an E arth q u ake V ulnerability M ap (EV M ). Finally, an E V M w as produ ced for Tabriz C ity and the level o f vu ln erab ility in vario u s zones w as obtained. Sou th and so u th east regions o f Tabriz C ity ind icate low to m o d erate vu lnerability, w h ile som e
zo n e s o f th e n o rth e a ste rn tra c t a re u n d e r critical v u ln e ra b ility c o n d itio n s. F u rth e rm o re , th e im p a ct o f th e v u ln e ra b ility o f T ab riz C ity o n p o p u la tio n d u rin g a n e a rth q u a k e w a s in clu d e d in th is an a ly sis fo r risk e stim a tio n . A co m p a riso n o f th e re su lt p ro d u ce d b y E V M a n d th e P o p u la tio n V u ln era b ility (P V ) o f T ab riz C ity co rro b o ra te d th e v a lid ity o f th e resu lts o b ta in e d b y A N P -A N N . T h e fin d in g s o f
th is p a p e r are u se fu l fo r d ecisio n -m a k e rs a n d g o v e rn m e n t a u th o rities to o b ta in a b e tte r k n o w le d g e o f a c ity 's v u ln e ra b ility d im e n sio n s, a n d to a d o p t p re p a re d n e ss stra te g ies in th e fu tu re fo r T ab riz City. T h e d e v e lo p e d h y b rid fra m e w o rk o f A N P a n d A N N M o d e ls ca n e a sily b e re p lica te d an d a p p lie d to
oth er u rb a n regions arou nd th e w o rld fo r su stain ab ility and e n v iro n m en tal m an ag em en t.
K eyw ord s: u rb a n v u ln e ra b ility ; R e m o te S e n s in g ; A n a ly tic N e tw o rk P ro c e s s (A N P ); e a rth q u a k e
v u ln e ra b ility m a p ; G IS
1. Introduction
R e s e a r c h s tu d ie s o n w o r ld w id e c h a n g e o f e n v iro n m e n t a n d s u s ta in a b ility s c ie n c e s h a v e fo u n d
v u ln e ra b ility as th e m a in c o n c e rn [1- 10] . T h e u rb a n v u ln e ra b ility is a re su lt o f h u m a n b e h a v io r w h ich d escrib es th e e x te n t o f su sce p tib ility or re silie n ce o f so cia l, e co n o m ic, and p h y sical assets to th e n atu ral d isa ste rs [11- 13] . U rb a n v u ln e ra b ility to e a rth q u a k e s h a s in cre a se d o v er th e y e a rs d u e to th e p re sen ce
o f c o m p le x u r b a n s tru c tu re s a n d u n c o n tro lle d u r b a n g ro w th . T h e m a in c a u se s o f h ig h v u ln e r a b ility o f c itie s to e a rth q u a k e s a re d u e to m a n y fa c to rs e .g ., u n c o n tro lle d u r b a n g ro w th in h ig h ly s e is m ic a re a s , im p ro p e r d is a s te r m a n a g e m e n t, h ig h e x p o s u re to in d ic a to rs o f ris k , v u ln e ra b le b u ild in g s a n d
in fra s tru c tu re s , ris in g u r b a n iz a tio n a n d p o p u la tio n g ro w th , in c is in g w e a lth m e a s u r e s , a n d th e h ig h
v u ln e ra b ility o f m o d e rn c o m m u n itie s an d te c h n o lo g ie s [14- 18] .
E a rth q u a k e v u ln e ra b ility a s s e s s m e n t m e th o d s g e n e r a lly fo c u s o n m a g n itu d e p re d ic tio n [19- 2 8 ] and stru ctu ral and g e o lo g ica l en g in e e rin g asp ects [29- 3 6 ]. H ow ever, ap art from their d ev astating effects o n b u ilt-u p areas, e a rth q u a k e s c a n h a v e sig n ifica n t im p a cts o n e c o n o m ic d e g ra d a tio n , so cial stru ctu re,
an d th e cu ltu ra l h e rita g e o f a n u rb a n area. To e ffe ctiv e ly u tiliz e a s tro n g e v a lu a tio n m e th o d fo r a n e a rth q u a k e v u ln e ra b ility a sse ssm e n t, it is n e ce ssa ry to in co rp o ra te so m e im p o rta n t v u ln e ra b ility co m p o n e n ts o f an u rb a n area, su ch as so cio -e co n o m ic, e n v iro n m en tal and p h y sical co m p o n en ts.
T h e co m p re h e n sio n an d p re p a ra tio n o f u rb a n v u ln e ra b ility d u e to e a rth q u a k e s ta k e in to a cco u n t
a w id e sc a le o f v u ln e r a b ility a s p e c ts th a t c o u ld b e m a n a g e d b y d e v e lo p in g a n in te g ra te d a p p r o a c h . T h e A rtificial N e u ra l N e tw o rk s (A N N ) [3 7 ,3 8 ] ca n p ro v id e co m p u ta tio n a l m o d e ls to assess e arth q u ak e v u ln e r a b ility d u e to u n c e rta in ty b e in g a n in h e r e n t n a tu re o f e a rth q u a k e p h e n o m e n a . A N N s y s te m s w o r k c o n s e c u tiv e ly to p ro c e s s in fo r m a tio n o f in te rc o n n e c te d u n its th a t re s p o n d to in p u ts th r o u g h
v a r ia b le s , s u c h as w e ig h ts , th r e s h o ld , a n d m a th e m a tic a l tra n s fe r fu n c tio n s [3 7 ] . E a c h u n it p ro c e s s e s in p u t fro m o th e r u n its , a n d th e n s e n d s s ig n a ls to a n o th e r u n it in th e lin k . T h is m a k e s A N N s v e r y
su ita b le fo r d e a lin g w ith p ro b le m s w h ic h re q u ire la rg e sets o f d a ta , a n d h a v e c o m p le x n o n lin e a r re la tio n s w ith m a n y d iffe r e n t a lte r n a tiv e s . A N N c a n a lso d e te rm in e c o m p lic a te d p a tte rn s in sets o f
d a ta w h ic h c o m p u ta tio n a l fo rm u la s a re u n a b le to s o lv e [38- 4 2 ] . F u r th e rm o r e , it p ro v id e s re lia b le p re d ic tio n s e v e n o n n o is y a n d u n c e r ta in d a ta [4 0 ,4 1 ] . T h e re fo re , A N N h a s th e c a p a c ity to p ro d u c e c la s s ifie d v u ln e r a b ility m a p s a r is in g fro m c o m p le x in te ra c tio n s w ith h ig h a ccu ra cy . To d e v e lo p an A N N stru ctu re b a se d o n sele cte d re sea rch in d ica to rs, it n e ed s to b e tra in e d . A n ap p ro p ria te ch o ice of tra in in g p a ra m ete rs is n e ce ssa ry fo r tra in in g A N N [4 2 - 4 4 ] . T h e sin g le m o st im p e ra tiv e lim ita tio n of
an A N N lies in its efficien cy , w h ic h re lie s h e a v ily o n th e tra in in g a lg o rith m an d n e tw o rk a rch ite ctu re. R e g re tta b ly , to d a te , n o g u id e lin e s e x is t to d e fin e b o th fe a tu re s o f th e n e tw o rk . I t is fe a s ib le to fin d th e id e a l an d o p tim a l n e tw o rk ju s t b y u tiliz in g a tria l an d e rro r p ro ce d u re [45- 4 9 ] .
T h e A n a ly tic N e tw o rk P ro c e s s (A N P ) is a to o l c a p a b le o f M u lti-C r ite r ia D e c is io n M a k in g (M C D M ), w h ic h ta k e s in to a c c o u n t o f th e c o m p le x re la tio n s h ip s b e tw e e n in d ic a to rs [4 5 ] . A N P c o n s is ts o f a n e tw o r k o f c rite ria a n d s u b -c rite ria th a t c o n tro ls c o m m u n ic a tio n , a n d a n e tw o r k o f e ffe c ts a m o n g th e e le m e n ts a n d c lu s te rs [5 0 ] . I t is a p o p u la r M C D M m e th o d , w h ic h is u s e d to
e v a lu a te th e k e y ris k fa c to rs a n d p o te n tia l ris k , re g u la te ris k le v e l a n d c o n s e q u e n c e s , as w e ll as an aly ze v a ria b le s and p re fe re n ce s o f a d e cisio n [5 1 ]. T h e la ck o f an in te g ra te d m o d e l w ith all effe ctiv e p a ra m e te rs fo r s u ch a s s e s s m e n ts lim its th e p o s s ib ility o f p o lic y -m a k in g an d d e c is io n -m a k in g to w ard
e a rth q u a k e v u ln e r a b ility a s s e s s m e n t a n d d is a s te r ris k re d u c tio n . T h is p a p e r is a r e s p o n s e to th is n e e d , a n d p ro p o s e s a n in te g ra te d m o d e l fo r th e s e is m ic v u ln e r a b ility a s s e s s m e n t o f T a b riz C ity b a s e d o n a n in te g ra te d m o d e l. T h e re fo re , it is v ita l to c o n s id e r a n in te g ra te d u r b a n e a rth q u a k e v u ln e r a b ility a s s e s s m e n t fra m e w o rk . D u e to th e n o n -a v a ila b ility o f e a r th q u a k e re c o rd s fro m 1 7 8 0 ,
an d A N N M o d e ls fo r th e a s s e s s m e n t o f u rb a n v u ln e ra b ility to e a rth q u a k e h a z a rd s ca n so lv e co m p le x
p ro b lem s o f sele ctin g s u ita b le tra in in g sites in e a rth q u a k e v u ln e ra b ility a ss e s s m e n ts , an d a d e q u a te ly co n sid e r all th e re la tio n sh ip s a m o n g th e fa cto rs a n d in d ica to rs . T h e p ro p o se d fra m e w o rk w ill a cco u n t fo r th e v u ln e ra b ility o f u rb a n e n v iro n m e n t u sin g a h o listic a p p ro a ch a t th e m u n icip a lity z o n e scale. Therefore, the A N N - A N P b ased m ethod p resen ted here m eets the requ irem ents o f earth q u ak e prediction. This is becau se cu rrent approaches for v u ln erab ility assessm ent are d ifficu lt to im p lem en t in cou ntries like
Iran. T his p ap er em p loy s a n ew hyb rid fram ew ork of A N P and A N N m o d els for constru cting a com posite social, e co n o m ic, e n v iro n m en tal, and p h y sical v u ln erab ility index. T h e d ev elop ed m o d el w a s ap p lied to a real case stu d y from Tabriz City, w h ich is situ ated in th e n o rth w e ste rn Ira n (F ig u re 1) .
