Development of Disaster Information Management Systems
in Asia by Using Internet GIS

Bambang Rudyanto*, Hirotaka Suzuki**, Yujiro Ogawa*, Atsushi Takeda***, Shigeya Yoshikawa****

* Asian Disaster Reduction Center, IHD 3F, 1-5-1 Wakihamakaigan Dori, Chuo-ku, Kobe-shi 651-0073, Japan
** Osaka City University, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka 558, Japan
*** Tohoku Bunka Gakuen University, 6-45-16 Kunimi, Aoba, Sendai 981-8551, Japan
**** Asian Air Survey Co., Ltd., Aoki Daisan Building 2F, 7-3 Tamura-cho, Atsugi-shi, Kanagawa 243-0016, Japan

Abstract

It is hard to use disaster information from the satellite image for actual disaster management without overlaying it to general geographical data such as topography and natural condition, and social situation including Geographic Information System (GIS) application has disturbed utilization of disaster information via GIS. To solve the problems, we have developed VENTEN (Vehicle through Electric Network of disasTer gEographical informatioN ) which is available to anyone. Background of VENTEN development, VENTEN system and data to be processed by VENTEN are discussed, and the possibility of utilizing VENTEN for disaster management is analyzed in this paper.

Keywords: VENTEN; Internet GIS; Disaster Information Management System

1. Introduction

The improved reliability of disaster information from satellite image data due to recent advanced image processing technology enables us to obtain various disaster information via remote sensing at anytime and anyplace, improving the ability to utilize it for disaster mitigation. Until this time, however, a system immediately contributing to disaster management for disaster mitigation has not often been discussed. That is because much attention has been paid to technological breakthrough by satellite image data providers, and those who are working in disaster management have not been actively involved in this field. Also, it is hard to use disaster information from a satellite image for actual disaster management without overlaying it on general geographical data such as topography, and population, buildings and infrastructure. Furthermore, the high cost and skills required for the application of Geographic Information System (GIS) technology has hindered its utilization for disaster information. Disaster management is required to deal with incidents in the real world. In this regard, GIS, which can process two-dimensional as well as three-dimensional data, has large potential for utilization in emergency situations at the time of disasters, and can be used for evacuation planning as well as incorporating satellite information. Nevertheless, GIS has not yet been widely used for the reasons mentioned above.

To solve the problems, we have developed VENTEN (Vehicle through Electric Network of disasTer gEographical informatioN), which is available to anyone. In this paper, the background of VENTEN development is explored, VENTEN system and data to be processed by VENTEN are discussed, and the possibility of utilizing VENTEN for disaster management is analyzed.

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2. Background

2.1 Disaster in the Asian Region

The Asian region, with a number of earthquake epicenters, volcanoes and large-scale international rivers, and in the path of typhoons, is prone to natural disasters. Furthermore, once a disaster occurs, human and property damage can expand in the many megacities vulnerable to disasters. The patterns of disasters in the Asian region, which will be processed by VENTEN, are analyzed by using the Emergency Events Database (EM-DAT) administrated by Center for Research on the Epidemiology of Disasters, Universite Catholique de Louvain (UCL).

Fig.1 shows the amount of disaster occurrence by region. As damage caused by disasters varies year by year, the number of cases counted every ten years is recalculated into a yearly average value for the vertical axis. As shown in Fig. 1, disaster occurrence in the Asian region always accounts for approximately 40-50% of the total in the world, which seems to be remarkably high considering the land area of this Asian region is approximately 20% of the total in the world. It suggests that disaster countermeasures are given higher priority in the Asian region than in other regions. Since the death toll and the amount of damage are not analyzed in this figure, the effect of disasters that caused extensive damage is not taken into consideration.

