Download The Establishment of Earthquake Emergency Command Information System Based on GIS

The Establishment of Earthquake Emergency Command Information
System Based on GIS
ZENG Jun1,2, ZHANG De1,2
1. Surveying and Mapping Institute, Information Engineering University, P.R.China, 450052
2. Xi’an Research Institute of Surveying and Mapping, P.R.China, 710054
[email protected]
Abstract: It is a powerful guarantee to establish a full-functioned and effective earthquake emergency
command information system for the government realizing earthquake-preventing, disaster reduction,
rapid response and scientific decision-making. This paper discusses an architecture which is composed
of C/S and B/S of earthquake emergency command information system and details the main functions
and techniques of the data service layer, application service layer, web service layer and client
application layer. Based on the GIS platform, the system can integrate the disaster information, predict
scheme, command and dispatch with the geographic information. It is beneficial for the governor to
accurately master the disaster situation and make commands scientifically.
Keywords: earthquake emergency command, disaster situation representation, rapid response
1
Introduction
There are three main measures to deal with the earthquake disaster in the world. One is to strengthen the
earthquake predict, the second is to enhance the quality of building and the third is to improve the
efficiency of the emergency command and rescue during the time of earthquake. But viewed from the
situation of earthquake-preventing and disaster reducing, it is impossible to solve the difficult problems
of earthquake predict and complete the anti-earthquake project in a short time. So, in general, some
measures to enhance the emergency command capacity are adopted to relieve the disaster as much as
possible and stable the social order in the disaster zone.
Taking GIS as the basic platform, the earthquake emergency command information system is a technical
system which provides anti-earthquake and disaster relief services to the government. It owns various
functions, such as earthquake information acquisition, fast assessment, predict scheme management,
earthquake resource management, geographic data management, task plot, command and control,
emergency collaboration, disaster situation presentation, information release, information query and so
on. It is a tool for the governor and the expert to execute the disaster analysis and emergency command,
and a platform for the civilians to cognize the disaster and know of the rescue progress.
2 The Construction of Emergency
Command Information System
Command center
LAN
2.1 The architecture of system
In order to not only meet the needs of data
and system maintenance in LAN and
implementing professional and advanced
analysis, but also meet the needs of
earthquake information release on Internet/
Intranet and the civilian’s disaster information
query, the earthquake emergency command
system adopts a combination architecture [1]
which takes the C/S as the main structure and
the B/S as the auxiliary. Its architecture is as
Client
Application server
Database server
Administrator
Browser
Browser
Client
Web server
Internet
Internet\Intranet
Browser
Browser
Browser
Figure 1 The architecture of system
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Client
Other customer
Client
figure 1.
The C/S architecture has three layers: data service layer, application service layer and client application
layer and adopts the mode of fat client and thin server. Taking the data management as an example,
which includes data defining, query ,edit and update, the data management is run in database server and
in the client, and the system application is implemented by client software. When the client sends data
request to the database server, the server executes the query operation or other business logic. Next, it
obtains the data which includes basic geographic information and earthquake thematic data from the
database, then send the information and data to the client. The client completes the application function
of data. The client also can extract the data subsets from the database server and store them locally to
establish the local database. So the system can run separately from the database server to meet the needs
of mobile user and front command post to execute tasks.
The B/S architecture adopts four layers, namely, the data service layer, application service layer, web
service layer and browser application layer in the client. Utilizing the B/S mode, the data query and
function release are implemented by the software in the browser. In the B/S mode, the program of
business department in the client is designed as universal software, but the function nodes and their
interior functions are privilege- limited. By the authorization, different customer is authorized different
function according his or her privilege, then he or she can not use the other functions. So it can fulfill the
task responsibility and enhance the data safety.
2.2 Data service layer
The earthquake emergency database is responsible for the storage of basic geographic data and different
kinds of earthquake and geology thematic data and provides the necessary data for the query and
dispatch of the earthquake preventing and disaster relief material, predict scheme representation, disaster
analysis, command and control.
2.2.1
The architecture of database management system
The emergency database manages the data
Client Application
by relational database management system.
ArcSDE client
ArcSDE client
The spatial data management utilizes ESRI
(Indirect)
(Direct)
ArcSDE. ArcSDE is a kind of data access
middleware, which can safely and
TCP/IP
effectively access the distributed geographic
ArcSDE application server
database[2]. The architecture of this
SQL command
emergency database management system is
SQL
as figure 2.
SQL engine
2.2.2
The construction flow of database
The
data
managed by the system includes
Storage management
multi-scale basic topographic data, remote
sensing image, DEM data, attribute data,
multimedia data, earthquake and geology
Data file
thematic data and so on. These data are
RDBMS
stored in the Geodatabase in the form of
FeatureDataset. The management, index and
Server
dispatch of data are executed by ArcSDE.
The design process of Geodatabase includes:
Figure 2 The architecture of database
use view modeling, entity and relation
defining, entity representation determination, matching with Geodatabase model, geographic dataset
organization. The former three processes are conceptual modeling process. They are not involved in
concrete modeling and don’t need to consider the type of database model. The latter two processes are
the logic data modeling. Their concrete processes are as follows:
First, the geographic entity is represented as Geodatabase model. Its contents include: the determination
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of the representation type of every kind of geographic entity and topologic relationship, the definition of
attribute field of every kind of entity.
Secondly, the data is stored in the geodatabase. It includes classifying the features into class and
subclass, determining the topologic relationship of features, establishing the geographic dataset and
combining the feature dataset and data class.
For the digital topographic map, the process steps from the original data to final data in database should
include original data checking, layer merging, data format converting, map sheet joining in the same
scale, plane topology and geometric network constructing and so on. In every process step, the data
should be checked in order to control the quality and precision of data. The work flow of putting
topologic map data into database is as figure 3.