Tabriz C ity is a seism ic-p ro n e p rovince w ith recu rring d ev astating earth q u ak es w h ich have resulted in h e a v y ca su a ltie s a n d d a m a g e s. It is o n e o f th e h ig h -ris k z o n e s fo r fu tu re e a rth q u a k e s in Ira n d u e to its g e o g ra p h ic a l lo c a tio n a n d g e o lo g ica l s tru ctu ra l fe a tu re s . H is to ric a l stu d ies h a v e s h o w n th a t T ab riz h a s b e e n d e v a s ta te d b y sev era l d e stru ctiv e e a rth q u a k e s (T ab le 1 ) . In v ie w o f th a t, th e re is a n e e d to g e n e r a te a lo c a l a n d n a tio n a l a s s e s s m e n t fr a m e w o r k a t th e m u n ic ip a l sc a le . U n fo rtu n a te ly , n o n e o f
th e d e s c rip tio n s b y w h ic h th e s e e v e n ts a re k n o w n is s u ffic ie n tly d e ta ile d to a llo w a n a c c u ra te a s s e s s m e n t o f d e s tr u c tio n a n d g ro u n d d e fo rm a tio n . A c c o rd in g to a p ro b a b ilis tic a n d d e te r m in is tic a ssessm e n t, seism o lo g ists b elie v e th a t a stro n g e a rth q u a k e m ig h t o ccu r in Tabriz in th e n e a r fu tu re [5 2 ] .
T h e re fo re , h a z a rd m itig a tio n a s s e s s m e n t is n e c e s s a ry to d ecre a se th e d a m a g e sev erity .
T h e m a in o b je c tiv e s o f th is p a p e r a re : (1) to d e v e lo p a h y b rid A N P -A N N m o d e l in g e o g ra p h ic in fo r m a tio n s y s te m (G IS ); (2) to a s s e s s fo u r m a in d im e n s io n s o f e a r th q u a k e v u ln e r a b ility s u c h a s so cial, e co n o m ic, e n v iro n m en ta l, and p h y sica l an E a rth q u a k e V u ln erab ility M ap (E V M ) fo r Tabriz C ity ;
a n d (3) to c o m p a re th e re s u lts w ith d a ta p ro v id e d b y P o p u la tio n V u ln e r a b ility (P V ) w ith a n a im to re d u ce th e im p a ct o f an e a rth q u a k e b y d e te rm in in g an d ca te g o riz in g th e m o st v u ln e ra b le z o n e s.
2. R elated R esearch
C o m p re h e n s iv e im p le m e n ta tio n o f th e A N P -A N N m o d e l h a s n o t b e e n re p o rted in u rb a n v u ln e ra b ility a s s e s s m e n t fo r e a rth q u a k e s. H o w e v e r, so m e o f th e c u rre n t stu d ies in re la ted field s are
s u m m a riz e d as fo llo w s. To d a te , th e re is n o g e n era l a g re e m e n t a m o n g re sea rch ers o n h o w to b u ild earth q u ak e -fo re castin g m o d els [5 3 ]. H en ce, d ifferen t k in d s o f ap p ro ach es to ex tra ctin g k n o w le d g e h av e b e e n p ro p o se d o v e r th e la s t d eca d e . M ili, H o s s e in i an d Iz a d k h a h [5 4 ] d e v e lo p e d a h o lis tic m o d e l fo r a s s e s s in g e a rth q u a k e ris k a n d d e te r m in in g p rio ritie s fo r ris k r e d u c tio n a n d m a n a g e m e n t in u r b a n
fa b ric s. T h e d e v e lo p e d m o d e l e s tim a te s th e e a r th q u a k e ris k a t e a c h u r b a n z o n e b a s e d o n h a z a rd , v u ln e ra b ility , a n d re s p o n s e ca p a city . A d d itio n a lly , a n e w in d ic a to r c a lle d " In te g r a te d E a rth q u a k e S a fe ty In d ex , IE S I" is in tro d u ced to a d d ress th e sa fe ty lev el o f u rb a n fab rics in re la tio n to e arth q u a k e s,
a n d a s s e s s th e im p a c ts o f a p p lic a b le in te rv e n tio n s o n risk . T h e p ro p o s e d m o d e l is th e n a p p lie d in tw o d is tr ic ts o f T e h ra n , h a v in g d iffe re n t p h y s ic a l a n d s o c io -e c o n o m ic c h a r a c te r is tic s , to e v a lu a te th e s a fe ty le v e l fo r e a rth q u a k e s . F o r th is p u rp o s e , th e c o n trib u tin g e le m e n ts in h a z a rd , v u ln e ra b ility , and re sp o n se ca p a city h av e b e e n assessed b ase d on lo cal co n d itio n s, and th e IE SI is d eterm in e d for each
u r b a n z o n e . In a d d itio n , th e a p p lic a b ility o f th e m o d e l to a d d re s s p o te n tia l im p r o v e m e n t m e a s u re s h a s a ls o b e e n e v a lu a te d . D e v e lo p m e n t o f a n in te g ra te d m o d e l fo r s e is m ic v u ln e r a b ility a s s e s s m e n t o f re s id e n tia l b u ild in g s to M a h a b a d C ity , Ira n w a s p e rfo rm e d b y B a h a d o r i e t a l. [5 5 ] . T h is p a p e r
p ro p o se s a n in te g ra te d m o d e l fo r th e s e ism ic v u ln e ra b ility a s s e s s m e n t o f re s id e n tia l b u ild in g s b a se d o n th e a n a ly tic a l h ie r a rc h y p ro cess (A H P ) in g e o g ra p h ic in fo r m a tio n sy ste m (G IS ). T h e m e th o d o lo g y
in te g ra te s fiv e m a in g ro u p -p a ra m e te rs— g e o te ch n ica l an d s e ism o lo g ica l, so cial, d ista n ce to d a n g ero u s fa cilities, a n d acce ss to v ita l fa cilities— w ith th e ir re la ted s u b -p a ra m eters. To e v a lu a te th e p ra ctica b ility
a n d a p p lic a b ility o f th e n e w ly d e v e lo p e d m o d e l, it w a s u s e d fo r M a h a b a d city, Iran . T h e o b ta in e d v u ln e ra b ilitie s fo r th e city w e re m a p p e d in G IS , a n d th e sa m e w e re v isu a liz e d in th e 3 D city m o d e l fo r
resid en tial b u ild in g s.