Fig. 2 shows the death toll by region and by disaster type. The death toll in the Asian region is much higher than in other regions. The number killed in the 48 years from 1950 to 1998 in Asia is 4,938,045 in total, which is more than 70% of the total number killed in all regions combined. In comparison with the population of the Asian region of approximately 58% to the world population, the death toll in Asia is very high. Regarding the type of disasters, drought is the main cause of damage both in the Asian and African regions. In addition, floods, earthquakes, and typhoons result in the increase of the death toll in the Asian region. In particular, the number of dead caused by floods reached 45% of the total death toll in Asia, characterizing the damage in this region. Many large rivers are located in this region, including the Yangtze, Ganges and Brahmaputra rivers. Most of them run through the area with a great deal of precipitation, resulting in more extensive flood damage than other disaster damages.

Wide areas are damaged by floods, frequently resulting in international problems. As floods also gradually damage the area for a long period of time, satellite image data will be useful for grasping the extent of damage and for disaster prevention planning to mitigate future damage. Taking all these factors into consideration, in order to reduce damage caused by a disaster, it is significant to introduce GIS to all in this field.

2.2 Awareness of Administrators of Disaster Management in Asia

Asian Disaster Reduction Center (ADRC) held the first ADRC Expert Meeting on February 17-18, 1999, with the participation of administrative officials in charge of disaster management in Asian countries discussing how to preserve the lessons we learned from past disasters for our children and grandchildren. The meeting had four workshops. The one titled "Utilization of technology" discussed utilization of remote sensing and GIS for disaster management and produced the following conclusions at the meeting after an active discussion.

* All the participating countries are aware of the value of GIS and remote sensing, and the advantages of their utilization for disaster information management.
* The Future challenge is to give technological support for getting satellite images in real time and at a cheaper price, to introduce GIS and remote sensing, and to acquire the skills required for understanding abstract information for disaster management.

As mentioned above, the administrative office of disaster management of each country is highly interested in GIS and remote sensing, but the cost for introducing these and the required high skills needed prevent them from introducing these technologies. The high price for satellite image data and geographical data is also a reason. Despite the high interest in GIS and remote sensing, various problems hamper them in introducing these technologies. All this indicates that those concerned truly want these problems to be solved.

2.3 The Current Situation for Internet Access to Disaster Information in the Asian Region

It is desirable to develop a unified system, which enables users to access information via the Internet, considering the cost and data to be delivered. However, the infrastructure for the network varies from country to country, and despite good infrastructure it is not always available for other reasons. After establishing that the users in the Asian region--the main users for this system--use the Internet to get disaster information, Internet GIS is highly likely to be used, taking into consideration the further improvement of the network environment.

Other than VENTEN, ADRC has provided disaster information of mainly text and numerical data both in Japanese and English, on the World Wide Web via the Internet since August 1998. This section discusses access log-in to the disaster information service and the current state of using the Internet for disaster information.

Between August 1st in 1999 and March 31st in 2000, disaster information service (both Japanese and English service together) was accessed 42,506 times. Among those, 28,294 were from Japan (from a host with a "jp" domain name), suggesting that the location of ADRC and service in Japanese have contributed to that number. Table 1 shows the analysis of access to the service by domain name, including access from Japan.

ADRC Member Countries 15
ADRC Advisory Countries 4
Non ADRC Member Countries in Asia 8
Domain with other Countries 30
Others 6
Total 63

Although it suggests that most access to the service is from Japan, the service is accessed from wide area of the Asian region. Obviously, the service has been accessed most from the Asian countries because it mainly provides disaster information for the Asian region. Considering the number of access hits from Western countries, where network infrastructure is well advanced and information provided in English, information service via the Internet is very much needed by Asian countries. In this regard, with the network infrastructure to be improved, the Internet has great potential for users to obtain geographical disaster information in the Asian region.

2.4 VENTEN Development Policy

Against the background mentioned above, ADRC has developed a disaster information management system available to anyone from anywhere using the Internet, the progress of which has been remarkable.

The objective of VENTEN development is to provide the system and data. The system is available to any user via the Internet only if they prepare a PC connected to the Internet and has a Web browser. Although various international institutions provide basic geographical information including topography and other natural conditions, it has been difficult to obtain and hard to use because the data format should be changed according to the GIS application to be used. In developing VENTEN, ADRC has changed the format of gathered geographical data so that it can be used on the VENTEN system, and provides the data as a part of the system.

