8CUEE CONFERENCE PROCEEDINGS
8th International Conference on Urban Earthquake Engineering
March 7-8, 2011, Tokyo Institute of Technology, Tokyo, Japan

BUILDING DAMAGE AND TSUNAMI INUNDATION GIS DATASETSAFTER THE 2010 CHILE EARTHQUAKE

Yoshihisa Maruyama1), Fumio Yamazaki2), Shizuko Matsuzaki3), Hiroyuki Miura4),
and Miguel Estrada5)1) Associate Professor, Department of Urban Environment Systems, Chiba University, Japan
2) Professor, Department of Urban Environment Systems, Chiba University, Japan
3) Graduate Student, Department of Urban Environment Systems, Chiba University, Japan
4) Assistant Professor, Department of Built Environment, Tokyo Institute of Technology, Japan5) Associate Professor, Japan Peru Center for Earthquake Engineering and Disaster Mitigation, National University of Engineering,Peru
ymaruyam@tu.chiba-u.ac.jp, yamazaki@tu.chiba-u.ac.jp, 10td0309@graduate.chiba-u.jp, hmiura@enveng.titech.ac.jp,
estrada@uni.edu.pe

Abstract: This paper presents the results of a field survey conducted by the authors after the 2010 Chile earthquake.
The authors visited the affected area about a month after the earthquake. The GIS datasets for the damage levels ofbuildings in Talca and the tsunami-inundated areas in Talcahuano, Dichato, and Constitución are constructed in this study,
and a series of fundamental analyses are performed using a digital elevation model (DEM). Further, the usefulness ofsatellite images captured after the earthquake to detect damaged buildings in Talca is discussed using the GIS datasets
constructed in this study.

1. INTRODUCTION
The 2010 Chile earthquake occurred off the coast of
the Maule Region of Chile on February 27, 2010, at 03:34
local time (06:34 UTC) with a magnitude of 8.8 on themoment magnitude scale. The epicenter was offshore fromthe Maule Region, approximately 335 km southwest ofSantiago, the capital of Chile, and 105 km north-northeast of
Chile’s second largest city, Concepción. It is reported that asevere ground motion with the Modified Mercalli Intensity(MMI) scale of VII was felt widely in Chile and that theextensive damage was caused by the ground shaking andtsunami (USGS, 2010). The total economic loss estimates
range from USD 15 to 30 billion, which correspond to 10%
to 15% of Chile’s real GDP (Bray and Frost 2010).
According to the report on the scene, the actual death toll
was 486 as of March 8, 2010, and approximately 370,000
homes were damaged.
The authors visited the affected area about a monthafter the event as part of an international research project“Enhancement of earthquake and tsunami disaster mitigation
technology in Peru” (Yamazaki et al. 2010), which is under
the research program “Science and Technology ResearchPartnership for Sustainable Development (SATREPS)” (JST2008) supported by the Japan Science and Technology
Agency (JST) and the Japan International Cooperation
Agency (JICA). The lessons learned from the 2010 Chile

earthquake are expected to apply to the earthquake disastermitigation technologies in Peru because the two countries
have common regional tectonics and social surroundings.
Three teams of Japanese and Peruvian researchers
were dispatched by the SATREPS project to carry out fieldsurveys. In this paper, the results of the field survey
performed by Damage Assessment Group and Disaster
Mitigation Plan Group are presented. The spatial damage
data, topographical maps, and satellite images provided bydifferent institutions are compiled by the geographicalinformation system (GIS), and the primitive analyses areconducted to reveal the characteristics of thetsunami-inundated areas in view of elevations and damage
incidents to adobe and unreinforced masonry buildings,
which are also widely seen in Peru.

2. OUTLINE OF FIELD SURVEY
The authors arrived in Santiago on April 2, 2010. We
drove to Concepcíon the next day and visited thetsunami-affected areas of Talcahuano, Dichato, andConstitución. We moved to Talca on April 7 and left
Santiago on April 8. Before leaving, we visited Valparaíso
and Viña del Mar. Figure 1 shows the locations of the cities
that we visited during the survey.
Figure 2 shows the route of our field survey in Santiago- 103 -Figure 1 Locations of cities visited by the authors
Figure 3
Survey route and field photos inConcepcíon—April 4, 2010

Figure 2
Survey route and field photos in
Santiago—April 2, 2010and some field photographs. The route was recorded by aportable GPS device during the survey and the location ofthe photo shooting could be identified as the location data
were embedded in the Exchangeable Image File Format(EXIF). An RC building with 20 stories constructed in 2003
suffered from shear failures in columns and walls at the firstand the second stories. A collapsed highway bridge and anFigure 4
Survey route and field photos inDichato—April 5, 2010
RC building with the collapsed first floor were found. The
locations of these sites are also shown in the survey route inFig. 2.
Figure 3 shows the survey route in Concepcíon. An RC- 104 -Figure 6 Cumulative frequencies of the areas ofbuilding lots with respect to the damage level

Figure 5 GIS file to show the damage levels ofbuildings in Talca and locations of field photos
building with the damaged middle floor was found at the site
numbered 1. An RC building with 15 stories had collapsed
completely at the site numbered 2. The road bridges
collapsed at sites 3 and 4. The temporary bridge girder wasconstructed two days after the earthquake at site 3. Although
the photos are not shown in this paper, the adobe andunreinforced masonry constructions were severely damaged
in the urban area.
Figure 4 shows the survey route in Dichato. It isreported that more than 80% of the built-up area in Dichato
suffered from tsunami (Humboldt State University
Preliminary Tsunami Survey Team, 2010). As shown in thefield photos, the buildings collapsed because of the tsunami
waves. A ship was conveyed against the river flow becauseof the tsunami and eventually found at site 3.