o f so cia l v u ln e ra b ility to th e e a rth q u a k e d isa ste r in S ic h u a n P ro v in ce , C h in a , b a se d o n th e ca ta stro p h e
p ro g ressio n m e th o d , w a s estab lish ed . A ro u g h se t attrib u te red u ctio n m e th o d w a s ad op ted to elim in ate irre le v a n t so cia l v u ln e ra b ility in d ica to rs a n d o p tim iz e th e p ro p o se d m o d e l. F in ally , a ca ta stro p h e p ro g re ss io n m e th o d fo r so cia l v u ln e ra b ility to e a rth q u a k e d is a s te r w a s d e v e lo p e d to o v e rco m e th e su b je ctiv ity o f th e in d e x w e ig h t a s s ig n m e n t o f so cial v u ln e ra b ility in d ica to rs in th e cu rre n tly -u se d so cia l v u ln e ra b ility a s s e s s m e n t m e th o d . T h e a p p lic a tio n o f th e m e th o d to S ic h u a n P ro v in c e in d ica te s
large reg io n al d ifferen ces in term s o f social v u ln erab ility to earth q u ak e d isasters. K arim zad eh et al., [5 7 ] fo llo w e d a n in d ire c t m e th o d to p ro d u ce a V s 3 0 m a p o f Ira n fro m g e o lo g ic a l a n d to p o g ra p h ic a l d ata. T h e o u tp u ts in d icate th a t th e h y b rid V s3 0 m ap h as b e tte r p e rfo rm a n ce th a n a sin g le to p o g ra p h y -b a se d V s 3 0 m a p . T h e a m p litu d e m a p , d e riv e d fro m V s 3 0 a n d g e o lo g y m a p s , is th e n u s e d fo r se ism ic
m ic ro z o n a tio n o f T ab riz C ity, a n d th e e x te n t o f g e o g ra p h ic a l d is trib u tio n o f d a m a g e fo r a p o ssib le d e te rm in is tic sce n a rio w a s in v e s tig a te d th ro u g h co n s id e rin g d iffe re n t fra g ility c u rv e s to d e scrib e th e d a m a g in g b e h a v io r o f o rd in a ry b u ild in g ty p e s in th e city. A v a r ie ty o f d a ta to id e n tify th e m o s t
v u ln e ra b le a re a s in B u c h a r e s t fo r th e e a rth q u a k e w a s in v e s tig a te d b y [5 8 ] . S o c io -e c o n o m ic d a ta fro m c e n su se s in 2 0 0 2 a n d 2 0 1 1 w e re u s e d to g e n e ra te a n o v e ra ll sp a tia l v u ln e ra b ility in d e x , w h ile o th e r v a ria b le s su ch as e a rth q u a k e scen a rio s and d istan ce to re silie n ce -e n h a n cin g p o in ts in sp a ce (e.g., p ark s, fire s ta tio n s, e tc.), h e lp e d to fin e -tu n e th e a n a ly sis a n d o ffe re d a co m p re h e n siv e p ictu re o f w h e re
v u ln erab ility h o tsp o ts cou ld b e fo u n d in an u rb a n en v iro n m en t. T h e top three m o st v u ln erab le h otsp ots are a n a ly z e d , a n d tw o u n d e rly in g re a so n s fo r th e ir v u ln e ra b ility are p ro p o se d a n d d is cu ss e d in m o re d etail, nam ely, ed u catio n and co n n ected n ess. T h ey ap p lied u n certain ty and sen sitiv ity an alyses to assess the stab ility o f the resu lts for v u ln erab ility hotsp ots. T h e g eneral ou tcom e of the research is an increase in
the ov erall so cioecon o m ic v u ln erab ility in the city in spite o f the u p w ard econ om ic trend in the period of tim e u n d e r an aly sis.
M o re recen tly , Z e b a rd a s t [5 9 ] p re sen ted th e d e v e lo p m e n t o f a h y b rid facto r a n a ly sis an d an aly tic n e tw o r k p ro c e s s m o d e l fo r a g g re g a tin g v u ln e r a b ility in d ic a to rs in to a c o m p o s ite in d e x o f so cia l
v u ln e r a b ility (S V ) to e a rth q u a k e h a z a rd s . T h e o b je c tiv e o f th e s tu d y w a s to c o n s tr u c t a h y b rid FA a n d A N P (F 'A N P ) m o d e l fo r s o c ia l v u ln e r a b ility a s s e s s m e n t a n d a p p ly it a t th e c o u n ty le v e l in Ira n . In a n o th e r p a p e r, P r a d h a n [6 0 ] u s e d re m o te s e n s in g a n d a G IS a n d A N N m o d e l to p ro p o s e
a la n d s lid e h a z a rd a n d ris k a n a ly sis m e th o d . G IS a n d im a g e p ro c e s s in g to o ls w e re u s e d to a s s e m b le a s p a tia l d a ta b a s e fro m to p o g ra p h ic a l, g e o lo g ic a l a n d s a te llite im a g e s d a ta . P a n a k k a t a n d A d e li [61] p re d icted e a rth q u a k e tim e an d lo c a tio n in S o u th e rn C a lifo rn ia , th is tim e u s in g a n im p ro v e d v e rs io n o f th e re cu rre n t n e u ra l n e tw o rk . In p articu lar, th e y co m p u te d sev eral sets o f e a rth q u a k e s re g a rd in g th e la titu d e a n d lo n g itu d e o f th e e p ice n tra l lo ca tio n , as w e ll as tim e o f o ccu rre n ce o f th e fo llo w in g
e arth q u ak e. A p ro bab ilistic n eu ral n e tw o rk w a s also tested .
3. M aterials and M ethods
3.1. S tu d y A rea C h a ra cteristic
T ab riz C ity, w ith a p o p u la tio n o f m o re th a n 1 .5 m illio n p e o p le a n d c o n s is tin g o f n in e re g io n s, is lo ca te d in th e n o rth w e s te rn p a rt o f Ira n (F ig u re 1 ). It is th e se co n d la rg e s t c ity o f Ira n in te rm s o f la n d are a , a n d e n c o m p a ss e s a b o u t 2 5 k m2 a re a o f o ld te x tu re . T h e N o r th T ab riz F a u lt (N T F ) is
th e m o s t n o tic e a b le te c to n ic stru ctu re in th e v ic in ity o f T ab riz C ity (F ig u res 2 a n d 3 ) [6 2 ] . It e n circle s a n a re a o f e x tre m e d e fo rm a tio n . T h e se is m ic ity is situ a te d b e tw e e n a c o u p le o f fo ld -a n d -th ru s t b e lts o f th e C a u c a s u s to th e n o rth a n d th e Z a g ro s M o u n ta in s to th e s o u th , c o v e r in g a d is ta n c e o f 1 5 0 k m in th e N o rth w e s t-S o u th e a s t d ire c tio n in th e N o r th w e s t o f Ira n [63,6 4 ]. A lth o u g h th e N T F h a s b e e n
se is m ica lly in a c tiv e o v e r th e p a s t fe w d e c a d e s , it h a s h is to ric a lly g e n e ra te d la rg e su rfa ce -ru p tu re e a rth q u a k e s (T able 1) .
In th e la s t 6 5 y e a rs , th re e la rg e e a rth q u a k e s h a v e ru p tu re d th e N T F sy ste m a n d a d ja c e n t
o n th e s o u th -e a s te rn N T F w ith a su rfa ce ru p tu re le n g th o f m o re th a n 3 5 k m . T h e T ab riz e a rth q u a k e
(M ~ 7 .4 ) occu rred in 1780 on the n o rth -w estern N TF, w ith su rface ru ptu re len g th of 42 km . M aran d -M ish u e a rth q u a k e rM'-o6.3) o ccu rred in 1786 oil th e M ish u rev erse fau lt an d th e S u fia n se g m e n t [6 5 ].
46°6'«"i: m r c w w o-e «w e
45°59,0"F. « W t K W E « “27't"F.
Figure 1. The geographic location of Tabriz City in the NW of Iran.
46°5'30"E
46°12'0"E
46°18'30"E
46°25'0"F.
, i n . --- --- - - i
4 6 ° 5 '3 0 " E 4 6 ° I 2 ’0 " F . 4 6 ° 1 8 '3 0 " E 4 6 ° 2 5 ,0 " E
Figure 3. Geology Map of Tabriz City. Legend: M m g2 = Interlayer of greenish grey marl associated w ith interlayer of1 gypsum - baring; sandy marl; M sc5 = Interbedded red conglomerate w ith sandstone and red marl; M sm 4 = Sandstone and red marl; Pldt = Diatomic and fish interbedded with fine particles sediment; Plqc = Interlayer of semi-hard conglom erate associated w ith sandstone and pumice; Plqc = Interlayer of semi-hard conglom erate associated w ith sandstone and pumice. Qal = Quaternary alluvium; Qt2 = Young terrace and alluvium deposits [62].
Table 1. List of historical earthquakes of Tabriz up to 1900 AD (Source A: [63] and B: [65]).
Number Year Fatalities Source Description
1 634 - B
2 694 - B
3 7465 - B
4 838! - B
5 845» - B
6 8585 - B-A Half of the town was destroyed
7 8 6 8 - B
8 949 - B
9 1 0 2 0 - B
1 0 1040 - B
1 1 1042 40,000 A-B Most of the important structures were destroyed.
1 2 1272 - B Many houses were destroyed in Tabriz.
18 aftershocks occurred in the first 24 h. Aftershocks continued for 4
13 1273 250 A
months.
14 1314 - B
15 1345 - A No destruction occurred.
16 1441 - B This event was probably related to Wan-Nimroud earthquake that had been associated with volcanic activity.
17 1527 - B
18 1633 - B
19 1640 - B
2 0 1641 1 2 0 0 A-B The earthquake happened between Tfbeiz and Urmia Lake. Osko, Khosrowshah, and Dehkharghan -were destroyed.
2 1 1668 - B Tabriz and some parts of Caueasus were destroyed.
2 2 1717 700 A Midnight earthquake destroyed more than 4000 ho uses. Many houses and monuments were destroyed. Rapture length 23 1721 - A-B reached to more than 55 km (between Tykmehdash and Tabriz) A lot
of damages occurred in the area between Shebli and Gharebaba.
24 1727 70,000 A-B
Table 1. Cont.
Number Year Fatalities Source Description
28 1843 - A-B A series of earthquakes of different intensities have been recorded by Khanikov.
29 1870 - B An earthquake shook Tabriz City.
30 1896 - B An earthquake was felt in Tabriz.
31 1896 - B An earthquake was felt in Tabriz.