Fig. 3 shows the positioning of VENTEN. On the left of fig. 3, information providers, including various space science institutions and aerial photograph organizations, give the original primary data. Various image data processing and overlaying of data are necessary to obtain useful information for disaster management from the primary data. A pipeline is required to provide the processed information to those in charge of disaster management. Researchers in the disaster management can study and analyze information on VENTEN and add their results to it. VENTEN functions as a database, analyzes geographical disaster information, and serves as an information distribution channel to those in charge of disaster management. In other words, VENTEN enables geographical disaster information to be fully utilized for disaster management, including planning and relief activities at the time of disaster.

3. VENTEN system

3.1 The Information-Processing Flow of VENTEN

The VENTEN system consists of a Web server, GIS server and database server. Fig. 4 shows the information-processing flow in VENTEN. Upon requests from users, the Web server specifies the necessary information, including what geographical data and what area are needed (more than one geographical data selection is possible), for the GIS server. The GIS server refers as necessary to the database server and extracts the necessary area from geographical data in memory, and then processes it to send to a Web server in a form of raster image data. The Web server adds a country selection menu, geographical disaster information selection menu, a show/hide selection button for basic geographical data, and a button for changing the scale of the area displayed (other than geographical data). Then it sends users information in hypertext format with the raster image data provided by the GIS server.

There are a couple of systems for Internet-based GIS. For example, downloading an application program can use one of them. Another system based on an image map only provides geographical information. VENTEN can be positioned in-between those two systems. In other words, users can process vector data on VENTEN, but obtain only raster databased on the vector data. Although it restricts users to obtaining data, this system solves the problems of differences in response caused by different network environments, the performance of the client's machine at the time of operation, and of the property rights for data. For Internet GIS, the traffic load on the network when sending data is problematic. However, since VENTEN only sends a fixed scale of image of 470 x 470 pixels to be displayed at the center of the VENTEN screen, it takes the server longer in calculation. The difference in network environments between VENTEN and end users do not have significant impact in data sending. Most data processing is done by the server machine and all the client machine should do is to display data it receives, so that differences in performance of client machines does not have significant impact. It is easy to persuade many data providers to join in this system because vector data, which is very close to the original information in its amount, is not given to users. The users will finally get only raster data, but users can process it the same as vector data.

3.2 The Platform and Device for VENTEN

In the current VENTEN system, the Web server, GIS server and DB server shown in fig. 4 are located in the same machine, but those will be separated one by one in the future as both the data to be processed and the access load increase. Processing is controlled by a Microsoft Windows NT server. MICROSOFT IIS (Internet Information Server) controls the Web server. Databases, which are made by Oracle8, are accessible via Microsoft ODBC. For the GIS server engine, ASC (Active Server Component) of Informatix's SIS (Spatial Information System) is used. User requests are sent to the GIS server in a script embedded in an html document managed by the Web server. The GIS Server creates new image data upon the request and returns it to the Web server. Then the image data with peripheral menus and related information added by the Web server is sent to the users.

3.3 How to Operate VENTEN

Fig. 5 shows the initial screen of VENTEN. VENTEN consists of a map at the center, four menus and a display window, and an additional window created when necessary. The map in the center shows the ADRC member countries. The country to be displayed can be selected here. The country selection menu on the upper left of the screen also can be used to select a country. On the lower left is a control menu for the map scale, area to be displayed, and buffering. On the upper right is a geographical disaster information selection menu. The information to be displayed can be specified by country name and disaster type.

When you specify a country name or geographical disaster information on the initial screen of VENTEN, the contents of the window change. As shown in fig. 6 and 7, the same lower left and upper right windows are displayed, but on the upper left is the property of the selected object, and in the lower right window is the show/hide toggle for the basic geographical information of the map shown in the center. This window can be used to not only select show/hide of the information, but also to set items to be selected/deselected as an object. This operation enables users to easily select an object by clicking on the map, which sometimes becomes a complicated process.

