Development and application of GIS-based multi-model system for risk assessment of geological hazards

Along with the significant progress of the methods for risk assessment of geological hazards by using GIS, some related systems based on GIS are developed. However, some defects in these systems still exist: each one can only be used for a certain kind of hazard evaluation and only has sole assessment model; the assessment index system and the spatial database can´t be updated easily. Therefore, one GIS-based multi-model system for risk assessment of geological hazards by using Visual Basic 6.0 and secondary development modules of MAPGIS was illustrated in this paper; moreover this system had been applied to the Project of Risk Assessment of Geological Hazards of Central Henan Urban Agglomeration. This system combines the advanced function of GIS spatial analysis with mathematical assessment models and the techniques of software integration development. Comparing with the other systems designed by some researchers, this system has the following advantages: 1. It provides users with 5 different models: exponential-weighted model, fuzzy comprehensive evaluation model, extension matter-element comprehensive evaluation model, spatial information model and artificial neural network model. Thus, user can select multiple models to evaluate one specific hazard and compare respectively different results. 2. It facilitates risk assessment of varied hazards through establishing different assessment index system in an interactive way. 3. It supplies user with updating the spatial database real-timely. 4. It robust offers user the assessment results by different manifestations, such as maps, texts or tables. In the Project of Risk Assessment of Geological Hazards of Central Henan Urban Agglomeration, multiple models mentioned above were selected for multiple types of geological hazards. The results calculated by different models are not only quite similar to own each other, but even to the results of field investigation. This case study demonstrates that the assessment result b- - ased on this system is reliable and practicable.