3.2. D ata A cq u isitio n , C lassification a n d S tan d a rd iz a tio n
V u ln e r a b ility m a p s a re d iffic u lt to p ro d u c e w ith o u t ta k in g in to a c c o u n t o f th e c rite ria a n d in d ica to rs, w h ich cau se th e h e te ro g e n e ity o f th e stu d y area [6 6]. This is the m o st vital p art o f the overall a p p ro a ch , w h ic h en su re s th a t th e sele cte d crite ria a n d th e in d ica to rs are a d e q u a te to re fle ct th e o v era ll
v u ln e ra b ility o f u rb a n areas in T ab riz City. S e le ctin g in d ica to rs is a n e x tre m e ly tim e -c o n s u m in g p a rt o f th e m e th o d , b e c a u se it co n sists o f co n stru ctin g an d p re p a rin g a G IS sp atial d a ta b a se th a t w ill la ter b e u se d d u rin g e a rth q u a k e v u ln e ra b ility a n a ly se s an d serv e d as in p u t to u rb a n e a rth q u a k e scen ario s. T h e re are sev era l crite ria a n d in d ica to rs e m p lo y e d fo r u r b a n v u ln e ra b ility a sse ssm e n ts (S e e T a b le 2 ) .
A c co rd in g to th e p u rp o se o f th e stu d y, d a ta co lle c tio n w a s co n d u cte d b a se d o n th e in d ica to rs d eriv ed fro m th e lite ra tu re a n d a n e x p e r t q u e s tio n n a ir e su rv ey . A s m e n tio n e d in T ab le 2 o f th is stu d y, 4 4 in d ica to rs a sso cia ted w ith u rb a n v u ln e ra b ility to e a rth q u a k e h azard in T ab riz C ity w e re p re sen ted . T h e a c a d e m ic s ta ff o f th e d e p a r tm e n t o f g e o g r a p h y a n d u r b a n p la n n in g (T a b riz 's U n iv e rs ity ) w e re
c h o s e n as e x p e rts fo r th is stu d y . T h e e x p e rts w e re a s k e d to r a n k th e im p o r ta n c e a n d re le v a n c e o f d isco v ered v u ln e ra b ility in d ica to rs a sso ciated w ith u rb a n v u ln e ra b ility to th e e a rth q u a k e in Tabriz C ity fro m th e m o s t im p o r ta n t to th e le a s t [ 67] . A s a re s u lt, 2 0 in d ic a to rs w e re h ig h lig h te d as v u ln e ra b ility in d ica to rs a sso cia ted w ith u rb a n v u ln e ra b ility to th e e a rth q u a k e in T ab riz C ity. T h e im p o rta n ce in d e x
o f th e in d iv id u a l in d ic a to rs w a s c a lc u la te d b a s e d o n E q u a tio n (1 ), th e ra n g e o f re la tiv e im p o r ta n c e in d e x (R II) is fro m ze ro to o n e, and in d ica to rs w ith R II o f less th a n 0.50 are re m o v ed fro m th e research.
R e la tiv e Im p o rta n c e In d e x :
5 E W i
(1)
w h e re ,
W : W e ig h t g iv e n b y re sp o n d e n ts to e a ch fa cto r an d ra n g e b e tw e e n 1 an d 5,
A : M a x im u m w e ig h t, in th is ca s e , A = 5,
N : N u m b e r o f re sp o n d e n ts.
A s sh o w n , 2 4 in d ica to rs w h ic h h a d o b ta in e d th e R e la tiv e Im p o rta n c e In d e x (R II) w ith v a lu e s o f less th a n 0 .5 0 w e re o b ta in e d ; th e re s t w e re e m p h a s iz e d as a lm o s t e q u a lly im p o r ta n t
(R II > 0 .5 0 ). A s h ig h lig h te d [68- 70], th o se in d ica to rs w ith less th a n 0 .5 a re c o n sid e re d u n im p o rta n t. T h erefo re, th e y ca n n o t b e co n sid ere d fo r an aly sis.
M a th e m a tic a l m e th o d s fo r d a ta cla ss ifica tio n b a se d o n e q u a l in te rv a ls, m a n u a l o r n a tu ra l b rea k s,
o r s ta tis tic a l c o n s id e r a tio n , a re d e fa u lt p ro c e s s e s in G IS s o ftw a re [7 1 ] . T h e m a n u a l cla ssifie r m e th o d h as b e e n ap p lied to cla ssify th e v a lu e s into fiv e d ifferen t v u ln era b ility classes. Initially, fo r th is p u rp o se, th e cla ssifica tio n o f all requ ired lay ers b a se d on th e d en sity o f b u ild in g s, resid en tial b u ild in g , b u ild in g s floors, m aterials, q u ality o f b u ild in g s, age o f b u ild in g s, co m m ercial b u ild in g s, and the n u m b er o f literate
p e o p le , e m p lo y e d p e o p le , u n e m p lo y e d p e o p le , p o p u la tio n , h o u s e h o ld a n d size o f b u ild in g b lo ck s, is re q u ired . T h e lo g ic o f th e s e fa cto rs is sim ila r to a b ig g e r d e n sity le a d in g to a g re a te r v u ln erab ility .
T h e o th er m e tric o f classificatio n is th e d istan ce to th e area su ch as road n e tw o rk , fau lts, d a n g er cen ters,
relief centers, and op en spaces. W ith the excep tion o f the slo p e th at is represented in p ercen t and geology, all the featu res o f th e lay ers w ere d ivid ed in to five classes. To calcu late density, a k ern el d en sity fu n ction
applied in the A rc G IS en v iron m en t (version 10.3). H ow ever, to calcu late slope, a D igital E lev ation M o d el
(D EM ) (generated from con tou rs on 1:50,000 to p ograp h ical m ap s) w a s u sed , and classificatio n w as b ased o n th e p e rce n ta g e . A g e o lo g y m a p w a s e v a lu a te d b y e x p e rt ju d g m e n t an d b a se d o n th e fe a tu res o f te x tu re , s to n e ty p e , sto n e m a te ria l, so il ty p e , w a te r p e rm e a b ility , a n d a lso th e p re se n ce o f fa u lts an d fractu res. A ll tw e n ty in d ica to rs (q u a n titie s and q u a litie s) (se e T ab le 3) w e re co n v e rte d to ra ste r fo rm a t in th e A rc G IS e n v iro n m e n t b y u s in g th e fe a tu re to raster, v e c to r to ra s te r a n d / o r p o ly g o n to raster.
Table 2. Sum m ary of the aforem entioned and relevant literature according to the m ain indicators w hich influence urban earthquake vulnerability.
Criteria Indicators- Description Scholars
Physical
1. Building Density 2. Residential Density 3. Distance to road network 4. Distance to open space 5. Distance to police stations 6. Size of building block density 7. Building's floor density 8. Quality of buildings density 9. Distance to relief centers 10. Distance to Danger centers 11. Buildings' Materials density 12. Age of building density 13. Commercial building density
[72- 82]
Environmental
14. Percent of Slope 15. Features of geology
16. Average acceleration values for medium magnitude earthquake 17. Aspect
18. Drainage 19. Distance to fault
[82- 85]
Social
20. Population density
21. Percent of population under 6 years old 2 2. Household density
23. Percent of population over 65 years old 24. Literate People density
25. Ratio of widows in female population 26. Women with many children
27. Percent population with health insurance coverage 28. Percent of the population with telephone access 29. Percent females participating in labor force 30. Percent of housing units with bathroom 31. Percent of housing units with kitchen 32. Percent of population with disability 33. Percent of population who are migrants 34. Dentist per 100,000 population
35. Specialist physician per 100,000 population 36. Hospital beds per 1 0 0 , 0 0 0 population 37. Dwelling population density on census unit
[86- 93]
Economic
38. Employed People density 39. Unemployed people density 40. Degree of occupancy per room 41. Room area per person
42. private residences with more than 5 rooms 43. Percent of homeownership
44. Per capita household income
Table 3. Selected Criteria and Indicators for Vulnerability Assessm ent in this Study.
Criteria Indicators-D escription A bbreviation Scale Source Scholars
Building Density BD 1.2500 4
Residential Density RD 1.2500 4
Distance to the road network DRN 1.2500 1
Distance to open space DOS 1.2500 1
Size of buildingblock density 4
Building's floor density SBBD 1.2500 4
Physical Quality of buildings density BFD 1.2500 5 [96- 105]
Distance to relief centers QBD 1.2500 1
Distance to Danger centers DRC 1.2500 1
Buildings' Materials density DDC 1.2500 4
Age of building density BMD 1.2500 4
Commercial building densi
ty
A BD 1.2500 4C BD 1.2500 14
Percent of Slope PS - 6
Environmental Features of geology PG 1.1 0 0 , 0 0 0 42 [105,106]
Distance to fault DF 1.1 0 0 , 0 0 0 41
Population density PD 1.1 0 , 0 0 0 3
Social Household density HD 1.1 0 , 0 0 0 3 [107- 110]
Literate People density LPD 1.1 0 , 0 0 0 3
Employed People density Economic
Unemployed people densrty
EPD UPD
1.2500 1.2500
s
s ^ 08 -1 1 2] 1. Consulting engineering of Tehran Padil. http://www.tehranpadir.com, 2. Iranian Geological organization. http://www.gsi.ir/, 3. Census Center of IRAN. http://www.amar.org.ir/, 4. Department of road and Urbanity (East Azerbaijan Province). http/Z/ea-mrud.irA 5. The municipality of Tabriz City. /tt/://wwwtabriz.ir, 6. DEM 30 m Aster, hiip://earthexpiorer.usgi .gov/.
E a c h o f in d ica to rs h o ld s a d e fin ite ra n g e scale v a lu e ; h e n ce , it n e e d s to b e stan d ard ize d .