3.
CONSTRUCTION OF GIS FOR BUILDINGDAMAGE AND TSUNAMI-INUNDATED AREA
3.1 Building Damage GIS in Talca
Talca is the capital of both Talca Province and Maule
Region. Its population is approximately 200,000, and it isapproximately 250 km south of Santiago and 60 km
northwest of the epicenter of the 2010 Chile Earthquake.
According to USGS (2010), Talca was affected with a severe
ground motion with the MMI scale of VII.
During our survey, we interviewed officials from Maule
Regional Office to investigate the damage of buildings. As aresult of our interview, an image file that shows the damagelevels of buildings was provided. The polygons, whichindicate the building lots, are classified into four levels,
namely, to be removed, to be repaired, no damage, and underinvestigation. It should be noted that the image file wascompiled with the damage dataset as of March 31, 2010.
In this study, the location of the image file wasestablished in terms of map projections. The satellite imageand road data presented in Google Earth were employed as abase map to georeference the image file. Then, the image file
was converted to a GIS file with polygons to identify thedamage levels of buildings. Figure 5 shows the developed
GIS file presented by Google Earth and some field photos toshow the examples of damaged buildings.
In all, 5617 polygons were projected to the map
coordinate system. 1559 (27.8%), 1872 (33.3%), and 1864
(33.2%) buildings were classified as to be removed, to berepaired, and no damage, respectively. The typicalconstruction types in Talca are adobe and unreinforced
masonry buildings, which are primarily used for older
constructions with 2–4 stories (dating back to before the1960s–70s). Modern buildings that were designed according
to the current codes suffered minor, repairable damage,while a large number of adobe and unreinforced masonry
constructions suffered significant damage (MCEER, 2010).
Figure 6 shows the cumulative frequencies of the areasof building lots with respect to the damage level. The meanof all the georeferenced areas was approximately 430 m2 andwas almost equal to that of the areas associated with thebuildings to be repaired. The mean of the lot areas of thebuildings to be non-damaged was approximately 340 m2,
which was considerably smaller than that of the buildings tobe removed. On the basis of the results, it has been
speculated that the newer buildings are constructed inrelatively small lots; however, the construction periods are
not available at this moment.
Recent advancements in remote sensing technologies
and their applications have made it possible to use remotelysensed imagery for estimating the damage distribution due tonatural disasters. Among them, high-resolution opticalsatellite imagery, which has become available in the last
decade, has made satellite remote sensing more useful indisaster management since even the damage status ofindividual buildings can be identified (Saito et al. 2004,
Yamazaki et al. 2005). Figure 7 compares the pre- and- 105 -(a) Pre-event (Jan. 1, 2008)(b) Post-event (March 10, 2010)(c) GIS data
Figure 7 Comparison between pre- and post-event
satellite images to detect affected buildings
post-event high-resolution optical satellite images with theGIS dataset shown in Fig. 5. As for the pre- and post-event
images, the image captured by QuickBird on January 1,2008, which is presented in Google Earth, and that captured
by WorldView-2 on March 10, 2010, are employed in thisstudy. A comparison of the pre- and post-event images
revealed that some of the affected buildings could bevisually detected, but not all the damaged ones could beidentified appropriately. Since the post-event image wascaptured with the large off-Nadia angle (40.3°), the qualityof image is not sufficient for visual damage inspection.
Moreover, the number of affected buildings whose roofs hadcompletely collapsed is small in Talca. Hence, it can beconcluded that the damaged buildings in Talca are difficult
to be detected through visual damage inspection using
satellite images.
3.2 Development of GIS for Tsunami-Inundated Area
Various institutions released the maps to show thedamage distribution at their Web sites after the 2010 Chile
earthquake. The tsunami-inundated areas interpreted fromsatellite and aerial images were published by National Officeof Emergency of the Interior Ministry (ONEMI) of Chile

Figure 8 Tsunami-inundated areas in Talcahuano,Dichato, and Constitución(SNIT 2010). On the basis of the maps, the number ofaffected buildings and that of causalities were estimated.
In this study, the tsunami-inundated areas wereprojected onto a map coordinate system, and the
topographical conditions were evaluated in terms of theelevation. The inundated areas in Talcahuano, Dichato, andConstitución were converted to the GIS data and comparedwith the digital elevation model (DEM). The DEM
employed in this study is the ASTER Global Digital
Elevation Model (GDEM) developed by the Ministry ofEconomy, Trade, and Industry (METI) of Japan and theUnited States National Aeronautics and Space
Administration (NASA) (ERSDAC 2009). The ASTER
GDEM is a highly accurate DEM covering all the land onearth with the spatial resolution of 30 m.
Figure 8 shows the tsunami-inundated areas in
Talcahuano, Dichato, and Constitución and the distributionsof the elevation derived from the ASTER GDEM. The
elevations in the inundated areas are lower than 20 m on the- 106 -25
Talcahuano