3.4 VENTEN fFunctions

VENTEN has GIS standard functions of "drawing map in any scale," "buffering," "overlaying" and "searching by location and attribute." Fig. 6 shows a buffer with the results of city populations in the buffer. The buffer is set to 30 km with Osaka Itami Airport as its center. The city names and their populations in that area are shown in another window. Likewise, VENTEN provides raster-based information to the end users, but the users can make various requests to process vector data on the server, enabling VENTEN to provide a service more advanced than that of Internet-based GIS with browsing as its main function.

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4. Data to Be Covered by VENTEN

VENTEN covers data gathered from 22 ADRC member countries. ADRC has gathered two different data: general and basic geographical information to be used but not limited to disaster management, and geographical disaster information upon which the disaster management related information is reflected. So far the following data has been gathered:

Basic geographical information
* National borders (area)
* River systems (lines and area)
* Railways (lines)
* Roads (lines)
* Airports (point)
* Cities (point)
* City names (string)
* Populations (numerical value)
* Images with shading based on land height (raster image)
* Contour maps (raster image)

Disaster geographical information
* Flood-stricken area of Yantze River in 1998
* Damage on buildings in the area of Nishinomiya Station at the time of the Great Hanshin-Awaji Earthquake in 1995

As mentioned in 3.3, the basic geographical information can be shown or hidden by the menu on the lower right of the VENTEN screen. And basic geographical information can be overlaid with geographical disaster information. Fig. 7 is the data samples, showing image data with shading based on rivers and land height of India/Bangladesh to the top, and an image with shading based on the railways/road and land height of Taiwan to the bottom.

Fig. 8 is a geographical disaster information sample, showing the flood-stricken area of the Yantze River in 1998, abstracted from a LANDSAT image overlaid with river, road and railway data from that actual time. As shown in fig. 8, VENTEN can be used to obtain the geographical disaster information overlaid with other data, making the data extremely useful for disaster management.

5. Conclusion

So far this paper has presented the development of an Internet-based geographical disaster information system, its background and system, and data covered by the system. Current VENTEN is still rudimentary, with minimum functions available to the public. It is necessary to call on the related organizations to provide data in order to increase geographical disaster data for VENTEN. For the system, we will operate it on a trial basis at the administration for disaster management, and improve the interface and extend functions based on the results. For data for VENTEN, we will call on the satellite information providers, research institutes and universities studying disaster reduction-related remote sensing to provide information. Some basic geographical data is old or doesn't fully cover the target area. ADRC tries to obtain the latest data and asks the ADRC member countries to cooperate in gathering the latest data.

Currently VENTEN can display and analyze the gathered basic geographical data and geographical disaster data, but in the future, we will connect it to disaster information services providing text and numerical data mentioned in 2.3. The disaster information service system provides two entrances: by information category and by country, for a user to easily hit his/her target information. As disaster information increases, the current directory configuration may not be sufficient. Therefore, we plan to add the geographical search function for the huge amount of disaster information to the system, by using a part of VENTEN functions to substantially improve the user interface.

The data processing mentioned in 3.1 was applied in developing the system considering the network, the load on the client machine, and the copyright for data. However, other systems like JaMaPS have already been proposed, under which client machines will process geographical data to some extent and distributed data will be referred or analyzed. The main objective of developing VENTEN is to share the lessons we have learned from past disasters in a smooth information exchange. Through technological renovation and improvement of the network infrastructure, we will use the best possible method at each time to develop this system of sharing disaster information.

Acknowledgements

This project is supported by Japan Science and Technology Corporation, Research and Development Applying Advanced Computational Science and Technology . We wish to express our gratitude for its support.

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<Figures>

Fig. 1: The number of disasters occurred by region.


Fig. 2: The death toll by region and by disaster type.


Fig. 3: The positioning of VENTEN.


Fig. 4: The information processing flow in VENTEN.


Fig. 5: The initial screen of VENTEN.

Fig. 6: Itami Airport.

Fig. 7: India/Bangladesh (upper) and Taiwan (lower).


Fig. 8: Flood-stricken area of the Yantze River