Sta n d a rd iz a tio n is a p ro ced u re to d eterm in e m e m b ersh ip v a lu e accordii/g to the/ u sa g e o f eaph criterio n . T h u s, all th e tw en ty ind icato rs w e re stan d ard iaed a i this erage. S u itab le w p ights b ased on im p o rtan ce in the earthq u ake hazard v u ln erab ility w ere given , n am ely very unfavorable, unfavorable, m oderate, fa v o ra b le and
v ery fa v o r a b le . F ig u re 4 show u th e sta n d a rd iz e d in p u t la y ers d eriv ed fro m th e G IS p ro ce d u re fo r
th e in d icato rs u sed in th is etu d y fo r Tabrip Ci/y.
a. Age of Buildings (DEN) b. Danger Centers (DIS) c. E m p lo y ee P eop le (D EN )
cl. F a u lt (D IS ) e. B u ild in gs F lo o rs (D EN ) f. Geology
j
9
'
W
i
J
j
p
i
g. H ousing (D EN ) h. H ousehold (D EN ) i. L itr a te People (D EN )
Figure 4. Standardized input layers derived from GIS procedure for the indicators usee;! in this study; (a) Age of buildings density; (b) Danger centers; (c) Employed densfty; (d) Distance to fault (e) Buildings floors; (f) Features of geology (g) Housing density; (hf Household density; (i) Literate density; (j) Size of building; (k) Building materials; (l) Distance to open spaces; (m) Population density; (n) Quality of buildings; (o) Distance to rescue centers; (p) Buildings density; (q) Percentage of slope; (r) Distance to roads network; (s) Unemployed people; (t) Commercial density.
3.2 .1 . D e s c rip tio n o f t h f S e le cte d In d ica to rs
E n v iro n m e n ta l In d ica to rs
G eolog ;)! o f T a b riz : T h e c ity o f T a b riz is g e o lo g ic a lly c o m p o s e d oW re d m a rl a lo n g w ith y o u n g a llu v ia l b a rra c k s a n d rid g e s a n d sto n e s . T h e re e m a ris c o m p ris e o f a n a lte r n a tio n o f g re e n , g ra y a n d re d m a rls w ifh th e in n e r ta y e rs o1 ta n d y , g y p s e o u s a n d s a ltin e m a rls . H o w e v e r, th e c o n te m p o r a r y a llu v ia l c o n s is ts o f c la s tic g ra n u le s e d im e n ts w ith la y e rs o f d ia to m fish . In a d d itio n , th e s e m i-rig id c o n g lo m e r a te c o n s is ts o f la y e rs o f s a n d s to n e s , p u n s , p y ro c la s tic ro c k s , b a s ic a n d u ltra -b a s ic s to n e s ,
an d red c o n g lo m e ra te w ith an a lte rn a tio n o f s a n d sto n e an d red m a rl [9 7] .
P e r c e n t o f s lo p e : B a s e d o n its p o s itio n th e c ity o f T a b riz is id e a lly lo c a te d o n la n d s w ith le ss th a n 5 % g ra d ie n t. C o n s e q u e n tly , la rg e n o r th e r n p a rts o f th e c ity in c lu d e m a rg in a l z o n e s w ith h ig h
d o n o t s h o w fa v o u ra b le c o n d itio n s in te rm s o f th e g ra d ie n t. H o w e v e r, b e tte r c o n d itio n s e x is t d u e to
th e re la tiv e ly larg e d ista n ce fro m fa u lt lin e s, lo w p o p u la tio n an d s tru ctu ra l d e n sity [8 3 ] .
D is ta n c e to fa u lt: O n e o f th e m o s t im p o r ta n t m e a s u re s to p r e v e n t th e d e v a s ta tin g e ffe c ts o f e a rth q u a k e s is to a v o id h ig h r is k z o n e s . T h e re fo re , th e c h o ic e o f lo c a tio n is a v e r y c ru c ia l ste p in d esig n in g b u ild in g s or p la n n in g for s ettle m e n ts in seism ic p ro n e areas. T h e im p o rta n ce o f site lo ca tio n
is a v ita l a p p ro a ch to risk a s s e s s m e n t an d h e n c e h ig h risk areas sh o u ld b e a v o id e d [1 0 6 ] .
S o c ia l In d ica to rs
T h e p o p u la tio n d e n sity : D u r in g th e d e c a d e s (1 9 7 6 - 2 0 1 1 ), th e p o p u la tio n d e n s ity in th e n o r th ,
n o r th -e a s t (B a g h m is h e h a n d R o s h d ie h ) a n d n o r th -w e s t (E r a m to w n ) h a s in c re a se d . In o th e r w o rd s , in c re a s in g p o p u la tio n d e n s ity h a s u n fo r tu n a te ly o c c u rre d to w a rd th e N o r th T a b riz F a u lt (N T F ).
T h e re fo re , s ig n ific a n t se c tio n s o f th e p o p u la tio n a re s u r ro u n d e d b y m a jo r a n d m in o r fa u lt b ra n c h e s . T h is in d ica te s th a t z o n e s 1, 4 and 5 are lo ca te d in th e rem o te e a rth q u a k e p ro n e areas, w h e re a s z o n e s 2 an d 3 s h o w b e tte r circu m sta n ce s [1 0 8 ] .
H o u s e h o ld d e n s ity : H o u s e h o ld v u ln e r a b ility a s s e s s m e n ts a re ty p ic a lly u s e d b y s c ie n tis ts a n d p o licy m a k e rs to ascerta in th e p o ten tia l im p acts o f e n v iro n m en ta l ch an g e in p a rticu la r p laces, and p lan e ffectiv e re sp o n se s d u rin g crises. T h erefo re a ssessin g th e v u ln e ra b ility o f h o u seh o ld p o p u la tio n d en sity
to e a rth q u a k e is c ru c ia l. T h is is b e c a u s e h ig h h o u s e h o ld d e n s ity in c re a se s v u ln e r a b ility p a rtic u la rly w h e n d is p a ritie s e x is t b e tw e e n h o u s e h o ld s an d re sid e n tia l b u ild in g s iz e [8 8,1 1 0] .
L ite r a te p e o p le d e n sity : L ite r a c y its e lf c a n n o t re d u c e o r in c re a s e th e v u ln e r a b ility c a u s e d b y a n e a rth q u a k e . H o w e v e r, h ig h e r lite ra c y le v e ls c a n ra is e a w a r e n e s s a b o u t h a z a rd a n d im p ro v e re s p o n s e to o fficia l a la rm s in cris e s p e rio d s in c o m m u n itie s . F u r th e rm o r e , e d u c a tio n c a n p o te n tia lly
e n h a n c e k n o w le d g e an d p e rc e p tio n o f risk s an d a p p ro p ria te re sp o n se s d u rin g d isa ste rs [1 0 7 ] .
E co n o m ic In d ica to rs
E m p lo y e d p e o p le d en sity : T h e h ig h e s t d en sity o f e m p lo y e d p e o p le on th e av e ra g e w a s o b serv ed in z o n e s 1, 4 and 5, d esp ite th e u n su ita b le co n d itio n to fa u lt lin e , u n d e sira b le d em o g ra p h ics and textu re
o f u r b a n h o u s in g . H e n c e , it c a n b e in fe rre d th a t fu ll tim e e m p lo y m e n t d o e s n o t g u a r a n te e d e s ira b le c o n d itio n s in th e z o n e s e x a m in e d d e s p ite th e s ig n ific a n c e o f in c o m e . H o w e v e r, o n ly h o u s e h o ld jo b s ta tu s is c o n s id e re d s u fficie n t d u e to th e la c k o f in co m e sta tis tics o f h o u s e h o ld s [9 3 ] .
U n e m p lo y e d d e n sity : S o c io -e c o n o m ic c o n d itio n s h a v e s ig n ific a n t im p a c t o n v u ln e ra b ility .
H e n ce , research on e co n o m ic v u ln e ra b ility p rin cip a lly h ig h lig h t in co m e (or lack of) as k e y ch aracteristic o f th e d iffe ren tial a sp e cts o f d isa ste rs. F u rth e rm o re , lo w -in co m e g ro u p s are ty p ica lly m o re ex p o sed to o b sta cle s d u rin g th e re sp o n se , reco v ery , an d re co n stru ctio n p h a s e o f d isa ste rs [1 1 1,1 1 2] .
P h y s ic a l In d ica to rs
B u ild in g d en sity : O n e o f th e m o st im p o rta n t p o licie s u n d e rta k e n u n d e r th e seco n d fiv e-y ear p lan fo r s o c io -e c o n o m ic a n d c u ltu ra l d e v e lo p m e n t in Ir a n a im s to lo w e r b u ild in g c o n s tr u c tio n d e n s ity in citie s . A s a re s u lt, la n d a llo c a tio n fo r th e h o u s in g s e c to r p a r tic u la r ly in lo w -d e n s ity re g io n s w ill b e ab rid g ed . T h is b a se d o n th e co n sid e ra tio n th o se facto rs su ch as u rb a n p o p u la tio n g ro w th , h ig h co st of
u rb a n in fra s tru ctu re s and la n d s co n s tra in ts fo r fu tu re e x p a n sio n in citie s in flu e n ce d e n sity [3 8 ] . R e s id e n tia l b u ild in g s d e n s ity : L a n d u s e a n d n ig h ttim e p o p u la tio n d e n s ity a re im p o r ta n t co n sid e ra tio n s fo r v u ln e ra b ility stu d ies. In o th er w o rd s, d u rin g an e a rth q u a k e , th e h ig h e s t n u m b e r o f ca su a lties o ccu r at n igh t. T h e re fo re , th e ch ara cteristic featu res o f th is ty p e o f u se s are g re a tly im p o rta n t
as p re s e n te d in th is re s e a rc h . C o n s e q u e n tly , a n in c re a s e in th e n u m b e r o f re s id e n tia l u n its m e a n s r e d u c tio n o f o th e r u s e s s u c h as o p e n s p a ce s fo r c irc u la tio n a n d e s c a p e . T h e re fo re , r e d u c in g d e n s ity an d p ro v id in g sp a c e s fo r fre e m o v e m e n t w ill re d u ce v u ln e ra b ility [75- 1 0 1 ] .
