have presented difficulties in its design and 
implementation when traditional design methods were 
used. Thus, during, ADES design, a layered architecture 
model that includes both seven layers and relevant 
functions is used to guide the ADES design and 
implementation. Further, the ADES described in this 
paper utilizes a layered model of architecture which 
involves the seven different layers shown in Fig.1. The 
of ADES according to the practical application 
requirements about ADES. Further, we discuss briefly 
each of the layer and the architecture model 
implementation. 
3. ADES ARCHITECTURE IMPLEMENTATION 
  
  
  
  
  
  
  
  
  
Evaluation Application of disaster || Application The environmental disaster 
application evaluation system layer layer(first layer) provides the 
Disaster Evaluation mechanism for managing the 
evaluation layer environmental data about various 
Advanced Decision models for Decision disaster, which include mainly a 
evaluation disaster evaluation layer number of natural disasters about 
Generation of decision data Decision flood, land, pollution and other 
for disaster evaluation data layer natural factors about geographic 
Data management Biological environment. The second 
Basic of biological disaster disaster layer layer(weather ^ disaster ^ layer) 
evaluatio Data management of Weather attempts to make use of the 
weather disaster disaster layer services from the first layer and 
Data management of Environmental provides the means to mange the 
_v | environmental disaster disaster layer data about various weather 
disasters. The basic service of the 
Fig.1 Layer model of Agricultural biological disaster layer(the third 
Disaster Evaluation System layer) is to provide the 
  
  
  
management for data of biological 
disasters. The purpose of layer 4 (decision data layer) is 
to provide a mechanism to generate various data to 
support the decision and evaluation about agricultural 
disasters. The layer complexity depends on the type of 
service it can get from layer 3. The decision layer 
provides a mechanism for making, various decisions for 
agricultural disaster evaluation with the help of a 
number of decision and evaluation models. The 
evaluation layer is concerned with the integrated 
evaluation decisions for a number of special groups of 
agricultural disasters. Its purpose is mainly to define 
various | standard ^ application-oriented ^ evaluation 
decisions. Finally, the application layer which is relevant 
to ADES application provides a means for various users 
or application processes to access ADES. This layer 
contains management functions about the applications 
and some useful mechanisms to support local and remote 
applications. According to the description of various 
layers of the architecture model, ADES architecture 
model implementation can be divided into three 
subsystems. The first is basic evaluation subsystem 
shown in Fig 2, which encompasses the model’s layers 1, 
model is in practice a widely accepted structuring 
technique. The functions of ADES are partitioned into a 
vertical set of layers. Each layer performs a related 
subset of the functions required to exchange information 
with another similar system which has the architecture. 
On the other hand, the ability to exchange information 
can flexibly support the large size of distributed ADES 
design and implementation on a network environment. A 
layer relies on the next lower layer to perform more 
primitive functions and to conceal details of those 
functions. It provides services to the next higher layer. 
Ideally, the layers should be defined so that changes in 
one layer do not require changes in the other layers. 
Thus, we have decomposed one complex problem about 
how to construct ADES into a number of more 
manageable subproblems. The task of our research team 
was to define a set of layers and the services performed 
by each layer in order to make the design and 
implementation of ADES become more simple and easy. 
Further, the partitioning should group functions 
logically, should have enough layers to make each layer 
manageably small, but should not have so many layers 
that the processing, overhead imposed by the collection of 
layer burdensome. Thus, we define carefully all functions 
  
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International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B7. Vienna 1996 
  
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