Inter
DISPLAYING EARTHQUAKE DAMAGE AN URBAN AREA USING A VEGETATION-
colla
IMPERVIOUS-SOIL MODEL AND REMOTELY SENSED DATA cause
(http
for e:
Sinasi Kaya^*, Gary Llewellyn®, Paul J. Curran"
1
"ITU Civil Engineering Faculty, Geodesy and Photogrammetry Department 34469, Maslak-Istanbul, Turkey — skaya@ins.itu.edu.tr 2
"School of Geography, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom — 3
gml195@soton.ac.uk, p.curran)@soton.ac.uk
4
Commission VII, WG VII/S 5
KEY WORDS: SPOT HRV data, earthquake, land cover, Vegetation-Impervious-Soil model, Adapazari, classification
ABSTRACT:
The aim of this study was to use remotely sensed data to record earthquake-induced land cover change. On 17 August 1999, an
at 3:01:17 a.m. local time and lasted about 40 seconds. The most heavily damaged area was
The towns of Golcuk and Yalova, along the southern shore of the Gulf, the
earthquake struck northwestern Turkey,
around the Gulf of Izmit and the city of Adapazari.
harbour city of Izmit at the eastern end of the Gulf, the town of Sapanca about 40 km east of Izmit an
east of Izmit were sites of massive structural damage and extensive ground failure. The pre-earthquake and post-earthquake SPOT
cally corrected and classified and revealed that 7.1 % of the post-earthquake
relative magnitude of earthquake-induced land cover change were displayed
HRV images of the city of Adapazari were geometri
area comprised collapsed buildings. The trend and
using the Vegetation, Impervious, Soil (V-I-S) model.
1. INTRODUCTION
The North Anatolian Fault Zone (NAFZ) is one of the most
important active strike-slip faults in the world and the: most
ve fault in Turkey. During the last century, many
curred on or around this fault,
resulting in the collapse of approximately 450 000 buildings
and the death of over 80 000 people. Last century 25
catastrophic ^ earthquakes (moment magnitude, Mw > 6.5)
occurred and seven originated in northwestern Turkey (Barka
and Nalbant, 1998). For example, between 1939 and 1967, six
- large fault ruptures formed a westward-migrating sequence of
events along a 900-km long near-continuous portion of the
NAFZ (Barka, 1996) and most of the earthquakes in the
Marmara Sea region occurred on the northern strand of the
NAFZ (Ambraseys and Finkel, 1991; Barka, 1991; Barka,
1992).
important acti
catastrophic earthquakes oc
The 17 August 1999 Kocacli (Izmit) earthquake (Mw 7.4)
occurred on the NAFZ in the northwestern part of Turkey and
caused heavy damage in this density populated and
industrialized region. Cities particularly affected were Kocaeli,
Adapazari, Yalova, Golcuk, Istanbul, Bolu, Bursa and Eskisehir
and these were all on or within 10 km of the NAFZ. The
earthquake's epicentre was located at latitude 41.8° and
longitude 29.9° (near Golcuk) at a depth of around 10 to 16 km.
The most heavily damaged area was around the Gulf of Izmit
and the city of Adapazari. The dead and injured totalled
approximately 15,851 and 43,953 respectively in city centres
(Sahin and Tari, 2000) and approximately 18,000 and 48,000
respectively in greater urban areas (Barka, 1999). The
distribution of those who died in city centres was: Golcuk
(5,025), Izmit (also known as Kocaeli) (4,093), Adapazari (also
known as Sakarya) (2,629), Yalova (2,502), Istanbul (981),
Bolu (264), Bursa (268), Eskisehir (86), Zonguldak (3) (Sahin
ue ee
* Corresponding author.
d the city of Adapazari 50 km
and Tari, 2000). By way of illustration, Adapazari was 50 km
from the earthquake epicenter and 3,891 people died in its
greater urban area (www.sakarya.gov.tr, 2003).
. Remotely sensed data have been used to record land cover
change in general (Welch and Ehlers, 1987; Pathan et al., 1993;
Kaya, 1996; Foody and Boyd, 1999; Yang, 2002, Kaya and
Curran, 2003) and earthquake-induced land cover change in
particular (Yonezawa and Takeuchi, 2001, Turker and San,
2003). The aims of this study were (i) to use SPOT HRV XI
data to quantify the extent of building collapse, in the
Adapazari region, as a result of the 17 August 1999 earthquake
and (ii) present the land cover change trend in the study area by
means of the Vegetation- Impervious- Soil (V-I-S) model.
2. METHODOLOGY
2.1 The Study Area on 17 August 1999
The earthquake started in the west, lasted for 12 seconds,
paused for approximately 18 seconds and was followed by
rupture in the east for 7 seconds (Barka, 1999). The maximum
offset along the surface break was measured near Arifiye, east
of Sapanca (between Arifiye and Adapazari) (figure 1). The
fault displaced a road horizontally by about 5 m and a railway
horizontally by about 2.7 m and also vertically by about 1 m.
Adapazari suffered more damage as a result of building collapse
than Izmit and Yalova (figure 2, table 1), as more of buildings
were constructed on readily-liquefied sediments (Scawthorn,
1999; (Erken, 1999). During the earthquake, two buildings on
pile foundations and 1-2 story buildings were largely unaffected
but 3-6 story buildings, typically on shallow mat foundations,
displayed a substantial amount of base settlement, rotation and
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