C o m m e rc ia l b u ild in g s d e n s ity : C o m m e rc ia l sp a c e s a re im p o r ta n t b o th fro m a n e c o n o m ic a n d
p ro sp e rity . In c o n tra s t, o v e r in c re a s in g d e n s ity in s u c h s p a c e s w ill in c re a s e v u ln e r a b ility d u rin g
e a rth q u a k e s [9 9 ] .
D is ta n c e to re lie f c e n te rs: T h e p ro x im ity to re lie f c e n te rs is a n im p o r ta n t fa c to r d u rin g a n d a fte r the d isaster (crisis). T his issu e is m ore critical to d iscu ssion s on v u ln erab ility cau sed b y e arth q u ak es since m o st d eath s from bu rial u n d er b u ild in g d eb ris or in d irectly th rou g h fire ou tbreaks. H ow ever, the su rviv al
o f ca s u a ltie s c a n b e g re a tly e n h a n c e d b y p ro v isio n o f a d e q u a te re s cu e a n d re lie f stru ctu res s u ch as h o sp ita ls, m e d ica l ce n te rs and fire fig h tin g statio n s [3 8 ,9 7 ,9 8 ] .
D is ta n c e to d a n g e r ce n te rs : T h e e a rth q u a k e s c a n le a d to a c c id e n ts s u c h a s fire , la n d s lid e , e x p lo sio n o f fu el tan k s and d am s b rea k in g am o n g oth ers. T h e re fo re , p ro x im ity to h ig h -risk areas su ch
as fu el ta n k s, w a te r ta n k s, g a s s ta tio n s , h a v e tre m e n d o u s im p a cts on v u ln e ra b ility [1 0 1] .
D ista n ce to o p en sp ace: T h e lo ca tio n and d istrib u tio n o f o p en sp a ce s can g re a tly re d u ce p o ten tia l v u ln e ra b ility . E a rth q u a k e s ty p ic a lly d a m a g e lo w q u a lity s tru c tu re s in a s h o rt p e rio d . C o n s e q u e n tly , b u ild in g s w ith fu lly o ccu p ied re sid e n ts are m o re v u ln era b le co m p are d to o ccu p a n ts in o p en sp a ce s [8 0 ] . D istan ce to street n e tw o rk : T h e n etw o rk of streets is also an im p o rtan t factor in d isaster m an agem en t.
F u rth e rm o re , cla ssifica tio n o f th e n e tw o rk o f streets b y w id th is m o re im p o rta n t th a n th e p e rfo rm a n ce sy ste m o f th e n e tw o rk in th e c o n te x t o f v u ln e ra b ility to e a rth q u a k e s. In th e m ic ro -z o n a tio n sch e m e o f T ab riz, w h ic h w a s p re p a re d b y co n s u lta n t e n g in e e rs o f T eh ran -P ad ir, th e c ity 's streets are d iv id e d in to
tw o n am e ly ; first-g ra d e street (co llectin g ) and d istrib u tin g streets) [3 8 ,9 7 ,9 8 ] .
Q u a lity o f b u ild in g s d en sity : T h e q u ality o f n e w ly co n stru cte d , rep aired or d estro y ed b u ild in g s is a m a jo r in d ica to r fo r v u ln e ra b ility asse ssm e n t. B a sed o n th is, p a rts o f z o n e s 2 ,3, 4 an d n o rth e rn p arts o f th e c ity c o m p risin g z o n e s 1 an d 5 a lso sh o w e d u n fa v o u ra b le c o n d itio n s [7 7 ] .
B u ild in g s m a te ria ls d e n s ity : T h e s e is m ic r e s is ta n c e o f b u ild in g s p la y s a k e y ro le in p ro te c tio n a g a in s t e a rth q u a k e s . M o s t e a r th q u a k e c a s u a ltie s a re d u e to th e ru p tu re a n d c o lla p s e o f b u ild in g s . In a d d itio n , th e d e s tru ctio n o f b u ild in g s d u rin g e a rth q u a k e s m a y also b e d u e m a n -m a d e p h e n o m e n a
s u ch as e c o n o m ic sta g n a tio n s an d s o cia l co lla p se s [9 8 ,9 9 ] .
A g e o f b u ild in g s d en sity : In g e n era l, th e age o f b u ild in g s ca n n o t in d ica te th e q u a lity reg ard less of th e m a te ria ls u se d as o b se rv e d u s in g th e m e th o d o lo g y o f th e K e rn e l m o d e l. B y in c re a sin g th e v a lu e s
o b ta in e d m o re u n d e s ir a b le c o n d itio n s c a n b e e x p e c te d . C o n s e q u e n tly , z o n e s l a n d 5 a re lo c a te d in re la tiv e ly w o r s e c o n d itio n s . In a d d itio n , z o n e 4 h a s s im ila r c o n d itio n s w ith o n ly s lig h t c o n n iv a n c e .
H o w e v e r, o th e r a reas h a v e re la tiv e ly fa v o u ra b le c o n d itio n s e x c e p t in a fe w ca se s [1 0 3 ].
B u ild in g s flo o r d e n s ity : T h e v u ln e r a b ility o f b u ild in g s in c re a s e s w ith in c re a s e in th e h e ig h t
a n d n u m b e r o f flo o rs. A t p re s e n t, it is n o te w o r th y to s ta te th a t d e s p ite a d v a n c e m e n ts in b u ild in g te c h n o lo g y , h ig h e r a ltitu d e d o e s n o t d im in is h v u ln e ra b ility . In a n y c a s e , th e n u m b e r o f flo o rs o n
b u ild in g s is also an im p o rta n t fa cto r in s e ism ic v u ln e ra b ility [78, 1 0 5 ] .
S iz e o f b u ild in g s d en sity : T h e g e o m e try o f la n d a n d its p ro p e rtie s n e ed to b e c o m p re h e n siv e ly
asse sse d d u rin g e v a lu a tio n a n d s e g m e n ta tio n o f la n d s. T h e e ffe c t o f b u ild in g sp e cifica tio n s d irectly in flu e n ce stru ctu re p e rfo rm a n c e , co n stru ctio n ch a ra cte ristics, a n d ro a d n e tw o rk s v ital fo r v u ln e ra b ility
in d e x e v a lu a tio n . In a s s e ssin g e a rth q u a k e v u ln erab ility , th e siz e a n d g e o m e trica l sh a p e o f th e la n d s sch e m e are cru cial. Typically, v u ln e ra b ility is lo w e r fo r p arce ls o f la n d w ith larg e b u t re g u la r sh ap e s
and sizes [74- 7 6 ].
3.3. T ran sferrin g L ay ers to ID R IS I S oftw are
In this step, all the stan d ard ized layers p rod u ced in the p reviou s stage w ere tran sferred to the ID R ISI
Selected vulnerability indicators from literature review
• B uilding D en sity • H o u sin g D ensity ' D istance to Road net^odc
1 D is tance to op^n spaces • Size o f building blocks
D ensity
» B uildings' floor D ensity • Q uality o f building D ensity
1 D is tance to rescue centres » Dis tance to D anger centres • M aterials o f Buildings
D ens i tv
• Slope Percent
• Features of
Geology
• Distance to Fault
• Population Density
• Household Density
• Density of literate
people
• Density of Em ployed people • Density of
Unemployed people • Com m ercial
Density
Earthquake V ulr.erability Map izvxn
T ra n sfer to ARC GIS and C onvert raster layer to v ector
U tilize o f IN TERSECT, SPATIAL JO IN and D ISSO LV E functions
M unicipality zonas vulnerability accord in h to ca tao ro v id ed b v E V M
i
Comparing resultsPopulation V u Inerab ili tr (PVr)
L
I
Figure 5. The fram ew ork of the hybrid ANP-ANN model.
3.4. A n a ly tic N e tw o rk P rocess (A N P ) A p p ro a ch
A n a ly tic a l N e tw o r k P ro c e s s (A N P ) [1 1 3 ] is a m o re g e n e r a l fo rm a n d e x te n s io n o f
th e A n a ly tic a l H ie r a rc h y P ro c e s r (A H P ) d e v e lo p e d b y [114- 1 1 7 ] . A N P re p re sen ts h ie ra rch ica l re la tio n sh ip s, w h e re a s A H P is b a se d o n a h ie ra rch ica l stru ctu re. In p ra ctice , n u m e ro u s d e c is io n issu es are h ard to fo rm in to a h iera rch ica l stru ctu re, as th e y in clu d e in te ractio n d ep en d e n ce w ith a b o tto m -u p approach. A N P w as rp p lied to h an d le d ep en d en ce am o n g criteria and altern ativ es w ith o u t assu m in g th at
n e tw o rk s. It a lso a cce n tu a tes in te r-d e p e n d e n t re la tio n sh ip s a m o n g d iffe re n t crite ria fo r d ecisio n s [119] . T h e A N P a n a ly sis ca n b e re p re sen ted in fo u r ste p s (A to D ), an d is d e scrib e d in th e n e x t sectio n .
