A Study of Areospace Reconnaissance of Earthquake Sites
Tsuyoshi Kondo*, Takeshi Doihara*
Osamu Uchida**, Hirokazu Muraki**
Asia Air Survey Co,.Ltd. Research Institute
* 8-10 Tamura-cho, Atsugi, KANAGAWA, 243 Japan
** 2-1-11 Esaka-cho, Suita, OSAKA, 564 Japan
This paper proposes effective utilization of image resources of earthquake sites. After the Southern Hyogo Prefectural
Earthquake, more than 10,000 aerial photographs were taken and have been effectively used for relief activities,
prevention of multi-hazard, restoration, and redevelopment planning. However, even with aerial information support,
unexpectedly tremendous time and labor have been spent after the tragic earthquake because of mobilization delay
which was caused by untimely recognition of the extent of the darnage. To solve this problem, we have surveyed
requirements of information in the disaster of the quake and have found that instant availability of information is the
most important factor right after the quake; accuracy will be required only in later stages. Aerial photographs do not
have instant availability because of wet-process, even though they can satisfy the accuracy requirement. Since high
resolution satellite imagery will become available after 1997, we used simulated images to analyze the potential for
interpretation, measurement and mapping. We have come to the conclusion that high resolution satellite imagery has
instant availability but does not have accuracy, and therefore can be complementary when used together with aerial
photographs to effectively help damage reduction and quick restoration of earthquake sites.
Introduction
In Japan where earthquakes occur frequently, it is important to collect accurate information of damage in
the early stages of quake disaster to decide proper and efficient mobilization of relief activities. Aerial
photography is one of many spatial data media which record damage situations of disaster areas. Right
after the Southern Hyogo Prefectural Earthquake in early 1995, more than 10,000 aerial photographs were
taken in five days after the quake broke out (Rikimaru, 1995). These photographs provided data for
damage recognition, mapping, and 3-D measurement (see Fig. 1). The following objects and situations
were found to be recognizable by interpreting the photographs (Doihara, 1995; Yoshizawa, 1994; Suzuki,
1995; Tsukaguchi, 1995; Toyama, 1995):
O collapsed houses (wooden,steel-frames,reinforcedconcrete)
O slope failure, landslide blocks
O falling, insulation, subside, blockade of roads and railways
O liquefaction/ sandboiling(seeFig.2)
O derailedtrains
O trafficjams
O coastatpollution
O Iineaments,faults
O collapsedharborfacilities
O collapsedtombs
O burneddownarea
O crackedshoreprotectingstructures
However, even with aerial information support, unexpectedly tremendous time and labor have been spent after the
tragic earthquake, because of delay of initial motion (Kawata, 1995). Shibazaki (1995) points out that this
delay was primarily caused by untimely recognition of damage situations in early stage.
Fig 1. Distrubution of geographical displacements in western Kobe city by means of stereoscopic measurement
Fig 2. Distributions of liquefaction among the Osaka-bay
In this paper, we discuss effective utilization of image resources for earthquake sites. First, we review
information requirements in the quake disaster, and discuss the applicability of the information of aerial
photography. Next, we evaluate the applicability of high resolution satellite imagery, which is scheduled
to be regularly available from the beginning of 1997, to aerospace reconnaissance in a disaster area by
using simulated images. Finally, we discuss complementary utilization of aerial photography and high
resolution satellite imagery to help damage reduction and quick restoration of the earthquake sites.
Requirements of Information and Reconnaissance with Aerial Photograph in the Desaster of ]
southern Hyogo Prefectural Earthquake
We have summarized the information required after the quake broke out by surveying news clips reported
by newspapers related to aerial photographs. Table. 1 shows information requirements at each stage of the
disaster and the actual reconnaissance processes with aerial photography in the disaster of the Southern
Hyogo Prefectural Earthquake.
