DSS-Durme is a Decision Support System aimed at the development of integrated spatial plans for the Durme river valley, and more generically, for river valleys in Flanders, Belgium. The system is intended to be used in the following situations:
* to support the design and development of alternative plans and the assessment of the latter;
to stimulate and facilitate discussions relative to alternative plans developed in participatory workshops involving specialists and non-specialists;
to enable communication of alternative solutions and the final solutions chosen to the public at large.[/c]
The initial version of DSS-Durme is intended to be deployed under the supervision of specialists because it is expected that the complexity of the underlying scientific knowledge will require such usage.
The analysis makes use of geographical information in the form of maps as well as output of among others a Mike 11 model. The system is ArcView compatible and able to read maps in a number of commercial GIS formats. For each plot of land, a cellular unit, within the study area calculations are performed. The user will directly generate and manipulate the input of the system by means of 2-D map editors or by importing map material.
The development of an integrated spatial plan for a valley will proceed essentially through the following 5 steps:
* Step 1: The status is assessed of a each plot of land in the valley and relative to the frequency and the depth of flooding as a result of the tidal cycle as well as extreme high and low water events. This calculation ignores the presence of dikes and represents the effects of flooding in the natural situation;
Step 2: Enables the user to designate the areas to be protected against flooding. Different levels of protection can be selected. They will determine at large the potential land use and land cover of the protected plots of land. The result of this step is a map with potential land uses in the valley;
Step 3: Consists in developing a detailed spatial plan for the valley. In the latter the user will determine which of the potential land uses is assigned to each cell in the valley. To that effect he or she will make use of among others the map with the existing land uses. The result of this step is a detailed spatial plan for the valley;
Step 4: Consists in evaluating the particular value and merits of the detailed spatial plan developed in the previous steps. To that effect a number of spatial indicators is calculated measuring among others, the maintenance costs of the dikes, the ecological value, the economic value, etc. To that effect also, the LARCH model and its algorithms relative to the calculation of habitat suitability and habitat fragmentation for a number of key species will be incorporated in the DSS;
Step 5: Consists in the final comparison and assessment of the results generated with a view to select the most appropriate one. The Overlay-Tool and the Map Comparison Kit will be used to apply a spatial Multi Criteria Analysis and a pair wise comparison on the maps of each plan generated. Spatially aggregated and other non-spatial indicators will be evaluated on the basis of Multi Criteria Analysis.[/c]
It goes without saying that the analyst is free to go through the 5 steps as he or she pleases. Steps can be skipped and one is free to jump back to previous steps and reconsider earlier assumptions made or data entered. At each step of the analysis, intermediate results can be stored as part of alternative plans that may be developed consecutively.