3.4 .1 . S te p A : A N P M o d e l C o n s tru c tio n an d P ro b le m S tru c tu rin g
A p ro b le m s h o u ld b e w e ll p re s e n te d a n d d iv id e d in to a s e t n e tw o r k o f lo g ic a l s y s te m s . C o n s e q u e n tly , a fr a m e w o r k th a t re p re s e n ts th e n e tw o r k c a n b e s p e c ifie d a c c o r d in g to th e d e c is io n m a k e r 's o p in io n u s in g a p p ro p ria te m e th o d s.
3.4 .2 . S te p B : P a ire d C o m p a ris o n s
In A N P , lik e A H P , th e p ro b le m is d e fin e d in te rm s o f c lu ste rs a n d d e c is io n e le m e n ts w ith in th e m
a t m u ltip le le v e ls o f a b stra ctio n . F o r e x a m p le , in th is stud y, th e firs t c lu s te r is th e g o a l (e .g ., cre a tin g v u ln e ra b ility in d e x ), a n d th e seco n d is th e d im e n s io n s o r crite ria (w ith e le m e n ts o f so cia l, e co n o m ic, e n v iro n m e n ta l a n d p h y s ica l). T h e th ird c lu s te r is th e in d ica to rs (c o n ta in in g th e tw e n ty sele cte d in d icato rs). A co m p a riso n am o n g th e p airs o f d ecisio n e le m e n ts in each clu ste r is m a d e w ith re sp ect to th e ir s ig n ifica n ce fo r th e co n tro l crite rio n . A ls o , in te r-d e p e n d e n c ie s a m o n g c lu s te r in d ica to rs a re a lso
in s p e cte d p a ir-w ise . H e n ce , a s [115] s u g g e s te d , e ig e n v e c to rs c a n re p re s e n t th e m e a su re o f e le m e n ts ' in flu e n ces on e a ch o th er; relativ e s ig n ifica n ce is m e a su re d o n a sca le o f 1 to 9, w h e re th e fo rm e r b o u n d re p re sen ts e q u a l sig n ifica n ce a n d th e la tte r sh o w s e x tre m e s ig n ifica n ce . T h is m e a s u re is b a se d o n o n e in d ica to r, a ro w c o m p o n e n t in th e m a trix , o v e r th e oth er, a c o lu m n c o m p o n e n t in th e m a trix [115] .
A m u tu a l v a lu e w a s se t fo r th e p u rp o se o f re v e rse co m p a riso n , illu stra tin g th e s ig n ifica n ce o f th e (ith ) e le m e n t as a sso cia te d w ith th e (jth ) e le m e n t. S im ila r to A H P, th e p a ir-w is e c o m p a ris o n v a lu e s are a ss ig n e d in th e c o m p a riso n m a trix , an d a lo ca l p rio rity v e c to r w a s g a in e d fro m th e e ig e n v e cto r, co m p u te d w ith th e fo llo w in g fo rm u la:
A W = A m axW (2)
M a tr ix A is a p a ir-w is e c o m p a r is o n m a tr ix w h o s e la r g e s t e ig e n v a lu e is d e n o te d as A m ax.
W d e m o n s tra te s th e e ig e n v e cto r. E ig e n v e c to r X o f a c o n s is te n c y m a tr ix A ca n b e d e te rm in e d u sin g :
(A — A m a x I )X = 0 (3)
T h e Am a x v a lu e is an im p o rta n t v a lid a tio n p a ra m e te r in A N P . T h is m e a su re serv e s as a referen ce in d e x fo r e v a lu a tin g e stim a te d v e c to r u s in g th e in fo rm a tio n b y fin d in g th e C o n s is te n c y R a tio ( C R ) .
C I = (A m ax — n) (4)
n — 1
C o n s is te n c y in d e x ( C I ) is u s e d as a m e a s u re o f p a ir-w is e m a tr ix co n siste n cy . A c c e p te d V alu e o f
co n siste n cy , ( C R ) , m u s t b e less th a n 0.1.
C R = C I (5)
F o r sim ila r o rd er recip ro cal m a trice s o f an y ra n d o m e n tries, R I rep re sen ts th e av erag e co n siste n cy
in d e x . T h e e s tim a te is a c c e p ta b le if C R < 0 .1 ; if n o t, u n til th is ra n g e o f th is m e a s u re is n o t a c h ie v e d , a n e w co m p a riso n m a trix is s o u g h t rep eated ly.
3.4 .3 . S te p C : S u p e r M a trix C a lc u la tio n
C i* • • • C\„ €k\ • ■ • ekmn • • ■ tn 1 * * • Cnmm
wy* ••• W,„
w kk . . . w kn
W n k ■■■ W nn .
Figure 6. The super matrix consisting of N clusters.
w h e re , C k re p re s e n ts k th c lu s te r ( k = 1 ,2 . . . n ) w h e re th e n u m b e r o f ite m s in e a c h kth c lu s te r
is m k . T h e s e ite m s a re d e n o te d a s ek 1 , e k 2 . . . e k m k . Id e n tic a l p a ir-w is e c o m p a ris o n s a re u s e d to fin d th e p rio rity v ecto r, w h ere e a ch co lu m n is th e p rio rity v e cto r d en o ted as ( W j) . It in d ica te s th e e le m e n ts' sig n ific a n c e in ith c lu s te r w ith re s p e ct to an e le m e n t in c lu s te r ,’ [1 2 0-1 2 2] .
3.4 .4 . S te p D : S e le ctio n
T h e s e ste p g o a ls a re u s e d to a s s e s s e a c h in d ic a to r in o r d e r to c h o o s e th e m o s t s u ita b le o n e fo r
final d ecisio n m ak in g . T h e sele ctio n crite rio n is th e w e ig h ts o f altern ativ e s w h ich can b e o b tain ed from th e sy n th e s iz e d s u p e r m atrix .
3.5. A rtific ia l N eu ra l N e tw o rk
The: A rtificia l N e u ra l N e tw o rk (A N N ), a c o m p u ta tio n a l m o d e l, h a s th e a b ility to co n c lu d e n o n -lin e a r asso ciatio n s am o n g v a ria b le s in in p u t and o u tp u t d atasets. It is fo u n d ed o n a lea rn in g ro u te (training; calib ration) and is able to p ro vid e estim ated v alu es o f ou tp u t v ariab les for in p u t d ata [123,124] .
T h e s im p le s t c o n c e p tu a l d e fin itio n o f a n a rtificia l n e u ra l n o tw o rk is et m o d e l w h o s e o u tp u t is so m e lin e a r o r n o n -lin e a r co m b in a tio n o f th e in p u ts [1 2 4 ] , T h e m a th e m a tic a l in te rp re ta tio n o f A N N in w e ll e x p la in e d b y m a n y re a e a rch e rs [113, 1 2 5 ] . in b r ie f, A N N e o n s is ts o f la y e rs o f a n u m b e r o f n e u ro n s o r n o d e s th a t tra n s fo rm in p u t d a la in to o u tp u t. T h e m o s t p o p u la r ty p e o f A N N is th e m u ltila y e r
P e rc e p tro n (M L P ) n e tw o rk . A n M L P is m a d e u p o f th re e la y e rs , in c lu d in a in p u t, h id d e n a n d o u tp u t la y ers, en d th e area b e tw e e n th e m [1 2 4 ]. F ig u re 7 sh o w s th e a rch ite ctu re o f M L P u se d in th is an aly sis. D a ta fro m d iffe re n t s o u rce s, s u ch as th e m a tie so u rce s, fe e d in to th e in p u t ta y e r in w h ic h th e n e u ro n s
e x ist. T h e n e u ro n s re ly o n th e q u a n tity o f in p u t d a ta so u reesi T h is in p u t d a ta is v ig o ro u s ly p ro cesse d in th e h id d e n la y e rs , a n d in itia l o u tp u t la y e rs a n d so o n . T rial a n d o rro r d e te rm in e s w h a t w ill b e t h e n u m b e s o f h id d e n la y ers an d h o w m a n y n e u ro n s e t c h w ill h a v e [125- 1 2 9 ] . A n u m b e r o f o u tp u t lay er n eu ro n a is d eterm in e d b y tha a p p licatio n and sh o w n b y th e ty p e o f class an aly sis. E a ch h id d e n n eu ro n
in te ra cts w ith th e w e ig h te d in p u ts, w h ic h it g a m e d fro m th e e a rlter in p u t la y e rs ' lin k e d n e u ro n s [129]. A fte t d eterm in in g she w eig h te d su m o f inpuhs to each e id d e n n e u re n , a tran sfer fu n ction is u sed to find th e in itia tio n a t th e c u rre n t n e u ro n . F ig u re 6 illu stra tea th e s ig n a l flo w fso m in p u ts i.e., x 1 . . . x n an d u n id irectia n a l n atu re, as sh o w n b y arrow s. S im iitrly , o u tp u t sig n al flow? (0) o f th e n e u ro n is also sh o w n
w ith th e flo w d irectio n . T h e n e u ro o o u tp u t sig n a l 0 is o tv en b y th e fo lto w in g relatio n sh ip :
w h e re , Wj is th e w e ig h t v e cto r an d th e fu n ctio n f (net) is refe rre d to as an a ctiv a tio n (tran sfer) fu n ction .