ArcGIS Desktop
Original topographic map data
toolkit
Need to check the spatial attribute and coordinate
before and after data conversion
Map layer merge
ArcCatalog
Format conversion
Need to note the
layer s source
’
ArcCatalog
Map sheet join
ArcCatalog
ArcCatalog
Topology reconstruct
The attribute data should
be consistent before and
after topology reconstruct
Check data before and
after it is put into the
database in order to
guarantee its consistence
Put data into database
Figure3 The work flow of putting topologic map data into database
2.2.3
The security mechanism of geographic database
ArcSDE utilizes the security means of database to ensure the safety of geographic data. It doesn’t share
data in file system. The user can’t copy and delete dataset and only can access data by data interface to
guarantee the legality of data access. ArcSDE provides a series of commands to authorize data access.
So it is convenient to authorization management and provides data backup mechanism to safeguard
geographic data and its utility.
2.3 Application service layer and web service layer
2.3.1
Application service layer
The application service layer includes basic GIS service, emergency data service, business logic service,
application module service and so on. The basic GIS service provides basic information analysis service.
The emergency data service mainly is geographic data service which is implemented by ArcSDE. The
business logical service provides the methods that the system needs. The client completes the business
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work by calling the methods. The application modules include a series of analytic computing module,
such as earthquake disaster assessment module which provides the destroy prediction of city building
and lifeline engineering, the assessment of subordinate disaster, economic loss and the civilian
casualty[3]. By utilizing these modules, the client can realize more complicate analysis.
2.3.2
Web service layer
The web service layer is the special layer of B/S in the system. It adopts such tools as WSDL (Web
Service Definition Language), UDDI (Universal Description Discovery and Integration), SOAP (Simple
Object Access Protocol) and techniques to describe, register and release any kind service provided by
the application layer. This layer is transparent to the client. It separates the client layer from the
application service layer. The user’s request of server is packed as SOAP package through the network
and sent to web service layer. After received the package, the web service layer unpacks it and extracts
the request information. Then the service layer sends the information to the application service by the
special communication means of the application service layer. After the application service layer replies
the user with the demanded data, the demanded data is packed as the SOAP package by the web service
and returned to the user. Meanwhile, the web service can realize load balance management. When many
users need to access application server at the same time, the information requests can be effectively sent
to different servers[4].
2.4 Client application layer
The internet \intranet is based on B/S architecture. The client accesses the servers by TCP/IP, SOAP in
the form of web page. The client is used by the public. It displays the disaster information (see figure 4)
released by the command information center and also can execute such simple operations based on GIS
as basic map operation(zoom, roam, query), map analysis (buffer analysis, distance and area analysis)
and so on. Through these functions, the public can rapidly inquire the spatial position and attribute
information related with the earthquake-preventing and disaster reduction on map.
Figure 4
Disaster situation release map
Figure 5 Civilian evacuation route map
The LAN is based on C/S architecture. The client is divided into two kinds. One is for the business
department staff to do some daily maintenance, such as the update of earthquake emergency data,
network control, user’s privilege management and so on. The other is for the leader and earthquake
expert. This kind of client integrates the main subsystem and function modules of emergency command
for disaster assessment, emergency command and decision-making. The command control subsystem is
composed by the modules such as command and control, resource management, command and
communication, monitoring and display. The command and control module is responsible for the
planning, information sending down, monitoring, canceling and modification of task. The resource
management module is responsible for resource allotting and dispatch, monitoring and warning,
resource supplement. The command and communication module is responsible for the message transfer,
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filter control, display, message conversion and so on. The monitoring and display module is responsible
for the map display, GPS positioning, BD satellite positioning, LBS, video display, situation plot display,
communication monitoring and so on. Figure 5 shows the route of evacuating civilian.
The main function modules are as following figure 6 in LAN.
Figure 6 The main function modules of C/S client
3
Conclusion
It is the importance period 24 hours after the earthquake for rescuing, preventing subordinate disaster
occurring and extending. So the time and efficiency of the emergency command is very important and
the responsibility of rescue can’t be neglected. It is very urgent to construct a highly effective
earthquake emergency command information system.
The earthquake emergency command information system provides the government technical support to
rapidly cognize earthquake, acquire the rescue information and evacuate the victims. The intelligent
analytic assessment models can aid decision-making, rapidly response, make emergency scheme and
execute command and dispatch visually based on geographic spatial data. In addition, under the visual
geographic environment, the related government can collaborate smoothly. All those characteristics can
remarkably improve the comprehensive capacity of earthquake-preventing and disaster reduction.
Author in brief:
Zeng Jun: Senior engineer in China. Research interest is GIS applications. Email:[email protected]
Zhang De was born in Hubei, China. He has got his master’s degree for map cartography and GIS
engineer. Now he works in Xi’an research institute of surveying and mapping. His research interests
include GIS application, terrain analysis.
References
[1]. Zeng Jun, et al. Emergency Information Command System for Civil Air Defence [national
technical report]. Xi’an research institute of surveying and mapping, 2009:4~6(in Chinese)
[2]. Xiong Lihua ,Yang Feng. Application Study of Spatial Database Technology Based on ArcSDE.
Computer Engineering and Design,2004,24(3):90~92(in Chinese)
[3]. Meng Xiangrui. The Study of WebGIS-based Earthquake Prevention and Disaster Mitigation
Information System. Jilin University,2005:41~44(in Chinese)
[4]. Zhong Xiao. The Research on the GIS Application in the Earthquake Emergency System and
Earthquake Information Share. The Institute of Earthquake Predict. China Earthquake
Bureau,2006:3~4(in Chinese)
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