Elevation (m)201510Line 1Line 25005001000
1500
Distance from the coastline (m)2000

25Elevation (m)2015Dichat
10Line 1Line 25005001000
1500
Distance from the coastline (m)2000

25Elevation (m)20
1510Constitucio

5Line 1
Line 2

Figure 10 Measurement of tsunami inundation depth inTalcahuano
250

0500
1000
1500
Distance from the coastline or river (m)Inundation depth (cm)02000

Figure 9 Elevations along the transverse lines set in Fig. 8150
100
Talcahuano
DichatoConstitucion

500051015202530

Elevation (m)250Inundation depth (cm)whole except for a certain area in Constitución. As shown in
the figure, we set the two traverse lines in each inundated
area. The elevations were extracted along the two lines. The
extracted elevations are illustrated in terms of the distancefrom the coastline in Fig. 9. As for Line 2 in Constitución,
the elevations are presented with respect to the distance fromthe Maule River. The relatively low elevations and slow
grades result in long travel distances of the tsunami wave.
According to Line 2 in Talcahuano, the tsunami wave could
travel approximately 2000 m from the coastline. Line 1 inConstitución was assigned to identify the surveyed site byImamura et al. (2010). According to their report, the tsunami
runup height was 28.3 m at the site. Since the DEM used inthis study is a global dataset that consists of 30-m grid cells,
the elevation at the site is estimated to be approximately 23
m. The slope is estimated to be approximately 67% and isalmost equivalent to that reported by Imamura et al. (2010),
which is 63.5%.
As shown in Fig. 10, the inundation depth wasmeasured at several sites in the three cities. The inundation
depth along the beachfront street in Talcahuano was larger
than 150 cm, but a depth of 55 cm was observed in its
bystreet (site 4). Figure 11 summarizes the measurements inthe three cities. The inundation depth is presented with

200

200
150
100
Talcahuano
50Dichato
Constitucion

00100

200

300

400

500

600

Distance from the coastline or river (m)Figure 11 Summary of the measurement of tsunami
inundation depth
respect to the elevation and the distance from the coastline.
As for the results in Constitución, the records are shownwith respect to the distance from the Maule River. A clear
tendency is not seen in the relationship between the tsunami
inundation depth and the elevation. The recorded depth in- 107 -Talcahuano and Constitución decreased with an increase in
the distance from the coastline or the river; however, thistendency is not seen from the records in Dichato because of
the insufficient number of measurements.

4. CONCLUSIONSIn this paper, the results of a field survey conducted
after the 2010 Chile earthquake by the authors during April
2–8, 2010, are presented. The GIS dataset for the buildingdamage in Talca was developed by establishing the locationof the image file in terms of map projections. The usefulnessof high-resolution satellite images to detect the building
damage in Talca was investigated with the aid of theconstructed GIS dataset. Moreover, the tsunami inundation
maps published by ONEMI were georeferenced, and thecharacteristics of the inundated areas were evaluated in viewof the elevation.
According to the relationship between the building
damage levels and the lot areas, the mean of the areas
associated with the non-damaged buildings was the smallest,
while the mean of the areas associated with the buildings tobe removed was the largest. In Talca, modern buildings thatwere designed according to the current codes suffered minor,
repairable damage, while a large number of adobe andunreinforced masonry constructions, which were built in the
1960s–70s, suffered significant damage. On the basis ofthese circumstances, it has been speculated that the newer
buildings may be constructed in relatively small lots;
however, the construction periods are not available at thismoment. According to the results of a visual damage
inspection using pre- and post-event satellite images, it wasconcluded that the damaged buildings in Talca could not beappropriately detected because of their damage patterns andthe quality of the post-event satellite image.
A comparison of the georeferenced tsunami-inundated
areas with the elevations obtained from the ASTER GDEM
revealed that the elevations in the inundated areas werelower than 20 m on the whole except for a certain area. A
clear tendency was not seen in the relationship between thetsunami inundation depth and the elevation. The recorded
inundation depth in Talcahuano and Constitución decreased
with an increase in the distance from the coastline or theriver.
These findings of our field survey after the 2010 Chileearthquake will be expanded in the earthquake and tsunami
disaster mitigation technology in Peru through theSATREPS project.

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Acknowledgements:
The authors would like to express their sincere gratitude to theJapan Science and Technology Agency (JST) for the financial
support in conducting the field survey under the SATREPS project“Enhancement of earthquake and tsunami disaster mitigation
technology in Peru” (Principal Investigator: Prof. Fumio Yamazaki,Chiba University).
References:Bray, J. and Frost, D. (2010), “Geo-engineering Reconnaissance of- 108 -