T h e v a r ia b le n et is d efin e d as a sc a la r n et p ro d u c t o f th e w e ig h t an d in p u t v e c to rs ,
n e t = w Tx = vo1x 1 + . . . + w n x n (7)
w h e re , T is th e tra n sp o s e o f a m a trix , a n d , in th e s im p le s t ca se , th e o u tp u t v a lu e 0 is co m p u te d as:
0 = / ( n r t ) = { 1 i f
1 0 o th e r w is e
w h e re , 0 is ca lle d th e th re sh o ld lev el; an d th is ty p e o f n o d e is c a lle d a lin e a r th re sh o ld u n it [1 2 9 ] .
Figure 7. The architecture of ANN as a mufti-layered Perceptron (MLP) uoed in this study.
4. R esults
4.1. A p p ly in g A N P f o r T rain in g S ite
F ig u re 8 p reso n ts th e e sta b lish e d n e tw o rk w h e re line firs t c lu s te r d e p icts th e o v e ra ll o b je ctiv e o f th e stu d y th a t is th e so cia l, e c o n o m ic e n v iro n m e n ta l, ante p h y s ic a l v u ln e ra b ility in d e x cre atio n . T h e seco n d c lu s te r e le m e n ts are (h e fo u r m a jo r d im e n s io n s o f v u ln era b ility . T h e th ird le v e l clu ste rs are th e p rim a ry in d ica to rs o f th e fo u r d im e n s io n s o f v u ln era b ility . A fteh a n e tw o rk is e sta h lish e d ,
In d icato rs o f V u ln erab ility
w h ere , th e v e cto r W2 1 sh o w s th e e ffe ct o f g o al on V d im en sio n s. T h e m a trix , W3 2 d en o tes th e in flu en ce
of d im en sio n s o f v u ln e ra b ility o n th e in d ica to rs o f v u ln erab ility , and th e m a trix W3 3 sig n ifie s th e in n er d ep en d e n ce (in te rd e p e n d e n ce ) b e tw e e n th e V in d icato rs. T h e m e th o d o f ca lcu la tin g the co rresp o n d in g lo c a l p r io r ity v e c to r o r [W2 1 ] is illu s tra te d in T ab le 4 . T h e in d ic a to rs s e le c te d fo r th e s tu d y a re g iv e n b y th e lim it s u p e r m a tr ix th a t p ro v id e s a m e a n in g fu l in flu e n tia l w e ig h t fo r e a c h o f th e 2 0 in d ic a to rs ,
in clu d in g s o cia l, e co n o m ic, n a tu ra l, and p h y sica l. T h e se w e ig h ts , or W ANPj, are th e e le m e n ts in su p e r m a trix th a t b e lo n g to th e g o a l co lu m n . T h e s e e le m e n ts w e re n o rm a liz e d an d are s h o w n in T ab le 5 .
Table 4. The pair-wise com parison betw een various dim ensions of vulnerability.
Criteria Environmental Physical Social Economic [W21]
Environmental 1 0.89 1.38 1.15 0.24
Physical 1 . 1 1 1 1.55 1.29 0.61
Social 0.72 0.64 1 0.83 0.08
Economic 0 . 8 6 0.77 1.19 1 0.07
Table 5. The relative im portance of vulnerability indicators.
Vulnerability Dimension Indicators Ideal Normalized
PD 0.496 0.0511
Social HHD 0.337 0.0347
LPD 0.088 0.0091
EMD 0.373 0.0384
Economic UEPD 0 . 1 2 0 0.0124
CBD 0.040 0.0042
DRN 0.443 0.0456
DDC 0.494 0.0509
DRC 0.380 0.0392
DOS 0.494 0.0509
RD 0.842 0.0867
Physical BD 0.710 0.0731
ABD 0.368 0.0379
BMD QBD 0.781 0.0804
SBBD 0.295 0.0304
B 0.390 0.0402
BFD 0.661 0.0681
DF 1 0.1029
Environmental FG 0.797 0.0821
Figure 8. The ANP model for constructing vulnerability index.
4.2. C a lcu la tin g V u ln erab ility In d e x S core f o r T rain in g S ite
T h e re a re tw o sets o f d a ta , n a m e ly th e " t r a in in g sett" a n d " t e s t s e t " , w h ic h a re n e c e s s a r y to p e rfo rm A N N a n a ly s e s . "The " t r a in in g s e t " is u tiliz e d b y th e le a r n in g a lg o rith m to c re a te a s u ita b le s e t o f n e tw o r k w e id h ts , p re c is e ly illu s tr a tin g th e lin k s b e tw e e n in p u t a n d o u tp u t. Its p e rfo rm d n ce
is th e n v e rifie d o n ohe " t e s t s e t " o f d a ta w ith r e c o g n iz e d re s u lts , s o m e th in g rio t p re s e n te d b e fo re to th e n e tw o rk . P re p a rin g s u ita b le d a ta fo r th e tr a in in g site p la y s a n im p o r ta n t noie in th e a c c u ra c y o f th e o b ta in e d v u ln e r a b ility m a p . A ctu a lly , th e firs t ste p o f n e u ra l n e tw o r k r ' tr a in in g c o n s is ts o f co llu ctio n , a n a ly r is , s e le c tio n , a n d p r e -p r o c e s s ir g o f th e tr a in in g d a ta . To e ffe c tiv e ly a c h ie v e th is
o b je ctiv e , s u ita b le p a ra m e te r se le c tio n s h o u ld b e d o n e in th e tra in in g p h ase .
D u e to th e n o n -a v a iltb ility o f e a rth q u a k e re co rd s fro m 1 7 8 0 a n d la c k o f e n o u g h sam p len g an d d atab ases at sites, th e p ro p o se d m e th o d in th is research e m p lo y s a n e w tra in in g strategy. A s e xp lain ed in rhe p re v io u s te c lio n , tire p u rp o s e o f a p p ly in g th e A N P m o d e l in Shis s tu d y is to oreate a su ita b le
and w ere su b seq u e n tly u sed during; th e train in g p h ase o f the feed fo rw ard M u ltila y er P ercep tro n (M LP)
m o d el, and also to m easu re th e accu racy o f th e train ed n etw o rk . A fter b ein g sta n d ard ized , the obtained tra in in g m a p , a lo n g w ith 2 0 la y ers m a p s , are tra n sfe rre d to ID R IS I so ftw a re as th e in p u t a n d o f n e u ra l n e tw o rk a fter co n v e rtin g th e fo rm at.
46°5'30"E 46°12'0"E 46<>18,3 0 "E 46°25'0"K
45°59'0"E 46°5'30"E 4 6 °I2 '0 "E 46°I8,3 0 "E 46°25,0 "E
Figure 9. Training site map extracted from ANP model.
4.3. A p p ly in g M u lti-L a y e r P ercep tron (M L P ) N e tw o rk f o r E a rth q u a k e V u ln erab ility M a p (E V M )
M L P c la ssifie s th e re m o te ly -s e n se d im a g e r y u s in g th e b a c k p ro p a g a tio n (B P ) a lg o rith m . T h e calcu la tio n is b a se d o n in fo rm a tio n fro m tra in in g delta. M L P p e rfo rm s a n o n -p y ram etric reg ression analy sis b etw een in p u t v ariab les and one d ep en d en t v ariab le, w h ich is rep resented b y one o u tp u t neu ro n
in th e n e tw o rk [1 3 0 ] .
To m o d e l fh e u r b a n v u ln e ra b ility to e a rth q u a k e h a z a rd in T ab riz C ity, th e M L P w a s ru n in h a rd c la ss ific a tio n m o d e (th re sh o ld tra n sfe r fu n c tio n fo r o u tp u t n e u ro n s ), u s in g ID R IS I S e lv a so ftw a re (V ersion 17.1) (C lark L ab s, C lark U n iv ersity 950 M a in St., W orcester, M A , U SA ). A cco rd in g t c tine research
g o a l, w e u se d c la ss ific a tio n o p tio n fo r th e o u tp u t. T h e 2 0 in p u t la y e rs w e re th e n sp e cifie d a n d th e ir n a m e s enteoed in tire g rid . T h e m a s k im a g e co n ta in s B o o le a n v a lu e s c o n ta in in g 1s in a ll ce lls a n d 0s e lsew h ere. F o r tra in in g d ata, th e r rs te r file co n ta in in g the1 w e ig h ts o f tine selected (14 in d icato rs) -values w ere tn te re d . T h e train in g p ro cess red u ces the error b etw ee n A N N ou tp u t and the real d ata b y ad ju sting
th e w e ig h ts a c c o rd in g to th e B P a lg o rith m [131]. F o r e a c h cla ss in th e tra in in g d a ta , th e n u m b e r o f training1 a n d te stin g sa m p le sizes are ra n d o m ly d iv id e d . T h e a ctu a l n u m b e r o f p ix e ls u se d fo r tra in in g a n d testing; is a lso d e te rm in e d b y th e tatk r b e tw e e n th e n u m b e rs s p e d fie d fo r th e m a x im u m tra in in g
