The ECOSIM Information System Framework
The ECOSIM Demonstrator builds on a generic environmental information
system framework developed by ESS.
The underlying development environment and tools are provided by the
ESS ACA ToolKit,
an integrated set of more than 1,000 functions, utility programs,
and object classes, designed to support the efficient building of interactive
information and decision support systems in the domain of environmental
planning and management.
The Project Gallery provides
a number of example projects and products based on the ACA ToolKit.
The generic information system framework consists of:
GUI, menu system and main event loops;
geographic information system (GIS)
object data base including object editing and display functions
embedded rule-based expert system
hypertext system and embedded WWW browser;
Within this framework, using a generic
based on the TCP/IP and the http protocol, individual information
resources such as data bases and simulations models can be linked and
GUI, menu system and main event loops
The information system framework is based on a fully menu driven,
largely symbolic and graphical user interface. Almost all user interaction
consists of point, drag, and click operations. Text input, wherever
possible, uses multiple-choice selection rather than text input (typing)
to minimize the potential for operator error.
Menus, selections, and a range of graphical analog data entry tools
(sliders, compass, etc.)
are all context sensitive and constrained to feasible ranges or choice sets to ensure consistent and plausible user
The various icon menus and option selectors are coordinated by event
loops and callbacks that translate the interactive user specifications
into the appropriate actions.
Consistent layout across pages, use of colors and fonts aims to simplify
interpretation and learning within the system. A status bar and an
embedded help- and explain hypertext system (see below) provide guidance
for the novice or infrequent user.
Geographic information system (GIS)
Almost all objects in the environmental information system are spatially
referenced. As a major integrating tool, an
embedded GIS manages these
The GIS provides a smooth integration of different formats (vectors,
graphs, rasters, cell-grids, DEMs, TINs, FE and FD model grids,
dynamic model output). Its main function is to provide a spatially
organized interface to the system's data objects and associated functions,
as well as the display and analysis of (spatially distributed) model results.
Object data base, object editing and display functions
The information system is based on an
object oriented design. This approach supports the representation
and structuring of the problem domain in terms of natural, real-world
objects and related information requests in a format and style that is
directly understandable and useful for the end user.
It supports a problem (and therefor user) oriented rather than
a data or model oriented view of the problem domain.
Objects or object classes in this framework include:
- individual functional components such as emission sources, power
plants, treatment plants, observation stations, etc.
- related data such as observation time series or emission inventories;
- the individual variables or parameters that define the attributes or
properties of compound objects (Descriptors in the expert systems
- structural and geographic elements such as road segments, city
blocks or districts, hydrographical catchments, parks, etc.;
- tasks or decision scenarios;
- individual analytical tools such as simulation models.
Embedded rule-based expert system
As an important generic function of the framework, an embedded
rule-based expert system is used to assist the user in the definition of
decision and input variables, as well as in the interpretation of results.
In addition, the expert system can be used a classification tool,
Environmental Impact Assessment tasks, in its own right.
The expert system uses near-natural language
Rules (first order logic)
and as its variables Descriptors .
In an interactive dialogue, the system compiles information from the user
that it uses in an inference process to deduce its answers (i.e., updated
attributes of objects in a changed context).
Hypertext system and embedded WWW browser
The hypertext system is embedded with the overall user interface as a help-
and explain function associated with information icons throught the user
interface. It also provides meta-data and background information on
individual objects such as the descriptors of the expert systems, a model,
or a decision scenario.
In line with the distributed network architecture of the system,
the hypertext browser can use both an internal hypertext format as well as
with a (parallel) embedded web browser HTML documents.
This supports direct access to local HTML pages as well as to
the entire Internet.